linalg.py 132.0 KB
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#   Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
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import numpy as np
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import paddle
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from paddle import _C_ops
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from paddle.common_ops_import import VarDesc

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from ..common_ops_import import Variable
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from ..fluid.data_feeder import (
    check_dtype,
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    check_type,
    check_variable_and_dtype,
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)
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from ..framework import LayerHelper, in_dynamic_mode
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from .creation import full
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from .manipulation import cast
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from .math import _get_reduce_axis
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__all__ = []

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# Consistent with kDefaultDim from C++ Backend
K_DEFAULT_DIM = 9

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def transpose(x, perm, name=None):
    """
    Permute the data dimensions of `input` according to `perm`.

    The `i`-th dimension  of the returned tensor will correspond to the
    perm[i]-th dimension of `input`.

    Args:
        x (Tensor): The input Tensor. It is a N-D Tensor of data types bool, float32, float64, int32.
        perm (list|tuple): Permute the input according to the data of perm.
        name (str): The name of this layer. It is optional.

    Returns:
        Tensor: A transposed n-D Tensor, with data type being bool, float32, float64, int32, int64.

    For Example:

        .. code-block:: text

         x = [[[ 1  2  3  4] [ 5  6  7  8] [ 9 10 11 12]]
             [[13 14 15 16] [17 18 19 20] [21 22 23 24]]]
         shape(x) =  [2,3,4]

         # Example 1
         perm0 = [1,0,2]
         y_perm0 = [[[ 1  2  3  4] [13 14 15 16]]
                   [[ 5  6  7  8]  [17 18 19 20]]
                   [[ 9 10 11 12]  [21 22 23 24]]]
         shape(y_perm0) = [3,2,4]

         # Example 2
         perm1 = [2,1,0]
         y_perm1 = [[[ 1 13] [ 5 17] [ 9 21]]
                   [[ 2 14] [ 6 18] [10 22]]
                   [[ 3 15]  [ 7 19]  [11 23]]
                   [[ 4 16]  [ 8 20]  [12 24]]]
         shape(y_perm1) = [4,3,2]

    Examples:

        .. code-block:: python

            import paddle

            x = paddle.randn([2, 3, 4])
            x_transposed = paddle.transpose(x, perm=[1, 0, 2])
            print(x_transposed.shape)
            # [3L, 2L, 4L]

    """
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    if in_dynamic_mode():
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        return _C_ops.transpose(x, perm)
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    else:
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        check_variable_and_dtype(
            x,
            'x',
            [
                'bool',
                'float16',
                'float32',
                'float64',
                'int32',
                'int64',
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                'uint16',
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                'complex64',
                'complex128',
            ],
            'transpose',
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        )
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        check_type(perm, 'perm', (list, tuple), 'transpose')
        if isinstance(perm, tuple):
            perm = list(perm)
        if len(perm) != len(x.shape):
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            raise ValueError(
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                "Input(perm) is the permutation of dimensions of Input(x), "
                "its length should be equal to dimensions of Input(x), "
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                "but received dimension of Input(x) is {}, "
                "the length of Input(perm) is {}.".format(
                    len(x.shape), len(perm)
                )
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            )
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        for idx, dim in enumerate(perm):
            if dim >= len(x.shape):
                raise ValueError(
                    "Each element in Input(perm) should be less than Input(x)'s dimension, "
                    "but %d-th element in Input(perm) is %d which exceeds Input(x)'s "
                    "dimension %d." % (idx, perm[idx], len(x.shape))
                )
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        helper = LayerHelper('transpose', **locals())
        out = helper.create_variable_for_type_inference(x.dtype)
        x_shape = helper.create_variable_for_type_inference(x.dtype)
        helper.append_op(
            type='transpose2',
            inputs={'X': [x]},
            outputs={'Out': [out], 'XShape': [x_shape]},
            attrs={'axis': perm},
        )
        return out
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def matmul(x, y, transpose_x=False, transpose_y=False, name=None):
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    """
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    Applies matrix multiplication to two tensors. `matmul` follows
    the complete broadcast rules,
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    and its behavior is consistent with `np.matmul`.
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    Currently, the input tensors' number of dimensions can be any, `matmul` can be used to
    achieve the `dot`, `matmul` and `batchmatmul`.
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    The actual behavior depends on the shapes of :math:`x`, :math:`y` and the
    flag values of :attr:`transpose_x`, :attr:`transpose_y`. Specifically:

    - If a transpose flag is specified, the last two dimensions of the tensor
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      are transposed. If the tensor is ndim-1 of shape, the transpose is invalid. If the tensor
      is ndim-1 of shape :math:`[D]`, then for :math:`x` it is treated as :math:`[1, D]`, whereas
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      for :math:`y` it is the opposite: It is treated as :math:`[D, 1]`.

    The multiplication behavior depends on the dimensions of `x` and `y`. Specifically:

    - If both tensors are 1-dimensional, the dot product result is obtained.

    - If both tensors are 2-dimensional, the matrix-matrix product is obtained.

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    - If the `x` is 1-dimensional and the `y` is 2-dimensional,
      a `1` is prepended to its dimension in order to conduct the matrix multiply.
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      After the matrix multiply, the prepended dimension is removed.
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    - If the `x` is 2-dimensional and `y` is 1-dimensional,
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      the matrix-vector product is obtained.

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    - If both arguments are at least 1-dimensional and at least one argument
      is N-dimensional (where N > 2), then a batched matrix multiply is obtained.
      If the first argument is 1-dimensional, a 1 is prepended to its dimension
      in order to conduct the batched matrix multiply and removed after.
      If the second argument is 1-dimensional, a 1 is appended to its
      dimension for the purpose of the batched matrix multiple and removed after.
      The non-matrix (exclude the last two dimensions) dimensions are
      broadcasted according the broadcast rule.
      For example, if input is a (j, 1, n, m) tensor and the other is a (k, m, p) tensor,
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      out will be a (j, k, n, p) tensor.
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    Args:
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        x (Tensor): The input tensor which is a Tensor.
        y (Tensor): The input tensor which is a Tensor.
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        transpose_x (bool, optional): Whether to transpose :math:`x` before multiplication.
        transpose_y (bool, optional): Whether to transpose :math:`y` before multiplication.
        name(str, optional): A name for this layer(optional). If set None, the layer
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            will be named automatically.

    Returns:
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        Tensor: The output Tensor.
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    Examples:

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        .. code-block:: python

            import paddle

            # vector * vector
            x = paddle.rand([10])
            y = paddle.rand([10])
            z = paddle.matmul(x, y)
            print(z.shape)
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            # ()
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            # matrix * vector
            x = paddle.rand([10, 5])
            y = paddle.rand([5])
            z = paddle.matmul(x, y)
            print(z.shape)
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            # (10,)
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            # batched matrix * broadcasted vector
            x = paddle.rand([10, 5, 2])
            y = paddle.rand([2])
            z = paddle.matmul(x, y)
            print(z.shape)
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            # (10, 5)
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            # batched matrix * batched matrix
            x = paddle.rand([10, 5, 2])
            y = paddle.rand([10, 2, 5])
            z = paddle.matmul(x, y)
            print(z.shape)
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            # (10, 5, 5)
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            # batched matrix * broadcasted matrix
            x = paddle.rand([10, 1, 5, 2])
            y = paddle.rand([1, 3, 2, 5])
            z = paddle.matmul(x, y)
            print(z.shape)
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            # (10, 3, 5, 5)
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    """
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    if in_dynamic_mode():
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        return _C_ops.matmul(x, y, transpose_x, transpose_y)
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    else:
        attrs = {
            'trans_x': transpose_x,
            'trans_y': transpose_y,
        }
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        def __check_input(x, y):
            var_names = {'x': x, 'y': y}
            for name, val in var_names.items():
                check_variable_and_dtype(
                    val,
                    name,
                    [
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                        'uint16',
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                        'float16',
                        'float32',
                        'float64',
                        'complex64',
                        'complex128',
                    ],
                    'matmul',
                )
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        __check_input(x, y)
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        helper = LayerHelper('matmul_v2', **locals())
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
        helper.append_op(
            type='matmul_v2',
            inputs={'X': x, 'Y': y},
            outputs={'Out': out},
            attrs=attrs,
        )
        return out
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def norm(x, p='fro', axis=None, keepdim=False, name=None):
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    """
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    Returns the matrix norm (Frobenius) or vector norm (the 1-norm, the Euclidean
    or 2-norm, and in general the p-norm for p > 0) of a given tensor.

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    Note:
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        This norm API is different from `numpy.linalg.norm`.
        This api supports high-order input tensors (rank >= 3), and certain axis need to be pointed out to calculate the norm.
        But `numpy.linalg.norm` only supports 1-D vector or 2-D matrix as input tensor.
        For p-order matrix norm, this api actually treats matrix as a flattened vector to calculate the vector norm, NOT REAL MATRIX NORM.

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    Args:
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        x (Tensor): The input tensor could be N-D tensor, and the input data
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            type could be float32 or float64.
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        p (float|string, optional): Order of the norm. Supported values are `fro`, `0`, `1`, `2`,
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            `inf`, `-inf` and any positive real number yielding the corresponding p-norm. Not supported: ord < 0 and nuclear norm.
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            Default value is `fro`.
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        axis (int|list|tuple, optional): The axis on which to apply norm operation. If axis is int
            or list(int)/tuple(int)  with only one element, the vector norm is computed over the axis.
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            If `axis < 0`, the dimension to norm operation is rank(input) + axis.
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            If axis is a list(int)/tuple(int) with two elements, the matrix norm is computed over the axis.
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            Default value is `None`.
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        keepdim (bool, optional): Whether to reserve the reduced dimension in the
            output Tensor. The result tensor will have fewer dimension
            than the :attr:`input` unless :attr:`keepdim` is true, default
            value is False.
        name (str, optional): The default value is None. Normally there is no need for
            user to set this property. For more information, please refer to :ref:`api_guide_Name`.

    Returns:
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        Tensor: results of norm operation on the specified axis of input tensor,
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        it's data type is the same as input's Tensor.
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    Examples:
        .. code-block:: python
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            import paddle
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            x = paddle.arange(24, dtype="float32").reshape([2, 3, 4]) - 12
            # x: Tensor(shape=[2, 3, 4], dtype=float32, place=Place(cpu), stop_gradient=True,
            #          [[[-12., -11., -10., -9. ],
            #            [-8. , -7. , -6. , -5. ],
            #            [-4. , -3. , -2. , -1. ]],

            #           [[ 0. ,  1. ,  2. ,  3. ],
            #            [ 4. ,  5. ,  6. ,  7. ],
            #            [ 8. ,  9. ,  10.,  11.]]])
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            # compute frobenius norm along last two dimensions.
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            out_fro = paddle.linalg.norm(x, p='fro', axis=[0,1])
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            # out_fro: Tensor(shape=[4], dtype=float32, place=Place(cpu), stop_gradient=True,
            #                 [17.43559647, 16.91153526, 16.73320007, 16.91153526])
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            # compute 2-order vector norm along last dimension.
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            out_pnorm = paddle.linalg.norm(x, p=2, axis=-1)
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            # out_pnorm: Tensor(shape=[2, 3], dtype=float32, place=Place(cpu), stop_gradient=True,
            #                [[21.11871147, 13.19090557, 5.47722578 ],
            #                 [3.74165750 , 11.22497177, 19.13112640]])
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            # compute 2-order  norm along [0,1] dimension.
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            out_pnorm = paddle.linalg.norm(x, p=2, axis=[0,1])
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            # out_pnorm: Tensor(shape=[4], dtype=float32, place=Place(cpu), stop_gradient=True,
            #                  [17.43559647, 16.91153526, 16.73320007, 16.91153526])
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            # compute inf-order  norm
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            out_pnorm = paddle.linalg.norm(x, p=float("inf"))
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            # out_pnorm  = Tensor(shape=[], dtype=float32, place=Place(cpu), stop_gradient=True,
            #                    12.)
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            out_pnorm = paddle.linalg.norm(x, p=float("inf"), axis=0)
            # out_pnorm: Tensor(shape=[3, 4], dtype=float32, place=Place(cpu), stop_gradient=True,
            #                 [[12., 11., 10., 9. ],
            #                  [8. , 7. , 6. , 7. ],
            #                  [8. , 9. , 10., 11.]])
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            # compute -inf-order  norm
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            out_pnorm = paddle.linalg.norm(x, p=-float("inf"))
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            # out_pnorm: Tensor(shape=[], dtype=float32, place=Place(cpu), stop_gradient=True,
            #                  0.)
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            out_pnorm = paddle.linalg.norm(x, p=-float("inf"), axis=0)
            # out_pnorm: Tensor(shape=[3, 4], dtype=float32, place=Place(cpu), stop_gradient=True,
            #                  [[0., 1., 2., 3.],
            #                  [4., 5., 6., 5.],
            #                  [4., 3., 2., 1.]])
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    """

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    def frobenius_norm(input, dim=None, keepdim=False, name=None):
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        """
        The frobenius norm OP is to calculate the frobenius norm of certain two dimensions of Tensor `input`.
        Args:
          input (Variable): Tensor, data type float32, float64.
          dim (list, optional): None for last two dimensions.
          keepdim (bool, optional): Whether keep the dimensions as the `input`, Default False.
        """
        if dim is not None and not (isinstance(dim, list) and len(dim) == 2):
            raise ValueError(
                "The dim of frobenius norm op should be None or two elements list!"
            )
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        if in_dynamic_mode():
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            if dim is None:
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                return _C_ops.frobenius_norm(input, [], keepdim, True)
            return _C_ops.frobenius_norm(input, dim, keepdim, False)
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        else:
            attrs = {'dim': dim, 'keep_dim': keepdim, 'reduce_all': False}
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            if dim is None:
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                attrs['reduce_all'] = True
            check_variable_and_dtype(
                input, 'input', ['float32', 'float64'], 'frobenius_norm'
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            )
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            helper = LayerHelper('frobenius_norm', **locals())
            out = helper.create_variable_for_type_inference(
                dtype=helper.input_dtype()
            )
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            helper.append_op(
                type='frobenius_norm',
                inputs={'X': input},
                outputs={'Out': out},
                attrs=attrs,
            )
            return out
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    def vector_norm(
        input, porder=None, axis=None, keepdim=False, asvector=False, name=None
    ):
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        """
        Calculate the p-order vector norm for certain  dimension of Tensor `input`.
        Args:
          input (Variable): Tensor, data type float32, float64.
          porder (float, optional): None for porder=2.0.
          axis (int, optional): None for last dimension.
          keepdim (bool, optional): Whether keep the dimensions as the `input`, Default False.
        """
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        if in_dynamic_mode():
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            if axis is None:
                axis = -1
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            return _C_ops.p_norm(input, porder, axis, 1e-12, keepdim, asvector)
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        else:
            if porder is not None:
                check_type(porder, 'porder', (float, int), 'p_norm')
            if axis is not None:
                check_type(axis, 'axis', (int), 'p_norm')
            check_variable_and_dtype(
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                input,
                'input',
                ['float16', 'uint16', 'float32', 'float64'],
                'p_norm',
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            )
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            attrs = {
                'axis': axis if axis is not None else -1,
                'porder': float(porder) if porder is not None else 2.0,
                'keepdim': keepdim,
                'asvector': asvector,
                'epsilon': 1e-12,
            }
            helper = LayerHelper('p_norm', **locals())
            out = helper.create_variable_for_type_inference(
                dtype=helper.input_dtype()
            )
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            helper.append_op(
                type='p_norm',
                inputs={'X': input},
                outputs={'Out': out},
                attrs=attrs,
            )
            return out
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    def inf_norm(
        input, porder=None, axis=axis, keepdim=False, asvector=False, name=None
    ):
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        if in_dynamic_mode():
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            out = _C_ops.abs(input)
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            if porder == np.float64('inf'):
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                return _C_ops.max(out, axis, keepdim)
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            else:
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                return _C_ops.min(out, axis, keepdim)
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        else:
            helper = LayerHelper('inf_norm', **locals())
            out = helper.create_variable_for_type_inference(
                dtype=helper.input_dtype()
            )
            helper.append_op(
                type='abs', inputs={'X': input}, outputs={'Out': out}
            )
            reduce_out = helper.create_variable_for_type_inference(
                dtype=helper.input_dtype()
            )
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            reduce_all, axis = _get_reduce_axis(axis, x)
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            reduce_type = (
                'reduce_max' if porder == np.float64('inf') else 'reduce_min'
            )
            helper.append_op(
                type=reduce_type,
                inputs={'X': out},
                outputs={'Out': reduce_out},
                attrs={
                    'dim': axis,
                    'keep_dim': keepdim,
                    'reduce_all': reduce_all,
                },
            )
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            return reduce_out
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    def p_matrix_norm(input, porder=1.0, axis=axis, keepdim=False, name=None):
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        """
        NOTE:
            This function actually treats the matrix as flattened vector to calculate vector norm instead of matrix norm.
        """
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        if in_dynamic_mode():
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            abs_out = _C_ops.abs(input)
            pow_out = _C_ops.pow(abs_out, porder)
            sum_out = _C_ops.sum(pow_out, axis, None, keepdim)
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            out = _C_ops.pow(sum_out, float(1.0 / porder))
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            return out

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        block = LayerHelper('norm', **locals())
        out = block.create_variable_for_type_inference(
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            dtype=block.input_dtype()
        )
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        abs_out = block.create_variable_for_type_inference(
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            dtype=block.input_dtype()
        )
        block.append_op(
            type='abs', inputs={'X': input}, outputs={'Out': abs_out}
        )
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        pow_out = block.create_variable_for_type_inference(
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            dtype=block.input_dtype()
        )
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        block.append_op(
            type='pow',
            inputs={'X': abs_out},
            outputs={'Out': pow_out},
            attrs={'factor': porder},
        )
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        sum_out = block.create_variable_for_type_inference(
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            dtype=block.input_dtype()
        )
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        reduce_all, axis = _get_reduce_axis(axis, x)
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        block.append_op(
            type='reduce_sum',
            inputs={'X': pow_out},
            outputs={'Out': sum_out},
            attrs={
                'dim': axis,
                'keep_dim': keepdim,
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                'reduce_all': reduce_all,
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            },
        )
        block.append_op(
            type='pow',
            inputs={'X': sum_out},
            outputs={'Out': out},
            attrs={'factor': float(1.0 / porder)},
        )
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        return out

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    if axis is None and p is not None:
        if isinstance(p, str):
            if p == "fro":
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                return frobenius_norm(x, dim=axis, keepdim=keepdim, name=name)
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            else:
                raise ValueError(
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                    f"only valid string values are 'fro', found {p}"
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                )
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        elif isinstance(p, (int, float)):
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            return vector_norm(
                x,
                porder=p,
                axis=axis,
                keepdim=keepdim,
                asvector=True,
                name=name,
            )
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        else:
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            raise ValueError(
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                f"only valid p type is string or float, found {type(p)}"
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            )
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    if isinstance(axis, tuple):
        axis = list(axis)
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    if isinstance(axis, list) and len(axis) == 1:
        axis = axis[0]

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    # calculate vector norm, where axis is int or list with only one integer
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    if isinstance(axis, int):
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        if isinstance(p, str):
            if p == "fro":
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                return vector_norm(
                    x,
                    porder=2,
                    axis=axis,
                    keepdim=keepdim,
                    asvector=False,
                    name=name,
                )
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            else:
                raise ValueError(
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                    f"only valid string values are 'fro', found {p}"
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                )
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        elif isinstance(p, (int, float)):
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            return vector_norm(
                x,
                axis=axis,
                porder=p,
                keepdim=keepdim,
                asvector=False,
                name=name,
            )
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        else:
            raise ValueError(
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                "unspport p for p-order vector norm. except float, found {}".format(
                    p
                )
            )
    # calculate matrix norm, where axis is list with two integers
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    elif isinstance(axis, list) and len(axis) == 2:
        if p == "fro":
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            return frobenius_norm(x, dim=axis, keepdim=keepdim, name=name)
        elif p == np.inf or p == -np.inf:
            return inf_norm(x, porder=p, axis=axis, keepdim=keepdim, name=name)
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        elif p == 0:
            raise ValueError(
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                "just support axis type int or list (length of list <=1) if p = 0, found {}".format(
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                    axis
                )
            )
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        else:
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            return p_matrix_norm(
                x, porder=p, axis=axis, keepdim=keepdim, name=name
            )
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    else:
        raise ValueError(
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            "except axis type int or list (length of list <=2), found {}".format(
                axis
            )
        )
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def dist(x, y, p=2, name=None):
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    r"""
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    Returns the p-norm of (x - y). It is not a norm in a strict sense, only as a measure
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    of distance. The shapes of x and y must be broadcastable. The definition is as follows, for
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    details, please refer to the `Introduction to Tensor <../../guides/beginner/tensor_en.html#chapter5-broadcasting-of-tensor>`_:
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    - Each input has at least one dimension.
    - Match the two input dimensions from back to front, the dimension sizes must either be equal, one of them is 1, or one of them does not exist.

    Where, z = x - y, the shapes of x and y are broadcastable, then the shape of z can be
    obtained as follows:

    1. If the number of dimensions of x and y are not equal, prepend 1 to the dimensions of the
    tensor with fewer dimensions.

    For example, The shape of x is [8, 1, 6, 1], the shape of y is [7, 1, 5], prepend 1 to the
    dimension of y.

    x (4-D Tensor):  8 x 1 x 6 x 1

    y (4-D Tensor):  1 x 7 x 1 x 5

    2. Determine the size of each dimension of the output z: choose the maximum value from the
    two input dimensions.

    z (4-D Tensor):  8 x 7 x 6 x 5

    If the number of dimensions of the two inputs are the same, the size of the output can be
    directly determined in step 2. When p takes different values, the norm formula is as follows:
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    When p = 0, defining $0^0=0$, the zero-norm of z is simply the number of non-zero elements of z.

    .. math::

        ||z||_{0}=\lim_{p \\rightarrow 0}\sum_{i=1}^{m}|z_i|^{p}

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    When p = inf, the inf-norm of z is the maximum element of the absolute value of z.
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    .. math::

        ||z||_\infty=\max_i |z_i|

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    When p = -inf, the negative-inf-norm of z is the minimum element of the absolute value of z.
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    .. math::

        ||z||_{-\infty}=\min_i |z_i|

    Otherwise, the p-norm of z follows the formula,

    .. math::

        ||z||_{p}=(\sum_{i=1}^{m}|z_i|^p)^{\\frac{1}{p}}

    Args:
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        x (Tensor): 1-D to 6-D Tensor, its data type is bfloat16, float16, float32 or float64.
        y (Tensor): 1-D to 6-D Tensor, its data type is bfloat16, float16, float32 or float64.
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        p (float, optional): The norm to be computed, its data type is float32 or float64. Default: 2.
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        name (str, optional): The default value is `None`. Normally there is no need for
            user to set this property. For more information, please refer to :ref:`api_guide_Name`.
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    Returns:
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        Tensor: Tensor that is the p-norm of (x - y).
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    Examples:
        .. code-block:: python

            import paddle

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            x = paddle.to_tensor([[3, 3],[3, 3]], dtype="float32")
            y = paddle.to_tensor([[3, 3],[3, 1]], dtype="float32")
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            out = paddle.dist(x, y, 0)
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            print(out) # out = 1.
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            out = paddle.dist(x, y, 2)
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            print(out) # out = 2.
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            out = paddle.dist(x, y, float("inf"))
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            print(out) # out = 2.
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            out = paddle.dist(x, y, float("-inf"))
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            print(out) # out = 0.
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    """
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    if in_dynamic_mode():
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        return _C_ops.dist(x, y, p)
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    check_variable_and_dtype(
        x, 'dtype', ['bfloat16', 'float16', 'float32', 'float64'], 'dist'
    )
    check_variable_and_dtype(
        y, 'dtype', ['bfloat16', 'float16', 'float32', 'float64'], 'dist'
    )
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    check_type(p, 'p', (float, int), 'dist')
    helper = LayerHelper("dist", **locals())
    out = helper.create_variable_for_type_inference(x.dtype)

    inputs = {"X": [x], "Y": [y]}
    outputs = {'Out': [out]}
    attrs = {"p": float(p)}
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    helper.append_op(
        type='dist', inputs=inputs, outputs={'Out': out}, attrs=attrs
    )
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    return out
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def cond(x, p=None, name=None):
    """

    Computes the condition number of a matrix or batches of matrices with respect to a matrix norm ``p``.

    Args:
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        x (Tensor): The input tensor could be tensor of shape ``(*, m, n)`` where ``*`` is zero or more batch dimensions
            for ``p`` in ``(2, -2)``, or of shape ``(*, n, n)`` where every matrix is invertible for any supported ``p``.
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            And the input data type could be ``float32`` or ``float64``.
        p (float|string, optional): Order of the norm. Supported values are `fro`, `nuc`, `1`, `-1`, `2`, `-2`,
            `inf`, `-inf`. Default value is `None`, meaning that the order of the norm is `2`.
        name (str, optional): The default value is `None`. Normally there is no need for
            user to set this property. For more information, please refer to :ref:`api_guide_Name`.

    Returns:
        Tensor: computing results of condition number, its data type is the same as input Tensor ``x``.

    Examples:
        .. code-block:: python

            import paddle

            x = paddle.to_tensor([[1., 0, -1], [0, 1, 0], [1, 0, 1]])

            # compute conditional number when p is None
            out = paddle.linalg.cond(x)
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            # Tensor(shape=[], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        1.41421342)
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            # compute conditional number when order of the norm is 'fro'
            out_fro = paddle.linalg.cond(x, p='fro')
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            # Tensor(shape=[], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        3.16227770)
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            # compute conditional number when order of the norm is 'nuc'
            out_nuc = paddle.linalg.cond(x, p='nuc')
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            # Tensor(shape=[], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        9.24263859)
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            # compute conditional number when order of the norm is 1
            out_1 = paddle.linalg.cond(x, p=1)
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            # Tensor(shape=[], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        2.)
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            # compute conditional number when order of the norm is -1
            out_minus_1 = paddle.linalg.cond(x, p=-1)
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            # Tensor(shape=[], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        1.)
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            # compute conditional number when order of the norm is 2
            out_2 = paddle.linalg.cond(x, p=2)
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            # Tensor(shape=[], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        1.41421342)
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            # compute conditional number when order of the norm is -1
            out_minus_2 = paddle.linalg.cond(x, p=-2)
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            # Tensor(shape=[], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        0.70710683)
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            # compute conditional number when order of the norm is inf
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            out_inf = paddle.linalg.cond(x, p=float("inf"))
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            # Tensor(shape=[], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        2.)
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            # compute conditional number when order of the norm is -inf
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            out_minus_inf = paddle.linalg.cond(x, p=-float("inf"))
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            # Tensor(shape=[], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        1.)
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            a = paddle.randn([2, 4, 4])
            # Tensor(shape=[2, 4, 4], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        [[[-0.06784091, -0.07095790,  1.31792855, -0.58959651],
            #          [ 0.20818676, -0.85640615, -0.89998871, -1.47439921],
            #          [-0.49132481,  0.42250812, -0.77383220, -2.19794774],
            #          [-0.33551720, -1.70003879, -1.09795380, -0.63737559]],

            #         [[ 1.12026262, -0.16119350, -1.21157813,  2.74383283],
            #          [-0.15999718,  0.18798758, -0.69392562,  1.35720372],
            #          [-0.53013402, -2.26304483,  1.40843511, -1.02288902],
            #          [ 0.69533503,  2.05261683, -0.02251151, -1.43127477]]])

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            a_cond_fro = paddle.linalg.cond(a, p='fro')
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            # Tensor(shape=[2], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        [8.86691189 , 75.23817444])

            b = paddle.randn([2, 3, 4])
            # Tensor(shape=[2, 3, 4], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        [[[-0.43754861,  1.80796063, -0.78729683, -1.82264030],
            #          [-0.27670753,  0.06620564,  0.29072434, -0.31155765],
            #          [ 0.34123746, -0.05444612,  0.05001324, -1.46877074]],

            #         [[-0.64331555, -1.51103854, -1.26277697, -0.68024760],
            #          [ 2.59375715, -1.06665540,  0.96575671, -0.73330832],
            #          [-0.47064447, -0.23945692, -0.95150250, -1.07125998]]])
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            b_cond_2 = paddle.linalg.cond(b, p=2)
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            # Tensor(shape=[2], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            #        [6.64228773, 3.89068866])
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    """

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    def mat_norm(input, porder=1.0, axis=None):
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        """
        NOTE:
            Calculate the matrix norm of a square matrix or batches of square matrices,
            when porder is in (1, -1, inf, -inf)
        """
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        if in_dynamic_mode():
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            abs_out = _C_ops.abs(input)
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            sum_out = _C_ops.sum(abs_out, axis, None, False)
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            if porder == 1 or porder == np.inf:
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                return _C_ops.max(sum_out, [-1], False)
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            if porder == -1 or porder == -np.inf:
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                return _C_ops.min(sum_out, [-1], False)
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        else:
            block = LayerHelper('norm', **locals())
            abs_out = block.create_variable_for_type_inference(
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                dtype=block.input_dtype()
            )
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            sum_out = block.create_variable_for_type_inference(
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                dtype=block.input_dtype()
            )
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            out = block.create_variable_for_type_inference(
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                dtype=block.input_dtype()
            )
            block.append_op(
                type='abs', inputs={'X': input}, outputs={'Out': abs_out}
            )
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            reduce_all, axis = _get_reduce_axis(axis, x)
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            block.append_op(
                type='reduce_sum',
                inputs={'X': abs_out},
                outputs={'Out': sum_out},
                attrs={
                    'dim': axis,
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                    'keep_dim': False,
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                    'reduce_all': reduce_all,
                },
            )
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            if porder == 1 or porder == np.inf:
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                block.append_op(
                    type='reduce_max',
                    inputs={'X': sum_out},
                    outputs={'Out': out},
                    attrs={
                        'dim': [-1],
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                        'keep_dim': False,
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                        'reduce_all': reduce_all,
                    },
                )
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            if porder == -1 or porder == -np.inf:
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                block.append_op(
                    type='reduce_min',
                    inputs={'X': sum_out},
                    outputs={'Out': out},
                    attrs={
                        'dim': [-1],
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                        'keep_dim': False,
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                        'reduce_all': reduce_all,
                    },
                )
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            return out
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    def fro_norm(input, porder=2, axis=[-1]):
        """
        NOTE:
            Calculate the frobenius norm of a square matrix or batches of square matrices.
        """
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        if in_dynamic_mode():
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            pow_out = _C_ops.pow(input, porder)
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            sum_out_1 = _C_ops.sum(pow_out, axis, None, False)
            sum_out_2 = _C_ops.sum(sum_out_1, axis, None, False)
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            return _C_ops.pow(sum_out_2, float(1.0 / porder))
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        else:
            block = LayerHelper('norm', **locals())
            pow_out = block.create_variable_for_type_inference(
                dtype=block.input_dtype()
            )
            sum_out_1 = block.create_variable_for_type_inference(
                dtype=block.input_dtype()
            )
            sum_out_2 = block.create_variable_for_type_inference(
                dtype=block.input_dtype()
            )
            out = block.create_variable_for_type_inference(
                dtype=block.input_dtype()
            )
            block.append_op(
                type='pow',
                inputs={'X': input},
                outputs={'Out': pow_out},
                attrs={'factor': porder},
            )
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            reduce_all, axis = _get_reduce_axis(axis, x)
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            block.append_op(
                type='reduce_sum',
                inputs={'X': pow_out},
                outputs={'Out': sum_out_1},
                attrs={
                    'dim': axis,
                    'keep_dim': False,
                    'reduce_all': reduce_all,
                },
            )
            block.append_op(
                type='reduce_sum',
                inputs={'X': sum_out_1},
                outputs={'Out': sum_out_2},
                attrs={
                    'dim': axis,
                    'keep_dim': False,
                    'reduce_all': reduce_all,
                },
            )
            block.append_op(
                type='pow',
                inputs={'X': sum_out_2},
                outputs={'Out': out},
                attrs={'factor': float(1.0 / porder)},
            )
            return out
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    def svd_norm(input, porder, axis=[-1]):
        """
        NOTE:
            Calculate the matrix norm, which is related to singular values, of a matrix
            or batches of matrices, including nuclear norm, 2-norm and (-2)-norm.
        """
        u, s, vh = svd(input, full_matrices=False)

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        if in_dynamic_mode():
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            if porder == "nuc":
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                return _C_ops.sum(s, axis, None, False)
            max_out = _C_ops.max(s, axis, False)
            min_out = _C_ops.min(s, axis, False)
            if porder == 2:
                return _C_ops.divide(max_out, min_out)
            if porder == -2:
                return _C_ops.divide(min_out, max_out)
        else:
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            reduce_all, axis = _get_reduce_axis(axis, x)
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            block = LayerHelper('norm', **locals())
            out = block.create_variable_for_type_inference(
                dtype=block.input_dtype()
            )
            if porder == "nuc":
                block.append_op(
                    type='reduce_sum',
                    inputs={'X': s},
                    outputs={'Out': out},
                    attrs={
                        'dim': axis,
                        'keep_dim': False,
                        'reduce_all': reduce_all,
                    },
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                )
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                return out
            max_out = block.create_variable_for_type_inference(
                dtype=block.input_dtype()
            )
            min_out = block.create_variable_for_type_inference(
                dtype=block.input_dtype()
            )
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            block.append_op(
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                type='reduce_max',
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                inputs={'X': s},
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                outputs={'Out': max_out},
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                attrs={
                    'dim': axis,
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                    'keep_dim': False,
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                    'reduce_all': reduce_all,
                },
            )
            block.append_op(
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                type='reduce_min',
                inputs={'X': s},
                outputs={'Out': min_out},
                attrs={
                    'dim': axis,
                    'keep_dim': False,
                    'reduce_all': reduce_all,
                },
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            )
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            if porder == 2:
                block.append_op(
                    type='elementwise_div',
                    inputs={'X': max_out, 'Y': min_out},
                    outputs={'Out': out},
                    attrs={'aixs': axis, 'use_mkldnn': False},
                )
                return out
            if porder == -2:
                block.append_op(
                    type='elementwise_div',
                    inputs={'X': min_out, 'Y': max_out},
                    outputs={'Out': out},
                    attrs={'aixs': axis, 'use_mkldnn': False},
                )
                return out
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    def empty_tensor(input, shape):
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        if in_dynamic_mode():
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            return input.reshape(shape)
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        raise ValueError(
            "only support x is nonempty tensor in static graph mode"
        )
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    x_shape = list(x.shape)
    if not len(x_shape) >= 2:
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        raise ValueError(
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            "input should be a matrix or batches of matrices, "
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            + f"but the dimention of received input is {len(x_shape)}"
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        )
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    if p is None:
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        p = 2
    x_size = 0 if (0 in x_shape) else 1
    if p in ("fro", "nuc", 1, -1, np.inf, -np.inf):
        if x_shape[len(x_shape) - 1] == x_shape[len(x_shape) - 2]:
            if x_size == 0:
                return empty_tensor(x, x_shape[:-2])
            x_inv = x.inverse()
            if p == "fro":
                return fro_norm(x) * fro_norm(x_inv)
            if p == "nuc":
                return svd_norm(x, p) * svd_norm(x_inv, p)
            if p in (1, -1):
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                return mat_norm(x, porder=p, axis=[-2]) * mat_norm(
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                    x_inv, porder=p, axis=[-2]
                )
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            if p in (np.inf, -np.inf):
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                return mat_norm(x, porder=p, axis=[-1]) * mat_norm(
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                    x_inv, porder=p, axis=[-1]
                )
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        else:
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            raise ValueError(
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                f"only support p is {p} when input is a "
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                + "square matrix or batches of square matrices"
            )
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    elif p in (2, -2):
        if x_size == 0:
            return empty_tensor(x, x_shape[:-2])
        return svd_norm(x, porder=p)
    else:
        raise ValueError(
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            f"unsupported {p} for p, only supporting ('fro', 'nuc', "
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            + "1, -1, 2, -2, inf, -inf) or none"
        )
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def dot(x, y, name=None):
    """
    This operator calculates inner product for vectors.
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    Note:
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       Support 1-d and 2-d Tensor. When it is 2d, the first dimension of this matrix
       is the batch dimension, which means that the vectors of multiple batches are dotted.
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    Parameters:
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        x(Tensor): 1-D or 2-D ``Tensor``. Its dtype should be ``float32``, ``float64``, ``int32``, ``int64``
        y(Tensor): 1-D or 2-D ``Tensor``. Its dtype soulde be ``float32``, ``float64``, ``int32``, ``int64``
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        name(str, optional): Name of the output. Default is None. It's used to print debug info for developers. Details: :ref:`api_guide_Name`

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    Returns:
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        Tensor: the calculated result Tensor.
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    Examples:

    .. code-block:: python

        import paddle
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        # 1-D Tensor * 1-D Tensor
        x = paddle.to_tensor([1, 2, 3])
        y = paddle.to_tensor([4, 5, 6])
        z = paddle.dot(x, y)
1100
        print(z)  # 32
1101 1102 1103 1104

        # 2-D Tensor * 2-D Tensor
        x = paddle.to_tensor([[1, 2, 3], [2, 4, 6]])
        y = paddle.to_tensor([[4, 5, 6], [4, 5, 6]])
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        z = paddle.dot(x, y)
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        print(z)  # [32, 64]
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    """
1109
    if in_dynamic_mode():
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        return _C_ops.dot(x, y)
1111 1112
    else:
        op_type = 'dot'
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        assert x is not None, f'x cannot be None in {op_type}'
        assert y is not None, f'y cannot be None in {op_type}'
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1117
        check_variable_and_dtype(
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            x,
            'x',
            ['float16', 'uint16', 'float32', 'float64', 'int32', 'int64'],
            op_type,
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        )
        check_variable_and_dtype(
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            y,
            'y',
            ['float16', 'uint16', 'float32', 'float64', 'int32', 'int64'],
            op_type,
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        )
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        helper = LayerHelper(op_type, **locals())
        if name is None:
            out = helper.create_variable_for_type_inference(dtype=x.dtype)
        else:
            out = helper.create_variable(
                name=name, dtype=x.dtype, persistable=False
            )
        helper.append_op(
            type="dot", inputs={'X': x, 'Y': y}, attrs={}, outputs={"Out": out}
1139
        )
1140
        return out
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def cov(x, rowvar=True, ddof=True, fweights=None, aweights=None, name=None):
    """
    Estimate the covariance matrix of the input variables, given data and weights.

    A covariance matrix is a square matrix, indicate the covariance of each pair variables in the input matrix.
1148
    For example, for an N-dimensional samples X=[x1,x2,…xN]T, then the covariance matrix
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    element Cij is the covariance of xi and xj. The element Cii is the variance of xi itself.

    Parameters:
        x(Tensor): A N-D(N<=2) Tensor containing multiple variables and observations. By default, each row of x represents a variable. Also see rowvar below.
        rowvar(Bool, optional): If rowvar is True (default), then each row represents a variable, with observations in the columns. Default: True
        ddof(Bool, optional): If ddof=True will return the unbiased estimate, and ddof=False will return the simple average. Default: True
        fweights(Tensor, optional): 1-D Tensor of integer frequency weights; The number of times each observation vector should be repeated. Default: None
        aweights(Tensor, optional): 1-D Tensor of observation vector weights. How important of the observation vector, larger data means this element is more important. Default: None
        name(str, optional): Name of the output. Default is None. It's used to print debug info for developers. Details: :ref:`api_guide_Name`

    Returns:
        Tensor: The covariance matrix Tensor of the variables.

    Examples:

    .. code-block:: python

        import paddle

1168
        xt = paddle.rand((3, 4))
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        paddle.linalg.cov(xt)

        '''
        Tensor(shape=[3, 3], dtype=float64, place=CUDAPlace(0), stop_gradient=True,
            [[0.07918842, 0.06127326, 0.01493049],
                [0.06127326, 0.06166256, 0.00302668],
                [0.01493049, 0.00302668, 0.01632146]])
        '''
    """
    op_type = 'cov'
    if len(x.shape) > 2 or len(x.shape) < 1:
        raise ValueError(
            "Input(x) only support N-D (1<=N<=2) tensor in cov, but received "
1182 1183
            "length of Input(input) is %s." % len(x.shape)
        )
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    check_variable_and_dtype(x, 'dtype', ['float32', 'float64'], 'cov')
    nx = x
    if len(x.shape) == 1:
        nx = x.reshape((1, -1))
    if not rowvar and nx.shape[0] != 1:
        nx = nx.t()
    w = None
    observation_num = nx.shape[1]
    if fweights is not None:
        w = fweights.astype(nx.dtype)
        if len(w.shape) > 1:
            raise ValueError(
                "Input(fweights) only support N-D (N<=1) tensor in cov, but received "
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                "shape of Input(input) is %s." % len(fweights.shape)
            )
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        if fweights.shape[0] != observation_num:
            raise ValueError(
                "The number of Input(fweights) should equal to x's dim[1]: {}, but received "
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                "size of Input(fweights) is {}.".format(
                    observation_num, fweights.shape[0]
                )
            )
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        if fweights.min() < 0:
            raise ValueError(
                "The value of Input(fweights) cannot be negtive, but received "
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                "min of Input(fweights) is {}.".format(fweights.min())
            )
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        if not paddle.all(fweights == paddle.round(fweights.astype('float64'))):
            raise ValueError("Input(fweights) must be integer ")

    if aweights is not None:
        aw = aweights.astype(nx.dtype)
        if len(aw.shape) > 1:
            raise ValueError(
                "Input(aweights) only support N-D (N<=1) tensor in cov, but received "
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                "length of Input(input) is %s." % len(aweights.shape)
            )
        check_variable_and_dtype(
            aweights, 'dtype', ['float32', 'float64'], 'cov'
        )
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        if aweights.shape[0] != observation_num:
            raise ValueError(
                "The number of Input(aweights) should equal to x's dim[1]: {}, but received "
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                "size of Input(aweights) is {}.".format(
                    observation_num, aweights.shape[0]
                )
            )
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        if aweights.min() < 0:
            raise ValueError(
                "The value of Input(aweights) cannot be negtive, but received "
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                "min of Input(aweights) is {}.".format(aweights.min())
            )
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        if w is not None:
            w = w * aw
        else:
            w = aw

    w_sum = paddle.to_tensor(observation_num, dtype=nx.dtype)
    if fweights is not None or aweights is not None:
        w_sum = w.sum()
        if w_sum.item() == 0:
            raise ValueError("The sum of weights is zero, can't be normalized.")

    if w is not None:
        nx_w = nx * w
        avg = (nx_w).sum(axis=1) / w_sum
    else:
        avg = nx.sum(axis=1) / w_sum
        nx_w = nx

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    if w is not None and aweights is not None and ddof:
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        norm_factor = w_sum - (w * aweights).sum() / w_sum
    else:
        norm_factor = w_sum - ddof
    if norm_factor <= 0:
        norm_factor = paddle.to_tensor(0, dtype=nx.dtype)
    nx = nx - avg.unsqueeze(1)
    xxt = paddle.mm(nx, nx_w.t().conj())
    cov = paddle.divide(xxt, norm_factor).squeeze()
    return cov


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def t(input, name=None):
    """
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    Transpose <=2-D tensor.
    0-D and 1-D tensors are returned as it is and 2-D tensor is equal to
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    the paddle.transpose function which perm dimensions set 0 and 1.
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1272
    Args:
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        input (Tensor): The input Tensor. It is a N-D (N<=2) Tensor of data types float32, float64, int32, int64.
1274
        name(str, optional): The default value is None.  Normally there is no need for
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            user to set this property.  For more information, please refer to :ref:`api_guide_Name`
    Returns:
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        Tensor: A transposed n-D Tensor, with data type being float16, float32, float64, int32, int64.
1278

1279
    Examples:
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1281 1282 1283
        .. code-block:: python
           :name: code-example
             import paddle
1284

1285
             # Example 1 (0-D tensor)
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             x = paddle.to_tensor([0.79])
             paddle.t(x) # [0.79]
1288

1289
             # Example 2 (1-D tensor)
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             x = paddle.to_tensor([0.79, 0.84, 0.32])
             paddle.t(x) # [0.79000002, 0.83999997, 0.31999999]
             paddle.t(x).shape # [3]
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             # Example 3 (2-D tensor)
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             x = paddle.to_tensor([[0.79, 0.84, 0.32],
                                  [0.64, 0.14, 0.57]])
             x.shape # [2, 3]
             paddle.t(x)
             # [[0.79000002, 0.63999999],
             #  [0.83999997, 0.14000000],
             #  [0.31999999, 0.56999999]]
             paddle.t(x).shape # [3, 2]
1303

1304 1305 1306 1307 1308
    """
    if len(input.shape) > 2:
        raise ValueError(
            "Input(input) only support N-D (N<=2) tensor, but received "
            "length of Input(input) is %s. Perhaps you can use paddle."
1309 1310
            "tensor.transpose() instead." % len(input.shape)
        )
1311
    if in_dynamic_mode():
1312
        if len(input.shape) <= 1:
1313 1314 1315
            return input
        # 2-D tensor
        perm = [1, 0]
1316
        out = _C_ops.transpose(input, perm)
1317
        return out
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    else:
        check_variable_and_dtype(
            input,
            'input',
            ['float16', 'float32', 'float64', 'int32', 'int64'],
            'transpose',
        )
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1326 1327 1328
        helper = LayerHelper('t', **locals())
        out = helper.create_variable_for_type_inference(input.dtype)
        input_shape = helper.create_variable_for_type_inference(input.dtype)
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        if len(input.shape) <= 1:
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            out = input
        else:
            helper.append_op(
                type='transpose2',
                inputs={'X': [input]},
                outputs={'Out': [out], 'XShape': [input_shape]},
                attrs={'axis': [1, 0]},
            )
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        return out

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def cross(x, y, axis=9, name=None):
1342
    """
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    Computes the cross product between two tensors along an axis.
1344

1345 1346
    Inputs must have the same shape, and the length of their axes should be equal to 3.
    If `axis` is not given, it defaults to the first axis found with the length 3.
1347

1348
    Args:
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        x (Tensor): The first input tensor, the data type is float16, float32, float64, int32, int64.
        y (Tensor): The second input tensor, the data type is float16, float32, float64, int32, int64.
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        axis (int, optional): The axis along which to compute the cross product. It defaults to be 9 which indicates using the first axis found with the length 3.
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        name (str, optional): Name for the operation (optional, default is None). For more information, please refer to :ref:`api_guide_Name`.
1353 1354

    Returns:
1355
        Tensor. A Tensor with same data type as `x`.
1356

1357 1358
    Examples:
        .. code-block:: python
1359

1360
            import paddle
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            x = paddle.to_tensor([[1.0, 1.0, 1.0],
                                  [2.0, 2.0, 2.0],
                                  [3.0, 3.0, 3.0]])
            y = paddle.to_tensor([[1.0, 1.0, 1.0],
                                  [1.0, 1.0, 1.0],
                                  [1.0, 1.0, 1.0]])
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1369 1370 1371 1372 1373 1374 1375 1376 1377
            z1 = paddle.cross(x, y)
            # [[-1. -1. -1.]
            #  [ 2.  2.  2.]
            #  [-1. -1. -1.]]

            z2 = paddle.cross(x, y, axis=1)
            # [[0. 0. 0.]
            #  [0. 0. 0.]
            #  [0. 0. 0.]]
1378
    """
1379
    if in_dynamic_mode():
1380
        axis = K_DEFAULT_DIM if axis is None else axis
1381
        return _C_ops.cross(x, y, axis)
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    else:
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        check_variable_and_dtype(
            x,
            'x',
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            ['float16', 'uint16', 'float32', 'float64', "int32", "int64"],
1387 1388 1389 1390 1391
            'cross',
        )
        check_variable_and_dtype(
            y,
            'y',
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            ['float16', 'uint16', 'float32', 'float64', "int32", "int64"],
1393 1394
            'cross',
        )
1395 1396
        helper = LayerHelper("cross", **locals())
        out = helper.create_variable_for_type_inference(x.dtype)
1397
        attrs = {}
1398
        attrs['dim'] = axis
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        helper.append_op(
            type='cross',
            inputs={'X': x, 'Y': y},
            outputs={'Out': out},
            attrs=attrs,
        )
        return out
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1409
def cholesky(x, upper=False, name=None):
1410
    r"""
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    Computes the Cholesky decomposition of one symmetric positive-definite
1412 1413
    matrix or batches of symmetric positive-definite matrice.

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    If `upper` is `True`, the decomposition has the form :math:`A = U^{T}U` ,
    and the returned matrix :math:`U` is upper-triangular. Otherwise, the
    decomposition has the form  :math:`A = LL^{T}` , and the returned matrix
    :math:`L` is lower-triangular.

    Args:
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        x (Tensor): The input tensor. Its shape should be `[*, M, M]`,
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            where * is zero or more batch dimensions, and matrices on the
            inner-most 2 dimensions all should be symmetric positive-definite.
            Its data type should be float32 or float64.
        upper (bool): The flag indicating whether to return upper or lower
            triangular matrices. Default: False.
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        name (str, optional): Name for the operation (optional, default is None).
            For more information, please refer to :ref:`api_guide_Name`.
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    Returns:
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        Tensor, A Tensor with same shape and data type as `x`. It represents
        triangular matrices generated by Cholesky decomposition.
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    Examples:
        .. code-block:: python

            import paddle

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            a = paddle.rand([3, 3], dtype="float32")
            a_t = paddle.transpose(a, [1, 0])
            x = paddle.matmul(a, a_t) + 1e-03

1442
            out = paddle.linalg.cholesky(x, upper=False)
1443
            print(out)
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    """
1445
    if in_dynamic_mode():
1446
        return _C_ops.cholesky(x, upper)
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    else:
        check_variable_and_dtype(x, 'dtype', ['float32', 'float64'], 'cholesky')
        check_type(upper, 'upper', bool, 'cholesky')
        helper = LayerHelper('cholesky', **locals())
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
        helper.append_op(
            type='cholesky',
            inputs={'X': [x]},
            outputs={'Out': out},
            attrs={'upper': upper},
        )
        return out
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def matrix_rank(x, tol=None, hermitian=False, name=None):
    r"""
    Computes the rank of a matrix.

1465
    The rank of a matrix is the number of singular values that are greater than the specified `tol` threshold when hermitian=False,
1466
    or the number of eigenvalues in absolute value that are greater than the specified `tol` threshold when hermitian=True.
1467 1468

    Args:
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        x (Tensor): The input tensor. Its shape should be `[..., m, n]`, where `...` is zero or more batch dimensions. If `x` is a batch
            of matrices then the output has the same batch dimensions. The data type of `x` should be float32 or float64.
        tol (float,Tensor,optional): the tolerance value. Default: None. If `tol` is not specified, and `sigma` is the largest
            singular value (or eigenvalues in absolute value), and `eps` is the epsilon value for the dtype of `x`, then `tol` is computed
1473
            with formula `tol=sigma * max(m,n) * eps`. Note that if `x` is a batch of matrices, `tol` is computed this way for every batch.
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        hermitian (bool,optional): indicates whether `x` is Hermitian. Default: False. When hermitian=True, `x` is assumed to be Hermitian,
            enabling a more efficient method for finding eigenvalues, but `x` is not checked inside the function. Instead, We just use
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            the lower triangular of the matrix to compute.
1477 1478 1479 1480
        name (str, optional): Name for the operation (optional, default is None). For more information, please refer to :ref:`api_guide_Name`.

    Returns:
        Tensor: Rank of tensor x.
1481

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    Examples:
        .. code-block:: python

            import paddle

            a = paddle.eye(10)
            b = paddle.linalg.matrix_rank(a)
            print(b)
1490
            # b = 10
1491 1492 1493 1494 1495 1496 1497

            c = paddle.ones(shape=[3, 4, 5, 5])
            d = paddle.linalg.matrix_rank(c, tol=0.01, hermitian=True)
            print(d)
            # d = [[1, 1, 1, 1],
            #      [1, 1, 1, 1],
            #      [1, 1, 1, 1]]
1498

1499
    """
1500
    if in_dynamic_mode():
1501 1502 1503 1504 1505 1506
        if isinstance(tol, Variable):
            if tol.dtype != x.dtype:
                tol_tensor = cast(tol, x.dtype)
            else:
                tol_tensor = tol
            use_default_tol = False
1507 1508 1509
            return _C_ops.matrix_rank_tol(
                x, tol_tensor, use_default_tol, hermitian
            )
1510

1511 1512 1513 1514 1515 1516
        if tol is None:
            tol_attr = 0.0
            use_default_tol = True
        else:
            tol_attr = float(tol)
            use_default_tol = False
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        return _C_ops.matrix_rank(x, tol_attr, use_default_tol, hermitian)
1518 1519 1520 1521 1522
    else:
        inputs = {}
        attrs = {}
        check_variable_and_dtype(x, 'x', ['float32', 'float64'], 'matrix_rank')
        inputs['X'] = x
1523
        if tol is None:
1524
            attrs['use_default_tol'] = True
1525
        elif isinstance(tol, Variable):
1526
            attrs['use_default_tol'] = False
1527
            if tol.dtype != x.dtype:
1528
                inputs['TolTensor'] = cast(tol, x.dtype)
1529
            else:
1530
                inputs['TolTensor'] = tol
1531
        else:
1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543
            check_type(tol, 'tol', float, 'matrix_rank')
            attrs['use_default_tol'] = False
            attrs['tol'] = tol
        check_type(hermitian, 'hermitian', bool, 'matrix_rank')
        attrs['hermitian'] = hermitian

        helper = LayerHelper('matrix_rank', **locals())
        out = helper.create_variable_for_type_inference(dtype='int32')
        helper.append_op(
            type='matrix_rank', inputs=inputs, outputs={'Out': out}, attrs=attrs
        )
        return out
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def bmm(x, y, name=None):
    """
    Applies batched matrix multiplication to two tensors.

    Both of the two input tensors must be three-dementional and share the same batch size.

    if x is a (b, m, k) tensor, y is a (b, k, n) tensor, the output will be a (b, m, n) tensor.

    Args:
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        x (Tensor): The input Tensor.
        y (Tensor): The input Tensor.
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        name(str|None): A name for this layer(optional). If set None, the layer
            will be named automatically.

    Returns:
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        Tensor: The product Tensor.
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    Examples:
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        .. code-block:: python

            import paddle
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            # In imperative mode:
            # size x: (2, 2, 3) and y: (2, 3, 2)
            x = paddle.to_tensor([[[1.0, 1.0, 1.0],
                                [2.0, 2.0, 2.0]],
                                [[3.0, 3.0, 3.0],
                                [4.0, 4.0, 4.0]]])
            y = paddle.to_tensor([[[1.0, 1.0],[2.0, 2.0],[3.0, 3.0]],
                                [[4.0, 4.0],[5.0, 5.0],[6.0, 6.0]]])
            out = paddle.bmm(x, y)
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            # Tensor(shape=[2, 2, 2], dtype=float32, place=Place(cpu), stop_gradient=True,
            #        [[[6. , 6. ],
            #          [12., 12.]],

            #         [[45., 45.],
            #          [60., 60.]]])
1583

1584
    """
1585
    if in_dynamic_mode():
1586
        return _C_ops.bmm(x, y)
1587
    else:
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        x_shape = x.shape
        y_shape = y.shape
        if not len(x_shape) == len(y_shape) == 3:
            raise ValueError(
                "x and y should be 3-dimensional. But received x's dimention: {}, y's dimention: {}".format(
                    x_shape, y_shape
                )
            )
        if x_shape[2] != y_shape[1]:
            raise ValueError(
                "x's width must be equal with y's height. But received x's shape: {}, y's shape: {}".format(
                    x_shape, y_shape
                )
            )
        if x_shape[0] != y_shape[0]:
            raise ValueError(
                "x's batch (shape[0]) must be equal with y's batch (shape[0]). But received x's shape: {}, y's shape: {}".format(
                    x_shape, y_shape
                )
            )
1608 1609 1610 1611 1612 1613
        helper = LayerHelper('bmm', **locals())
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
        helper.append_op(
            type='bmm', inputs={'X': x, 'Y': y}, outputs={'Out': out}
        )
        return out
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1616
def histogram(input, bins=100, min=0, max=0, name=None):
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    """
1618
    Computes the histogram of a tensor. The elements are sorted into equal width bins between min and max.
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    If min and max are both zero, the minimum and maximum values of the data are used.

    Args:
1622
        input (Tensor): A Tensor(or LoDTensor) with shape :math:`[N_1, N_2,..., N_k]` . The data type of the input Tensor
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            should be float32, float64, int32, int64.
1624 1625 1626 1627
        bins (int, optional): number of histogram bins.
        min (int, optional): lower end of the range (inclusive).
        max (int, optional): upper end of the range (inclusive).
        name (str, optional): For details, please refer to :ref:`api_guide_Name`. Generally, no setting is required. Default: None.
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    Returns:
1630
        Tensor: data type is int64, shape is (nbins,).
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1632
    Examples:
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        .. code-block:: python
1634

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            import paddle
1636

1637
            inputs = paddle.to_tensor([1, 2, 1])
1638 1639
            result = paddle.histogram(inputs, bins=4, min=0, max=3)
            print(result) # [0, 2, 1, 0]
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    """
1641
    if in_dynamic_mode():
1642
        return _C_ops.histogram(input, bins, min, max)
1643 1644 1645 1646
    else:
        helper = LayerHelper('histogram', **locals())
        check_variable_and_dtype(
            input, 'X', ['int32', 'int64', 'float32', 'float64'], 'histogram'
1647
        )
1648 1649 1650 1651 1652 1653 1654 1655
        out = helper.create_variable_for_type_inference(VarDesc.VarType.INT64)
        helper.append_op(
            type='histogram',
            inputs={'X': input},
            outputs={'Out': out},
            attrs={'bins': bins, 'min': min, 'max': max},
        )
        return out
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def bincount(x, weights=None, minlength=0, name=None):
    """
1660
    Computes frequency of each value in the input tensor.
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    Args:
        x (Tensor): A Tensor with non-negative integer. Should be 1-D tensor.
        weights (Tensor, optional): Weight for each value in the input tensor. Should have the same shape as input. Default is None.
        minlength (int, optional): Minimum number of bins. Should be non-negative integer. Default is 0.
        name(str, optional): The default value is None.  Normally there is no need for user to set this
            property.  For more information, please refer to :ref:`api_guide_Name`.

    Returns:
        Tensor: The tensor of frequency.

    Examples:
        .. code-block:: python

            import paddle

            x = paddle.to_tensor([1, 2, 1, 4, 5])
            result1 = paddle.bincount(x)
            print(result1) # [0, 2, 1, 0, 1, 1]

            w = paddle.to_tensor([2.1, 0.4, 0.1, 0.5, 0.5])
            result2 = paddle.bincount(x, weights=w)
            print(result2) # [0., 2.19999981, 0.40000001, 0., 0.50000000, 0.50000000]
    """
    if x.dtype not in [paddle.int32, paddle.int64]:
        raise TypeError("Elements in Input(x) should all be integers")

1688
    if in_dynamic_mode():
1689
        return _C_ops.bincount(x, weights, minlength)
1690 1691
    else:
        helper = LayerHelper('bincount', **locals())
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1693
        check_variable_and_dtype(x, 'X', ['int32', 'int64'], 'bincount')
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1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709
        if weights is not None:
            check_variable_and_dtype(
                weights,
                'Weights',
                ['int32', 'int64', 'float32', 'float64'],
                'bincount',
            )
            out = helper.create_variable_for_type_inference(dtype=weights.dtype)
        else:
            out = helper.create_variable_for_type_inference(dtype=x.dtype)
        helper.append_op(
            type='bincount',
            inputs={'X': x, 'Weights': weights},
            outputs={'Out': out},
            attrs={'minlength': minlength},
1710
        )
1711
        return out
1712 1713 1714 1715 1716 1717 1718


def mv(x, vec, name=None):
    """
    Performs a matrix-vector product of the matrix x and the vector vec.

    Args:
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        x (Tensor): A tensor with shape :math:`[M, N]` , The data type of the input Tensor x
1720
            should be one of float32, float64.
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        vec (Tensor): A tensor with shape :math:`[N]` , The data type of the input Tensor x
1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736
            should be one of float32, float64.
        name(str, optional): The default value is None.  Normally there is no need for user to set this
            property.  For more information, please refer to :ref:`api_guide_Name`.

    Returns:
        Tensor: The tensor which is producted by x and vec.

    Examples:
        .. code-block:: python

            # x: [M, N], vec: [N]
            # paddle.mv(x, vec)  # out: [M]

            import paddle

1737 1738
            x = paddle.to_tensor([[2, 1, 3], [3, 0, 1]]).astype("float64")
            vec = paddle.to_tensor([3, 5, 1]).astype("float64")
1739
            out = paddle.mv(x, vec)
1740 1741 1742
            print(out)
            # Tensor(shape=[2], dtype=float64, place=Place(cpu), stop_gradient=True,
            #        [14., 10.])
1743
    """
1744
    if in_dynamic_mode():
1745
        return _C_ops.mv(x, vec)
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    else:
1747

1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759
        def __check_input(x, vec):
            var_names = {'x': x, 'vec': vec}
            for name, val in var_names.items():
                check_variable_and_dtype(
                    val, name, ['float32', 'float64'], 'mv'
                )
            x_shape = list(x.shape)
            vec_shape = list(vec.shape)
            if len(x_shape) != 2:
                raise ValueError(
                    "x should be 2-dimensional. But received x's dimention: {}".format(
                        x_shape
1760
                    )
1761 1762 1763 1764 1765
                )
            if len(vec_shape) != 1:
                raise ValueError(
                    "vec should be 1-dimensional. But received vec's dimention: {}".format(
                        vec_shape
1766
                    )
1767
                )
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1769
        __check_input(x, vec)
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        helper = LayerHelper('mv', **locals())
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
        helper.append_op(
            type='mv', inputs={'X': x, 'Vec': vec}, outputs={'Out': out}
        )
        return out
1777 1778


1779
def det(x, name=None):
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    """
1781

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    Calculates determinant value of a square matrix or batches of square matrices.
1783

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    Args:
1785
        x (Tensor): the input matrix of size `(n, n)` or the
1786 1787
            batch of matrices of size `(*, n, n)` where `*` is one or more
            batch dimensions.
1788 1789
        name(str, optional): Name of the output. Default is None. It's used
            to print debug info for developers. Details: :ref:`api_guide_Name`
1790

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    Returns:
1792
        Tensor, the determinant value of a square matrix or batches of square matrices.
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1794
    Examples:
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        .. code-block:: python

1797
            import paddle
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1799
            x =  paddle.randn([3,3,3])
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1801
            A = paddle.linalg.det(x)
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1803
            print(A)
1804

1805
            # [ 0.02547996,  2.52317095, -6.15900707])
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1806

1807

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    """
1809
    if in_dynamic_mode():
1810
        return _C_ops.det(x)
1811
    else:
1812
        check_dtype(x.dtype, 'Input', ['float16', 'float32', 'float64'], 'det')
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        input_shape = list(x.shape)
        assert len(input_shape) >= 2, (
            "The x must be at least 2-dimensional, "
            "but received Input x's dimensional: %s.\n" % len(input_shape)
        )
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1820 1821
        assert (
            input_shape[-1] == input_shape[-2]
1822
        ), "Expect squared input," "but received {} by {} matrix.\n".format(
1823 1824 1825 1826 1827
            input_shape[-2],
            input_shape[-1],
        )
        helper = LayerHelper('determinant', **locals())
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
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1829 1830 1831 1832
        helper.append_op(
            type='determinant', inputs={'Input': [x]}, outputs={'Out': [out]}
        )
        return out
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1835
def slogdet(x, name=None):
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    """
1837

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    Calculates the sign and natural logarithm of the absolute value of a square matrix's or batches square matrices' determinant.
1839
    The determinant can be computed with ``sign * exp`` (logabsdet)
1840

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    Supports input of float, double

    Note that for matrices that have zero determinant, this returns ``(0, -inf)``
1844

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    Args:
        x (Tensor): the batch of matrices of size :math:`(*, n, n)`
            where math:`*` is one or more batch dimensions.

    Returns:
1850
        y (Tensor), A tensor containing the sign of the determinant and the natural logarithm
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        of the absolute value of determinant, respectively.

1853
    Examples:
1854
        .. code-block:: python
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1856
            import paddle
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1858
            x =  paddle.randn([3,3,3])
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1860
            A = paddle.linalg.slogdet(x)
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1862
            print(A)
1863

1864 1865
            # [[ 1.        ,  1.        , -1.        ],
            # [-0.98610914, -0.43010661, -0.10872950]])
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    """
1868
    if in_dynamic_mode():
1869
        return _C_ops.slogdet(x)
1870 1871
    else:
        check_dtype(x.dtype, 'Input', ['float32', 'float64'], 'slogdet')
1872

1873 1874 1875 1876 1877
        input_shape = list(x.shape)
        assert len(input_shape) >= 2, (
            "The x must be at least 2-dimensional, "
            "but received Input x's dimensional: %s.\n" % len(input_shape)
        )
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1879 1880
        assert (
            input_shape[-1] == input_shape[-2]
1881
        ), "Expect squared input," "but received {} by {} matrix.\n".format(
1882 1883 1884 1885 1886
            input_shape[-2],
            input_shape[-1],
        )
        helper = LayerHelper('slogdeterminant', **locals())
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
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1888 1889 1890 1891 1892 1893
        helper.append_op(
            type='slogdeterminant',
            inputs={'Input': [x]},
            outputs={'Out': [out]},
        )
        return out
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1896 1897
def svd(x, full_matrices=False, name=None):
    r"""
1898 1899 1900 1901 1902
    Computes the singular value decomposition of one matrix or a batch of regular matrices.

    Let :math:`X` be the input matrix or a batch of input matrices, the output should satisfies:

    .. math::
1903 1904
        X = U * diag(S) * VT

1905 1906
    Args:
        x (Tensor): The input tensor. Its shape should be `[..., N, M]`,
1907
            where `...` is zero or more batch dimensions. N and M can be arbitraty
1908 1909
            positive number. Note that if x is sigular matrices, the grad is numerical
            instable. The data type of x should be float32 or float64.
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        full_matrices (bool, optional): A flag to control the behavor of svd.
1911
            If full_matrices = True, svd op will compute full U and V matrics,
1912
            which means shape of U is `[..., N, N]`, shape of V is `[..., M, M]`. K = min(M, N).
1913
            If full_matrices = False, svd op will use a economic method to store U and V.
1914
            which means shape of U is `[..., N, K]`, shape of V is `[..., M, K]`. K = min(M, N).
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            Default value is False.
1916
        name (str, optional): Name for the operation (optional, default is None).
1917
            For more information, please refer to :ref:`api_guide_Name`.
1918 1919

    Returns:
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        - U (Tensor), is the singular value decomposition result U.
        - S (Tensor), is the singular value decomposition result S.
        - VH (Tensor), VH is the conjugate transpose of V, which is the singular value decomposition result V.

        Tuple of 3 tensors(U, S, VH): VH is the conjugate transpose of V. S is the singlar value vectors of matrics with shape `[..., K]`
1925

1926 1927 1928 1929
    Examples:
        .. code-block:: python

            import paddle
1930 1931 1932

            x = paddle.to_tensor([[1.0, 2.0], [1.0, 3.0], [4.0, 6.0]]).astype('float64')
            x = x.reshape([3, 2])
1933
            u, s, vh = paddle.linalg.svd(x)
1934 1935 1936 1937 1938
            print (u)
            #U = [[ 0.27364809, -0.21695147  ],
            #      [ 0.37892198, -0.87112408 ],
            #      [ 0.8840446 ,  0.44053933 ]]

1939
            print (s)
1940
            #S = [8.14753743, 0.78589688]
1941
            print (vh)
1942 1943
            #VT= [[ 0.51411221,  0.85772294],
            #     [ 0.85772294, -0.51411221]]
1944

1945
            # one can verify : U * S * VT == X
1946
            #                  U * UH == I
1947
            #                  V * VH == I
1948
    """
1949

1950
    if in_dynamic_mode():
1951
        return _C_ops.svd(x, full_matrices)
1952 1953 1954 1955 1956 1957 1958
    else:
        check_variable_and_dtype(x, 'dtype', ['float32', 'float64'], 'svd')
        check_type(full_matrices, 'full_matrices', bool, 'svd')
        helper = LayerHelper('svd', **locals())
        u = helper.create_variable_for_type_inference(dtype=x.dtype)
        vh = helper.create_variable_for_type_inference(dtype=x.dtype)
        s = helper.create_variable_for_type_inference(dtype=x.dtype)
1959
        attrs = {}
1960 1961 1962 1963 1964 1965 1966 1967
        attrs['full_matrices'] = full_matrices
        helper.append_op(
            type='svd',
            inputs={'X': [x]},
            outputs={'U': u, 'VH': vh, 'S': s},
            attrs=attrs,
        )
        return u, s, vh
1968 1969


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def pca_lowrank(x, q=None, center=True, niter=2, name=None):
    r"""
    Performs linear Principal Component Analysis (PCA) on a low-rank matrix or batches of such matrices.

    Let :math:`X` be the input matrix or a batch of input matrices, the output should satisfies:

    .. math::
        X = U * diag(S) * V^{T}

    Args:
        x (Tensor): The input tensor. Its shape should be `[..., N, M]`,
            where `...` is zero or more batch dimensions. N and M can be arbitraty
            positive number. The data type of x should be float32 or float64.
        q (int, optional): a slightly overestimated rank of :math:`X`.
            Default value is :math:`q=min(6,N,M)`.
        center (bool, optional): if True, center the input tensor.
            Default value is True.
        name (str, optional): Name for the operation (optional, default is None).
            For more information, please refer to :ref:`api_guide_Name`.

    Returns:
        - Tensor U, is N x q matrix.
        - Tensor S, is a vector with length q.
        - Tensor V, is M x q matrix.

        tuple (U, S, V): which is the nearly optimal approximation of a singular value decomposition of a centered matrix :math:`X`.

    Examples:
        .. code-block:: python

            import paddle

            x = paddle.randn((5, 5), dtype='float64')
            U, S, V = paddle.linalg.pca_lowrank(x)
            print(U)
            # Tensor(shape=[5, 5], dtype=float64, place=Place(gpu:0), stop_gradient=True,
            #        [[ 0.41057070,  0.40364287,  0.59099574, -0.34529432,  0.44721360],
            #         [-0.30243321,  0.55670611, -0.15025419,  0.61321785,  0.44721360],
            #         [ 0.57427340, -0.15936327, -0.66414981, -0.06097905,  0.44721360],
            #         [-0.63897516, -0.09968973, -0.17298615, -0.59316819,  0.44721360],
            #         [-0.04343573, -0.70129598,  0.39639442,  0.38622370,  0.44721360]])

            print(S)
            # Tensor(shape=[5], dtype=float64, place=Place(gpu:0), stop_gradient=True,
            #        [3.33724265, 2.57573259, 1.69479048, 0.68069312, 0.00000000])

            print(V)
            # Tensor(shape=[5, 5], dtype=float64, place=Place(gpu:0), stop_gradient=True,
            #        [[ 0.09800724, -0.32627008, -0.23593953,  0.81840445,  0.39810690],
            #         [-0.60100303,  0.63741176, -0.01953663,  0.09023999,  0.47326173],
            #         [ 0.25073864, -0.21305240, -0.32662950, -0.54786156,  0.69634740],
            #         [ 0.33057205,  0.48282641, -0.75998527,  0.06744040, -0.27472705],
            #         [ 0.67604895,  0.45688227,  0.50959437,  0.13179682,  0.23908071]])
    """

    def conjugate(x):
        if x.is_complex():
            return x.conj()
        return x

    def transpose(x):
        shape = x.shape
        perm = list(range(0, len(shape)))
        perm = perm[:-2] + [perm[-1]] + [perm[-2]]
        return paddle.transpose(x, perm)

    def transjugate(x):
        return conjugate(transpose(x))

    def get_approximate_basis(x, q, niter=2, M=None):
        niter = 2 if niter is None else niter
        m, n = x.shape[-2:]
        qr = paddle.linalg.qr

        R = paddle.randn((n, q), dtype=x.dtype)

        A_t = transpose(x)
        A_H = conjugate(A_t)
        if M is None:
            Q = qr(paddle.matmul(x, R))[0]
            for i in range(niter):
                Q = qr(paddle.matmul(A_H, Q))[0]
                Q = qr(paddle.matmul(x, Q))[0]
        else:
            M_H = transjugate(M)
            Q = qr(paddle.matmul(x, R) - paddle.matmul(M, R))[0]
            for i in range(niter):
                Q = qr(paddle.matmul(A_H, Q) - paddle.matmul(M_H, Q))[0]
                Q = qr(paddle.matmul(x, Q) - paddle.matmul(M, Q))[0]

        return Q

    def svd_lowrank(x, q=6, niter=2, M=None):
        q = 6 if q is None else q
        m, n = x.shape[-2:]
        if M is None:
            M_t = None
        else:
            M_t = transpose(M)
        A_t = transpose(x)

        if m < n or n > q:
            Q = get_approximate_basis(A_t, q, niter=niter, M=M_t)
            Q_c = conjugate(Q)
            if M is None:
                B_t = paddle.matmul(x, Q_c)
            else:
                B_t = paddle.matmul(x, Q_c) - paddle.matmul(M, Q_c)
            assert B_t.shape[-2] == m, (B_t.shape, m)
            assert B_t.shape[-1] == q, (B_t.shape, q)
            assert B_t.shape[-1] <= B_t.shape[-2], B_t.shape
            U, S, Vh = paddle.linalg.svd(B_t, full_matrices=False)
            V = transjugate(Vh)
            V = Q.matmul(V)
        else:
            Q = get_approximate_basis(x, q, niter=niter, M=M)
            Q_c = conjugate(Q)
            if M is None:
                B = paddle.matmul(A_t, Q_c)
            else:
                B = paddle.matmul(A_t, Q_c) - paddle.matmul(M_t, Q_c)
            B_t = transpose(B)
            assert B_t.shape[-2] == q, (B_t.shape, q)
            assert B_t.shape[-1] == n, (B_t.shape, n)
            assert B_t.shape[-1] <= B_t.shape[-2], B_t.shape
            U, S, Vh = paddle.linalg.svd(B_t, full_matrices=False)
            V = transjugate(Vh)
            U = Q.matmul(U)

        return U, S, V

    if not paddle.is_tensor(x):
        raise ValueError(f'Input must be tensor, but got {type(x)}')

    (m, n) = x.shape[-2:]

    if q is None:
        q = min(6, m, n)
    elif not (q >= 0 and q <= min(m, n)):
        raise ValueError(
            'q(={}) must be non-negative integer'
            ' and not greater than min(m, n)={}'.format(q, min(m, n))
        )
    if not (niter >= 0):
        raise ValueError(f'niter(={niter}) must be non-negative integer')

    if not center:
        return svd_lowrank(x, q, niter=niter, M=None)

    C = x.mean(axis=-2, keepdim=True)
    return svd_lowrank(x - C, q, niter=niter, M=None)


2123 2124
def matrix_power(x, n, name=None):
    r"""
2125

2126
    Computes the n-th power of a square matrix or a batch of square matrices.
2127

2128 2129 2130 2131 2132
    Let :math:`X` be a sqaure matrix or a batch of square matrices, :math:`n` be
    an exponent, the equation should be:

    .. math::
        Out = X ^ {n}
2133

2134 2135
    Specifically,

2136
    - If `n > 0`, it returns the matrix or a batch of matrices raised to the power of `n`.
2137

2138 2139
    - If `n = 0`, it returns the identity matrix or a batch of identity matrices.

2140
    - If `n < 0`, it returns the inverse of each matrix (if invertible) raised to the power of `abs(n)`.
2141 2142 2143 2144 2145 2146

    Args:
        x (Tensor): A square matrix or a batch of square matrices to be raised
            to power `n`. Its shape should be `[*, M, M]`, where `*` is zero or
            more batch dimensions. Its data type should be float32 or float64.
        n (int): The exponent. It can be any positive, negative integer or zero.
2147
        name (str, optional): Name for the operation (optional, default is None).
2148 2149 2150
            For more information, please refer to :ref:`api_guide_Name`.

    Returns:
2151 2152
        - Tensor, The n-th power of the matrix (or the batch of matrices) `x`. Its
          data type should be the same as that of `x`.
2153 2154 2155 2156 2157 2158 2159 2160 2161

    Examples:
        .. code-block:: python

            import paddle

            x = paddle.to_tensor([[1, 2, 3],
                                  [1, 4, 9],
                                  [1, 8, 27]], dtype='float64')
2162
            print(paddle.linalg.matrix_power(x, 2))
2163 2164 2165 2166
            # [[6.  , 34. , 102.],
            #  [14. , 90. , 282.],
            #  [36. , 250., 804.]]

2167
            print(paddle.linalg.matrix_power(x, 0))
2168 2169 2170 2171
            # [[1., 0., 0.],
            #  [0., 1., 0.],
            #  [0., 0., 1.]]

2172
            print(paddle.linalg.matrix_power(x, -2))
2173 2174 2175 2176
            # [[ 12.91666667, -12.75000000,  2.83333333 ],
            #  [-7.66666667 ,  8.         , -1.83333333 ],
            #  [ 1.80555556 , -1.91666667 ,  0.44444444 ]]
    """
2177
    if in_dynamic_mode():
2178
        return _C_ops.matrix_power(x, n)
2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192
    else:
        check_variable_and_dtype(
            x, 'dtype', ['float32', 'float64'], 'matrix_power'
        )
        check_type(n, 'n', int, 'matrix_power')
        helper = LayerHelper('matrix_power', **locals())
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
        helper.append_op(
            type='matrix_power',
            inputs={'X': x},
            outputs={'Out': out},
            attrs={'n': n},
        )
        return out
2193 2194


2195 2196 2197 2198 2199 2200 2201
def qr(x, mode="reduced", name=None):
    r"""
    Computes the QR decomposition of one matrix or batches of matrice (backward is unsupported now).

    Args:
        x (Tensor): The input tensor. Its shape should be `[..., M, N]`,
            where ... is zero or more batch dimensions. M and N can be arbitrary
2202 2203
            positive number. The data type of x should be float32 or float64.
        mode (str, optional): A flag to control the behavior of qr, the default is "reduced".
2204
            Suppose x's shape is `[..., M, N]` and denoting `K = min(M, N)`:
2205
            If mode = "reduced", qr op will return reduced Q and R matrices,
2206
            which means Q's shape is `[..., M, K]` and R's shape is `[..., K, N]`.
2207
            If mode = "complete", qr op will return complete Q and R matrices,
2208 2209 2210 2211 2212
            which means Q's shape is `[..., M, M]` and R's shape is `[..., M, N]`.
            If mode = "r", qr op will only return reduced R matrix, which means
            R's shape is `[..., K, N]`.
        name (str, optional): Name for the operation (optional, default is None).
            For more information, please refer to :ref:`api_guide_Name`.
2213

2214
    Returns:
2215
        If mode = "reduced" or mode = "complete", qr will return a two tensor-tuple, which represents Q and R.
2216
        If mode = "r", qr will return a tensor which represents R.
2217 2218

    Examples:
2219 2220
        .. code-block:: python

2221
            import paddle
2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233

            x = paddle.to_tensor([[1.0, 2.0], [3.0, 4.0], [5.0, 6.0]]).astype('float64')
            q, r = paddle.linalg.qr(x)
            print (q)
            print (r)

            # Q = [[-0.16903085,  0.89708523],
            #      [-0.50709255,  0.27602622],
            #      [-0.84515425, -0.34503278]])

            # R = [[-5.91607978, -7.43735744],
            #      [ 0.        ,  0.82807867]])
2234 2235

            # one can verify : X = Q * R ;
2236
    """
2237
    if in_dynamic_mode():
2238
        q, r = _C_ops.qr(x, mode)
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        if mode == "r":
            return r
        else:
            return q, r
2243 2244 2245 2246 2247 2248
    else:
        check_variable_and_dtype(x, 'dtype', ['float32', 'float64'], 'qr')
        check_type(mode, 'mode', str, 'qr')
        helper = LayerHelper('qr', **locals())
        q = helper.create_variable_for_type_inference(dtype=x.dtype)
        r = helper.create_variable_for_type_inference(dtype=x.dtype)
2249
        attrs = {}
2250 2251 2252 2253
        attrs['mode'] = mode
        helper.append_op(
            type='qr', inputs={'X': [x]}, outputs={'Q': q, 'R': r}, attrs=attrs
        )
2254 2255 2256 2257 2258 2259
        if mode == "r":
            return r
        else:
            return q, r


2260 2261
def lu(x, pivot=True, get_infos=False, name=None):
    r"""
2262
    Computes the LU factorization of an N-D(N>=2) matrix x.
2263

2264
    Returns the LU factorization(inplace x) and Pivots. low triangular matrix L and
2265 2266 2267 2268
    upper triangular matrix U are combined to a single LU matrix.

    Pivoting is done if pivot is set to True.
    P mat can be get by pivots:
2269 2270

    .. code-block:: text
2271

2272 2273 2274 2275
        ones = eye(rows) #eye matrix of rank rows
        for i in range(cols):
            swap(ones[i], ones[pivots[i]])
        return ones
2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286

    Args:

        X (Tensor): the tensor to factor of N-dimensions(N>=2).

        pivot (bool, optional): controls whether pivoting is done. Default: True.

        get_infos (bool, optional): if set to True, returns an info IntTensor. Default: False.

        name (str, optional): Name for the operation (optional, default is None).
            For more information, please refer to :ref:`api_guide_Name`.
2287

2288
    Returns:
2289
        factorization (Tensor), LU matrix, the factorization of input X.
2290

2291 2292 2293
        pivots (IntTensor), the pivots of size(∗(N-2), min(m,n)). `pivots` stores all the
        intermediate transpositions of rows. The final permutation `perm` could be
        reconstructed by this, details refer to upper example.
2294

2295 2296 2297
        infos (IntTensor, optional), if `get_infos` is `True`, this is a tensor of size (∗(N-2))
        where non-zero values indicate whether factorization for the matrix or each minibatch
        has succeeded or failed.
2298

2299 2300

    Examples:
2301 2302
        .. code-block:: python

2303
            import paddle
2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318

            x = paddle.to_tensor([[1.0, 2.0], [3.0, 4.0], [5.0, 6.0]]).astype('float64')
            lu,p,info = paddle.linalg.lu(x, get_infos=True)

            # >>> lu:
            # Tensor(shape=[3, 2], dtype=float64, place=CUDAPlace(0), stop_gradient=True,
            #    [[5.        , 6.        ],
            #        [0.20000000, 0.80000000],
            #        [0.60000000, 0.50000000]])
            # >>> p
            # Tensor(shape=[2], dtype=int32, place=CUDAPlace(0), stop_gradient=True,
            #    [3, 3])
            # >>> info
            # Tensor(shape=[], dtype=int32, place=CUDAPlace(0), stop_gradient=True,
            #    0)
2319

2320 2321 2322 2323 2324 2325
            P,L,U = paddle.linalg.lu_unpack(lu,p)

            # >>> P
            # (Tensor(shape=[3, 3], dtype=float64, place=CUDAPlace(0), stop_gradient=True,
            # [[0., 1., 0.],
            # [0., 0., 1.],
2326
            # [1., 0., 0.]]),
2327 2328 2329 2330
            # >>> L
            # Tensor(shape=[3, 2], dtype=float64, place=CUDAPlace(0), stop_gradient=True,
            # [[1.        , 0.        ],
            # [0.20000000, 1.        ],
2331
            # [0.60000000, 0.50000000]]),
2332 2333 2334 2335 2336
            # >>> U
            # Tensor(shape=[2, 2], dtype=float64, place=CUDAPlace(0), stop_gradient=True,
            # [[5.        , 6.        ],
            # [0.        , 0.80000000]]))

2337 2338

            # one can verify : X = P @ L @ U ;
2339
    """
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2340

2341
    if in_dynamic_mode():
2342
        lu, p, info = _C_ops.lu(x, pivot)
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    else:
        check_variable_and_dtype(x, 'dtype', ['float32', 'float64'], 'lu')
        helper = LayerHelper('lu', **locals())
        lu = helper.create_variable_for_type_inference(dtype=x.dtype)
        p = helper.create_variable_for_type_inference(dtype='int')
        info = helper.create_variable_for_type_inference(dtype='int')
2349
        attrs = {}
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        attrs['pivot'] = pivot
2351 2352 2353 2354 2355 2356
        helper.append_op(
            type='lu',
            inputs={'X': x},
            outputs={'Out': lu, 'Pivots': p, 'Infos': info},
            attrs=attrs,
        )
2357 2358 2359 2360 2361 2362 2363 2364
    if get_infos:
        return lu, p, info
    else:
        return lu, p


def lu_unpack(x, y, unpack_ludata=True, unpack_pivots=True, name=None):
    r"""
2365
    Unpack L U and P to single matrix tensor .
2366 2367 2368
    unpack L and U matrix from LU, unpack permutation matrix P from Pivtos .

    P mat can be get by pivots:
2369 2370

    .. code-block:: text
2371

2372 2373 2374
        ones = eye(rows) #eye matrix of rank rows
        for i in range(cols):
            swap(ones[i], ones[pivots[i]])
2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387


    Args:
        x (Tensor): The LU tensor get from paddle.linalg.lu, which is combined by L and U.

        y (Tensor): Pivots get from paddle.linalg.lu.

        unpack_ludata (bool,optional): whether to unpack L and U from x. Default: True.

        unpack_pivots (bool, optional): whether to unpack permutation matrix P from Pivtos. Default: True.

        name (str, optional): Name for the operation (optional, default is None).
            For more information, please refer to :ref:`api_guide_Name`.
2388

2389
    Returns:
2390
        P (Tensor), Permutation matrix P of lu factorization.
2391

2392
        L (Tensor), The lower triangular matrix tensor of lu factorization.
2393

2394
        U (Tensor), The upper triangular matrix tensor of lu factorization.
2395

2396 2397

    Examples:
2398 2399
        .. code-block:: python

2400
            import paddle
2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415

            x = paddle.to_tensor([[1.0, 2.0], [3.0, 4.0], [5.0, 6.0]]).astype('float64')
            lu,p,info = paddle.linalg.lu(x, get_infos=True)

            # >>> lu:
            # Tensor(shape=[3, 2], dtype=float64, place=CUDAPlace(0), stop_gradient=True,
            #    [[5.        , 6.        ],
            #        [0.20000000, 0.80000000],
            #        [0.60000000, 0.50000000]])
            # >>> p
            # Tensor(shape=[2], dtype=int32, place=CUDAPlace(0), stop_gradient=True,
            #    [3, 3])
            # >>> info
            # Tensor(shape=[], dtype=int32, place=CUDAPlace(0), stop_gradient=True,
            #    0)
2416

2417 2418 2419 2420 2421 2422
            P,L,U = paddle.linalg.lu_unpack(lu,p)

            # >>> P
            # (Tensor(shape=[3, 3], dtype=float64, place=CUDAPlace(0), stop_gradient=True,
            # [[0., 1., 0.],
            # [0., 0., 1.],
2423
            # [1., 0., 0.]]),
2424 2425 2426 2427
            # >>> L
            # Tensor(shape=[3, 2], dtype=float64, place=CUDAPlace(0), stop_gradient=True,
            # [[1.        , 0.        ],
            # [0.20000000, 1.        ],
2428
            # [0.60000000, 0.50000000]]),
2429 2430 2431 2432 2433
            # >>> U
            # Tensor(shape=[2, 2], dtype=float64, place=CUDAPlace(0), stop_gradient=True,
            # [[5.        , 6.        ],
            # [0.        , 0.80000000]]))

2434
            # one can verify : X = P @ L @ U ;
2435 2436
    """

2437
    if in_dynamic_mode():
2438
        P, L, U = _C_ops.lu_unpack(x, y, unpack_ludata, unpack_pivots)
2439
        return P, L, U
2440 2441 2442
    else:
        check_variable_and_dtype(
            x, 'dtype', ['float32', 'float64'], 'lu_unpack'
2443
        )
2444 2445 2446 2447
        helper = LayerHelper('lu_unpack', **locals())
        p = helper.create_variable_for_type_inference(dtype=x.dtype)
        l = helper.create_variable_for_type_inference(dtype=x.dtype)
        u = helper.create_variable_for_type_inference(dtype=x.dtype)
2448

2449
        attrs = {}
2450 2451 2452 2453 2454 2455 2456 2457 2458
        attrs['unpack_ludata'] = unpack_ludata
        attrs['unpack_pivots'] = unpack_pivots
        helper.append_op(
            type='lu_unpack',
            inputs={'X': x, 'Pivots': y},
            outputs={'Pmat': p, 'L': l, 'U': u},
            attrs=attrs,
        )
        return p, l, u
2459 2460


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2461 2462
def eig(x, name=None):
    """
2463
    Performs the eigenvalue decomposition of a square matrix or a batch of square matrices.
L
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2464

2465 2466 2467 2468 2469 2470
    Note:
        - If the matrix is a Hermitian or a real symmetric matrix, please use :ref:`paddle.linalg.eigh` instead, which is much faster.
        - If only eigenvalues is needed, please use :ref:`paddle.linalg.eigvals` instead.
        - If the matrix is of any shape, please use :ref:`paddle.linalg.svd`.
        - This API is only supported on CPU device.
        - The output datatype is always complex for both real and complex input.
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2471 2472 2473 2474

    Args:
        x (Tensor): A tensor with shape math:`[*, N, N]`, The data type of the x should be one of ``float32``,
            ``float64``, ``compplex64`` or ``complex128``.
2475
        name (str, optional): The default value is `None`. Normally there is no need for user to set
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2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488
            this property. For more information, please refer to :ref:`api_guide_Name`.

    Returns:
        Eigenvalues(Tensors): A tensor with shape math:`[*, N]` refers to the eigen values.
        Eigenvectors(Tensors): A tensor with shape math:`[*, N, N]` refers to the eigen vectors.

    Examples:
        .. code-block:: python

            import paddle

            paddle.device.set_device("cpu")

2489
            x = paddle.to_tensor([[1.6707249, 7.2249975, 6.5045543],
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2490
                               [9.956216,  8.749598,  6.066444 ],
2491
                               [4.4251957, 1.7983172, 0.370647 ]])
L
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2492
            w, v = paddle.linalg.eig(x)
2493
            print(v)
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2494 2495 2496 2497 2498 2499 2500 2501
            # Tensor(shape=[3, 3], dtype=complex128, place=CPUPlace, stop_gradient=False,
            #       [[(-0.5061363550800655+0j) , (-0.7971760990842826+0j) ,
            #         (0.18518077798279986+0j)],
            #        [(-0.8308237755993192+0j) ,  (0.3463813401919749+0j) ,
            #         (-0.6837005269141947+0j) ],
            #        [(-0.23142567697893396+0j),  (0.4944999840400175+0j) ,
            #         (0.7058765252952796+0j) ]])

2502
            print(w)
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2503 2504 2505 2506
            # Tensor(shape=[3], dtype=complex128, place=CPUPlace, stop_gradient=False,
            #       [ (16.50471283351188+0j)  , (-5.5034820550763515+0j) ,
            #         (-0.21026087843552282+0j)])
    """
2507

2508
    if in_dynamic_mode():
2509
        return _C_ops.eig(x)
2510 2511 2512 2513 2514
    else:
        check_variable_and_dtype(
            x, 'X', ['float32', 'float64', 'complex64', 'complex128'], 'eig'
        )
        helper = LayerHelper('eig', **locals())
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2515

2516 2517
        w = helper.create_variable_for_type_inference(x.dtype)
        v = helper.create_variable_for_type_inference(x.dtype)
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2518

2519 2520 2521
        inputs = {'X': x}
        outputs = {'Eigenvalues': w, 'Eigenvectors': v}
        helper.append_op(type='eig', inputs=inputs, outputs=outputs)
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2522

2523
        return w, v
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2524 2525


2526 2527 2528
def eigvals(x, name=None):
    """
    Compute the eigenvalues of one or more general matrices.
2529 2530 2531

    Warning:
        The gradient kernel of this operator does not yet developed.
2532 2533 2534 2535
        If you need back propagation through this operator, please replace it with paddle.linalg.eig.

    Args:
        x (Tensor): A square matrix or a batch of square matrices whose eigenvalues will be computed.
2536
            Its shape should be `[*, M, M]`, where `*` is zero or more batch dimensions.
2537
            Its data type should be float32, float64, complex64, or complex128.
2538
        name (str, optional): Name for the operation (optional, default is None).
2539
            For more information, please refer to :ref:`api_guide_Name`.
2540

2541
    Returns:
2542 2543
        Tensor, A tensor containing the unsorted eigenvalues which has the same batch
        dimensions with `x`. The eigenvalues are complex-valued even when `x` is real.
2544 2545 2546 2547 2548

    Examples:
        .. code-block:: python

            import paddle
2549

2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564
            paddle.set_device("cpu")
            paddle.seed(1234)

            x = paddle.rand(shape=[3, 3], dtype='float64')
            # [[0.02773777, 0.93004224, 0.06911496],
            #  [0.24831591, 0.45733623, 0.07717843],
            #  [0.48016702, 0.14235102, 0.42620817]])

            print(paddle.linalg.eigvals(x))
            # [(-0.27078833542132674+0j), (0.29962280156230725+0j), (0.8824477020120244+0j)] #complex128
    """

    x_shape = list(x.shape)
    if len(x_shape) < 2:
        raise ValueError(
2565 2566 2567 2568
            "The dimension of Input(x) should be at least 2, but received x's dimention = {}, x's shape = {}".format(
                len(x_shape), x_shape
            )
        )
2569 2570 2571

    if x_shape[-1] != x_shape[-2]:
        raise ValueError(
2572 2573 2574 2575
            "The last two dimensions of Input(x) should be equal, but received x's shape = {}".format(
                x_shape
            )
        )
2576

2577
    if in_dynamic_mode():
2578
        return _C_ops.eigvals(x)
2579
    else:
2580 2581 2582 2583 2584 2585
        check_variable_and_dtype(
            x,
            'dtype',
            ['float32', 'float64', 'complex64', 'complex128'],
            'eigvals',
        )
2586 2587 2588 2589
        helper = LayerHelper('eigvals', **locals())
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
        helper.append_op(type='eigvals', inputs={'X': x}, outputs={'Out': out})
        return out
2590 2591


2592 2593 2594 2595
def multi_dot(x, name=None):
    """
    Multi_dot is an operator that calculates multiple matrix multiplications.

2596
    Supports inputs of float16(only GPU support), float32 and float64 dtypes. This function does not
2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632
    support batched inputs.

    The input tensor in [x] must be 2-D except for the first and last can be 1-D.
    If the first tensor is a 1-D vector of shape(n, ) it is treated as row vector
    of shape(1, n), similarly if the last tensor is a 1D vector of shape(n, ), it
    is treated as a column vector of shape(n, 1).

    If the first and last tensor are 2-D matrix, then the output is also 2-D matrix,
    otherwise the output is a 1-D vector.

    Multi_dot will select the lowest cost multiplication order for calculation. The
    cost of multiplying two matrices with shapes (a, b) and (b, c) is a * b * c.
    Given matrices A, B, C with shapes (20, 5), (5, 100), (100, 10) respectively,
    we can calculate the cost of different multiplication orders as follows:
    - Cost((AB)C) = 20x5x100 + 20x100x10 = 30000
    - Cost(A(BC)) = 5x100x10 + 20x5x10 = 6000

    In this case, multiplying B and C first, then multiply A, which is 5 times faster
    than sequential calculation.

    Args:
        x ([Tensor]): The input tensors which is a list Tensor.
        name(str|None): A name for this layer(optional). If set None, the layer
            will be named automatically.

    Returns:
        Tensor: The output Tensor.


    Examples:

    .. code-block:: python

        import paddle

        # A * B
2633 2634
        A = paddle.rand([3, 4])
        B = paddle.rand([4, 5])
2635
        out = paddle.linalg.multi_dot([A, B])
2636
        print(out.shape)
2637 2638 2639
        # [3, 5]

        # A * B * C
2640 2641 2642
        A = paddle.rand([10, 5])
        B = paddle.rand([5, 8])
        C = paddle.rand([8, 7])
2643
        out = paddle.linalg.multi_dot([A, B, C])
2644
        print(out.shape)
2645 2646 2647
        # [10, 7]

    """
2648
    if in_dynamic_mode():
2649
        return _C_ops.multi_dot(x)
2650 2651 2652 2653 2654 2655
    else:
        check_type(x, 'x', (list, tuple), 'multi_dot')
        for id, item in enumerate(x):
            check_variable_and_dtype(
                item,
                'x[' + str(id) + ']',
2656
                ['float16', 'float32', 'float64', 'uint16'],
2657 2658 2659 2660 2661 2662
                'multi_dot',
            )
            if item.dtype != x[0].dtype:
                raise TypeError(
                    "All the Tensors in the input must have the same data type."
                )
2663

2664 2665 2666 2667 2668
        helper = LayerHelper('multi_dot', **locals())
        dtype = helper.input_dtype(input_param_name='x')
        out = helper.create_variable_for_type_inference(dtype)
        helper.append_op(
            type='multi_dot', inputs={"X": x}, outputs={"Out": out}
2669
        )
2670
        return out
2671 2672 2673 2674


def eigh(x, UPLO='L', name=None):
    """
2675
    Compute the eigenvalues and eigenvectors of a
2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686
    complex Hermitian (conjugate symmetric) or a real symmetric matrix.

    Args:
        x (Tensor): A tensor with shape :math:`[*, N, N]` , The data type of the input Tensor x
            should be one of float32, float64, complex64, complex128.
        UPLO(str, optional): (string, default 'L'), 'L' represents the lower triangular matrix,
                        "'U' represents the upper triangular matrix.".
        name(str, optional): The default value is None.  Normally there is no need for user to set this
            property.  For more information, please refer to :ref:`api_guide_Name`.

    Returns:
2687 2688 2689 2690
        - out_value(Tensor):  A Tensor with shape [*, N] and data type of float32 and float64.
            The eigenvalues of eigh op.
        - out_vector(Tensor): A Tensor with shape [*, N, N] and data type of float32,float64,
            complex64 and complex128. The eigenvectors of eigh op.
2691 2692 2693 2694 2695 2696

    Examples:
        .. code-block:: python

            import paddle

2697
            x = paddle.to_tensor([[1, -2j], [2j, 5]])
2698
            out_value, out_vector = paddle.linalg.eigh(x, UPLO='L')
2699 2700 2701 2702 2703 2704 2705
            print(out_value)
            #[0.17157288, 5.82842712]
            print(out_vector)
            #[(-0.9238795325112867+0j), (-0.3826834323650898+0j)],
            #[ 0.3826834323650898j    , -0.9238795325112867j    ]]

    """
2706
    if in_dynamic_mode():
2707
        return _C_ops.eigh(x, UPLO)
2708
    else:
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        def __check_input(x, UPLO):
            x_shape = list(x.shape)
            if len(x.shape) < 2:
                raise ValueError(
                    "Input(input) only support >=2 tensor, but received "
                    "length of Input(input) is %s." % len(x.shape)
                )
            if x_shape[-1] != x_shape[-2]:
                raise ValueError(
                    "The input matrix must be batches of square matrices. But received x's dimention: {}".format(
                        x_shape
                    )
                )
            if UPLO != 'L' and UPLO != 'U':
                raise ValueError(
2725
                    f"UPLO must be L or U. But received UPLO is: {UPLO}"
2726
                )
2727

2728
        __check_input(x, UPLO)
2729

2730 2731 2732 2733 2734 2735 2736
        helper = LayerHelper('eigh', **locals())
        check_variable_and_dtype(
            x,
            'dtype',
            ['float32', 'float64', 'complex64', 'complex128'],
            'eigh',
        )
2737

2738 2739
        out_value = helper.create_variable_for_type_inference(dtype=x.dtype)
        out_vector = helper.create_variable_for_type_inference(dtype=x.dtype)
2740

2741 2742 2743 2744 2745 2746 2747
        helper.append_op(
            type='eigh',
            inputs={'X': x},
            outputs={'Eigenvalues': out_value, 'Eigenvectors': out_vector},
            attrs={'UPLO': UPLO},
        )
        return out_value, out_vector
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def pinv(x, rcond=1e-15, hermitian=False, name=None):
    r"""
2752
    Calculate pseudo inverse via SVD(singular value decomposition)
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    of one matrix or batches of regular matrix.

    .. math::

        if hermitian == False:
            x = u * s * vt  (SVD)
            out = v * 1/s * ut
        else:
            x = u * s * ut  (eigh)
            out = u * 1/s * u.conj().transpose(-2,-1)
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    If x is hermitian or symmetric matrix, svd will be replaced with eigh.

    Args:
2767 2768 2769
        x(Tensor): The input tensor. Its shape should be (*, m, n)
            where * is zero or more batch dimensions. m and n can be
            arbitraty positive number. The data type of x should be
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            float32 or float64 or complex64 or complex128. When data
            type is complex64 or cpmplex128, hermitian should be set
            True.

2774
        rcond(Tensor, optional): the tolerance value to determine
2775
            when is a singular value zero. Default:1e-15.
2776 2777

        hermitian(bool, optional): indicates whether x is Hermitian
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            if complex or symmetric if real. Default: False.
2779 2780

        name(str|None): A name for this layer(optional). If set None,
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            the layer will be named automatically.
2782

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    Returns:
2784
        Tensor: The tensor with same data type with x. it represents
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        pseudo inverse of x. Its shape should be (*, n, m).
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    Examples:
        .. code-block:: python

            import paddle

            x = paddle.arange(15).reshape((3, 5)).astype('float64')
            input = paddle.to_tensor(x)
            out = paddle.linalg.pinv(input)
            print(input)
            print(out)

            # input:
            # [[0. , 1. , 2. , 3. , 4. ],
            # [5. , 6. , 7. , 8. , 9. ],
            # [10., 11., 12., 13., 14.]]

            # out:
            # [[-0.22666667, -0.06666667,  0.09333333],
            # [-0.12333333, -0.03333333,  0.05666667],
            # [-0.02000000,  0.00000000,  0.02000000],
            # [ 0.08333333,  0.03333333, -0.01666667],
            # [ 0.18666667,  0.06666667, -0.05333333]]

            # one can verify : x * out * x = x ;
            # or              out * x * out = x ;
    """
2813
    if in_dynamic_mode():
2814 2815
        if not hermitian:
            # combine svd and matmul op
2816 2817
            u, s, vt = _C_ops.svd(x, False)
            max_singular_val = _C_ops.max(s, [-1], True)
2818 2819 2820 2821
            rcond = paddle.to_tensor(rcond, dtype=x.dtype)
            cutoff = rcond * max_singular_val
            y = float('inf')
            y = paddle.to_tensor(y, dtype=x.dtype)
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            singular = paddle.where(s > cutoff, 1 / s, 1 / y)
2824
            st = _C_ops.unsqueeze(singular, [-2])
2825 2826 2827

            dims = list(range(len(vt.shape)))
            perm = dims[:-2] + [dims[-1]] + [dims[-2]]
2828
            v = _C_ops.transpose(vt, perm)
2829 2830

            out_1 = v * st
2831
            out_2 = _C_ops.matmul(out_1, u, False, True)
2832 2833 2834
            return out_2
        else:
            # combine eigh and matmul op
2835
            s, u = _C_ops.eigh(x, 'UPLO')
2836
            s_abs = paddle.abs(s)
2837
            max_singular_val = _C_ops.max(s_abs, [-1], True)
2838 2839 2840 2841 2842
            rcond = paddle.to_tensor(rcond, dtype=s.dtype)
            cutoff = rcond * max_singular_val
            y = float('inf')
            y = paddle.to_tensor(y, dtype=s.dtype)

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            singular = paddle.where(s_abs > cutoff, 1 / s, 1 / y)
2844
            st = _C_ops.unsqueeze(singular, [-2])
2845 2846

            out_1 = u * st
2847 2848
            u_conj = _C_ops.conj(u)
            out_2 = _C_ops.matmul(out_1, u_conj, False, True)
2849
            return out_2
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    else:
        if not hermitian:
            helper = LayerHelper('pinv', **locals())
            dtype = x.dtype
            check_variable_and_dtype(x, 'x', ['float32', 'float64'], 'pinv')

            u = helper.create_variable_for_type_inference(dtype)
            s = helper.create_variable_for_type_inference(dtype)
            vt = helper.create_variable_for_type_inference(dtype)
            helper.append_op(
                type='svd',
                inputs={'X': [x]},
2862
                outputs={'U': u, 'VH': vt, 'S': s},
2863 2864
                attrs={'full_matrices': False},
            )
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            max_singular_val = helper.create_variable_for_type_inference(dtype)
2867 2868 2869 2870 2871 2872
            helper.append_op(
                type='reduce_max',
                inputs={'X': s},
                outputs={'Out': max_singular_val},
                attrs={'dim': [-1], 'keep_dim': True, 'reduce_all': False},
            )
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2874
            rcond = full(shape=[1], fill_value=rcond, dtype=dtype)
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            cutoff = rcond * max_singular_val
            y = float('inf')
2877
            y = full(shape=[1], fill_value=y, dtype=dtype)
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            singular = paddle.where(s > cutoff, 1 / s, 1 / y)
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            st = helper.create_variable_for_type_inference(dtype=dtype)
            st_shape = helper.create_variable_for_type_inference(dtype=dtype)
2883 2884 2885 2886 2887 2888
            helper.append_op(
                type='unsqueeze2',
                inputs={'X': singular},
                attrs={'axes': [-2]},
                outputs={'Out': st, 'XShape': st_shape},
            )
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            dims = list(range(len(vt.shape)))
            perm = dims[:-2] + [dims[-1]] + [dims[-2]]
            v = helper.create_variable_for_type_inference(dtype)
            v_shape = helper.create_variable_for_type_inference(dtype)
2894 2895 2896 2897 2898 2899
            helper.append_op(
                type='transpose2',
                inputs={'X': [vt]},
                outputs={'Out': [v], 'XShape': [v_shape]},
                attrs={'axis': perm},
            )
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            out_1 = helper.create_variable_for_type_inference(dtype)
2902 2903 2904 2905 2906 2907
            helper.append_op(
                type='elementwise_mul',
                inputs={'X': v, 'Y': st},
                outputs={'Out': out_1},
                attrs={'axis': -1, 'use_mkldnn': False},
            )
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            out_1 = helper.append_activation(out_1)

            out_2 = helper.create_variable_for_type_inference(dtype)
            helper.append_op(
                type='matmul_v2',
2913
                inputs={'X': out_1, 'Y': u},
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                outputs={'Out': out_2},
2915
                attrs={'trans_x': False, 'trans_y': True},
2916
            )
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            return out_2
        else:
            helper = LayerHelper('pinv', **locals())
            dtype = x.dtype
            check_variable_and_dtype(
2922 2923 2924 2925 2926
                x,
                'dtype',
                ['float32', 'float64', 'complex64', 'complex128'],
                'pinv',
            )
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            if dtype == paddle.complex128:
                s_type = 'float64'
            elif dtype == paddle.complex64:
                s_type = 'float32'
            else:
                s_type = dtype

            u = helper.create_variable_for_type_inference(dtype)
            s = helper.create_variable_for_type_inference(s_type)
2937 2938 2939 2940 2941 2942
            helper.append_op(
                type='eigh',
                inputs={'X': x},
                outputs={'Eigenvalues': s, 'Eigenvectors': u},
                attrs={'UPLO': 'L'},
            )
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            s_abs = helper.create_variable_for_type_inference(s_type)
2944 2945 2946
            helper.append_op(
                type='abs', inputs={'X': s}, outputs={'Out': s_abs}
            )
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            max_singular_val = helper.create_variable_for_type_inference(s_type)
2948 2949 2950 2951 2952 2953
            helper.append_op(
                type='reduce_max',
                inputs={'X': s_abs},
                outputs={'Out': max_singular_val},
                attrs={'dim': [-1], 'keep_dim': True, 'reduce_all': False},
            )
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2955
            rcond = full(shape=[1], fill_value=rcond, dtype=s_type)
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            cutoff = rcond * max_singular_val
            y = float('inf')
2958
            y = full(shape=[1], fill_value=y, dtype=s_type)
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            singular = paddle.where(s_abs > cutoff, 1 / s, 1 / y)
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            st = helper.create_variable_for_type_inference(dtype=s_type)
            st_shape = helper.create_variable_for_type_inference(dtype=s_type)
2964 2965 2966 2967 2968 2969
            helper.append_op(
                type='unsqueeze2',
                inputs={'X': singular},
                attrs={'axes': [-2]},
                outputs={'Out': st, 'XShape': st_shape},
            )
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            out_1 = helper.create_variable_for_type_inference(dtype)
2972 2973 2974 2975 2976 2977
            helper.append_op(
                type='elementwise_mul',
                inputs={'X': u, 'Y': st},
                outputs={'Out': out_1},
                attrs={'axis': -1, 'use_mkldnn': False},
            )
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2978 2979 2980
            out_1 = helper.append_activation(out_1)

            u_conj = helper.create_variable_for_type_inference(dtype)
2981 2982 2983
            helper.append_op(
                type='conj', inputs={'X': u}, outputs={'Out': [u_conj]}
            )
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            out_2 = helper.create_variable_for_type_inference(dtype)
            helper.append_op(
                type='matmul_v2',
2988
                inputs={'X': out_1, 'Y': u_conj},
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                outputs={'Out': out_2},
2990
                attrs={'trans_x': False, 'trans_y': True},
2991
            )
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            return out_2
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2993 2994 2995 2996


def solve(x, y, name=None):
    r"""
2997

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2998
    Computes the solution of a square system of linear equations with a unique solution for input 'X' and 'Y'.
2999
    Let :math:`X` be a sqaure matrix or a batch of square matrices, :math:`Y` be
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    a vector/matrix or a batch of vectors/matrices, the equation should be:
3001

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3002 3003
    .. math::
        Out = X^-1 * Y
3004 3005

    Specifically, this system of linear equations has one solution if and only if input 'X' is invertible.
3006

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    Args:
3008
        x (Tensor): A square matrix or a batch of square matrices. Its shape should be ``[*, M, M]``, where ``*`` is zero or
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            more batch dimensions. Its data type should be float32 or float64.
3010
        y (Tensor): A vector/matrix or a batch of vectors/matrices. Its shape should be ``[*, M, K]``, where ``*`` is zero or
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            more batch dimensions. Its data type should be float32 or float64.
3012
        name(str, optional): Name for the operation (optional, default is None).
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            For more information, please refer to :ref:`api_guide_Name`.
3014

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    Returns:
3016
        Tensor: The solution of a square system of linear equations with a unique solution for input 'x' and 'y'.
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        Its data type should be the same as that of `x`.
3018

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    Examples:
3020

3021
        .. code-block:: python
3022

3023 3024 3025
            # a square system of linear equations:
            # 2*X0 + X1 = 9
            # X0 + 2*X1 = 8
3026

3027 3028 3029 3030 3031
            import paddle

            x = paddle.to_tensor([[3, 1],[1, 2]], dtype="float64")
            y = paddle.to_tensor([9, 8], dtype="float64")
            out = paddle.linalg.solve(x, y)
3032

3033 3034
            print(out)
            # [2., 3.])
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    """
3036
    if in_dynamic_mode():
3037
        return _C_ops.solve(x, y)
3038 3039 3040 3041 3042 3043
    else:
        inputs = {"X": [x], "Y": [y]}
        helper = LayerHelper("solve", **locals())
        check_variable_and_dtype(x, 'x', ['float32', 'float64'], 'solve')
        check_variable_and_dtype(y, 'y', ['float32', 'float64'], 'solve')
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
3044

3045 3046 3047 3048
        helper.append_op(
            type="solve", inputs={"X": x, "Y": y}, outputs={"Out": out}
        )
        return out
3049 3050


3051 3052 3053
def triangular_solve(
    x, y, upper=True, transpose=False, unitriangular=False, name=None
):
3054
    r"""
3055 3056
    Computes the solution of a system of equations with a triangular coefficient.  `x` is coefficient matrix
    `y` is multiple right-hand sides of equations.
3057

3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069
    Input `x` and `y` is 2D matrices or batches of 2D matrices. If the inputs are batches, the outputs is also
    batches.

    Equations can be described as:

    .. math::
        x * Out = y

    Solution of Equations is:

    .. math::
        Out = x ^ {-1} * y
3070 3071 3072 3073

    Args:
        x (Tensor): The input triangular coefficient matrix. Its shape should be `[*, M, M]`, where `*` is zero or
            more batch dimensions. Its data type should be float32 or float64.
3074
        y (Tensor): Multiple right-hand sides of system of equations. Its shape should be `[*, M, K]`, where `*` is
3075
            zero or more batch dimensions. Its data type should be float32 or float64.
3076
        upper (bool, optional): Whether to solve the upper-triangular system of equations (default) or the lower-triangular
3077 3078
            system of equations. Default: True.
        transpose (bool, optional): whether `x` should be transposed before calculation. Default: False.
3079
        unitriangular (bool, optional): whether `x` is unit triangular. If True, the diagonal elements of `x` are assumed
3080 3081 3082 3083 3084 3085 3086 3087
            to be 1 and not referenced from `x` . Default: False.
        name(str, optional): Name for the operation (optional, default is None).
            For more information, please refer to :ref:`api_guide_Name`.

    Returns:
        Tensor: The solution of the system of equations. Its data type should be the same as that of `x`.

    Examples:
3088
        .. code-block:: python
3089

3090 3091 3092 3093
            # a square system of linear equations:
            # x1 +   x2  +   x3 = 0
            #      2*x2  +   x3 = -9
            #               -x3 = 5
3094

3095 3096 3097 3098 3099 3100
            import paddle
            x = paddle.to_tensor([[1, 1, 1],
                                  [0, 2, 1],
                                  [0, 0,-1]], dtype="float64")
            y = paddle.to_tensor([[0], [-9], [5]], dtype="float64")
            out = paddle.linalg.triangular_solve(x, y, upper=True)
3101

3102 3103
            print(out)
            # [7, -2, -5]
3104
    """
3105
    if in_dynamic_mode():
3106
        return _C_ops.triangular_solve(x, y, upper, transpose, unitriangular)
3107 3108 3109 3110 3111
    else:
        inputs = {"X": [x], "Y": [y]}
        helper = LayerHelper("triangular_solve", **locals())
        check_variable_and_dtype(
            x, 'x', ['float32', 'float64'], 'triangular_solve'
3112
        )
3113 3114 3115 3116
        check_variable_and_dtype(
            y, 'y', ['float32', 'float64'], 'triangular_solve'
        )
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
3117

3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128
        helper.append_op(
            type='triangular_solve',
            inputs={'X': x, 'Y': y},
            outputs={'Out': out},
            attrs={
                'upper': upper,
                'transpose': transpose,
                'unitriangular': unitriangular,
            },
        )
        return out
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def cholesky_solve(x, y, upper=False, name=None):
    r"""
    Solves a linear system of equations A @ X = B, given A's Cholesky factor matrix u and  matrix B.

    Input `x` and `y` is 2D matrices or batches of 2D matrices. If the inputs are batches, the outputs
    is also batches.

    Args:
3139
        x (Tensor): Multiple right-hand sides of system of equations. Its shape should be `[*, M, K]`, where `*` is
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            zero or more batch dimensions. Its data type should be float32 or float64.
3141 3142
        y (Tensor): The input matrix which is upper or lower triangular Cholesky factor of square matrix A. Its shape should be `[*, M, M]`, where `*` is zero or
            more batch dimensions. Its data type should be float32 or float64.
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        upper (bool, optional): whether to consider the Cholesky factor as a lower or upper triangular matrix. Default: False.
        name(str, optional): Name for the operation (optional, default is None).
            For more information, please refer to :ref:`api_guide_Name`.

    Returns:
        Tensor: The solution of the system of equations. Its data type is the same as that of `x`.

    Examples:
3151
        .. code-block:: python
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3152

3153
            import paddle
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3155 3156 3157 3158 3159
            u = paddle.to_tensor([[1, 1, 1],
                                    [0, 2, 1],
                                    [0, 0,-1]], dtype="float64")
            b = paddle.to_tensor([[0], [-9], [5]], dtype="float64")
            out = paddle.linalg.cholesky_solve(b, u, upper=True)
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            print(out)
            # [-2.5, -7, 9.5]
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    """
3164
    if in_dynamic_mode():
3165
        return _C_ops.cholesky_solve(x, y, upper)
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    else:
        helper = LayerHelper("cholesky_solve", **locals())
        check_variable_and_dtype(
            x, 'x', ['float32', 'float64'], 'cholesky_solve'
        )
        check_variable_and_dtype(
            y, 'y', ['float32', 'float64'], 'cholesky_solve'
        )
        out = helper.create_variable_for_type_inference(dtype=x.dtype)
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        helper.append_op(
            type='cholesky_solve',
            inputs={'X': x, 'Y': y},
            outputs={'Out': out},
            attrs={'upper': upper},
        )
        return out
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3185 3186
def eigvalsh(x, UPLO='L', name=None):
    """
3187
    Computes the eigenvalues of a
3188 3189 3190
    complex Hermitian (conjugate symmetric) or a real symmetric matrix.

    Args:
3191
        x (Tensor): A tensor with shape :math:`[*, M, M]` , where * is zero or greater batch dimension. The data type of the input Tensor x
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            should be one of float32, float64, complex64, complex128.
        UPLO(str, optional): Lower triangular part of a (‘L’, default) or the upper triangular part (‘U’).
        name(str, optional): The default value is None.  Normally there is no need for user to set this
            property.  For more information, please refer to :ref:`api_guide_Name`.

    Returns:
        Tensor: The tensor eigenvalues in ascending order.

    Examples:
        .. code-block:: python

            import paddle

3205
            x = paddle.to_tensor([[1, -2j], [2j, 5]])
3206 3207
            out_value = paddle.eigvalsh(x, UPLO='L')
            print(out_value)
3208 3209
            # Tensor(shape=[2], dtype=float32, place=Place(cpu), stop_gradient=True,
            #        [0.17157286, 5.82842731])
3210
    """
3211
    if in_dynamic_mode():
3212
        values, _ = _C_ops.eigvalsh(x, UPLO, x.stop_gradient)
3213
        return values
3214
    else:
3215

3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230
        def __check_input(x, UPLO):
            x_shape = list(x.shape)
            if len(x.shape) < 2:
                raise ValueError(
                    "Input(input) only support >=2 tensor, but received "
                    "length of Input(input) is %s." % len(x.shape)
                )
            if x_shape[-1] != x_shape[-2]:
                raise ValueError(
                    "The input matrix must be batches of square matrices. But received x's dimention: {}".format(
                        x_shape
                    )
                )
            if UPLO != 'L' and UPLO != 'U':
                raise ValueError(
3231
                    f"UPLO must be L or U. But received UPLO is: {UPLO}"
3232
                )
3233

3234
        __check_input(x, UPLO)
3235

3236 3237 3238 3239 3240 3241 3242
        helper = LayerHelper('eigvalsh', **locals())
        check_variable_and_dtype(
            x,
            'dtype',
            ['float32', 'float64', 'complex64', 'complex128'],
            'eigvalsh',
        )
3243

3244 3245
        out_value = helper.create_variable_for_type_inference(dtype=x.dtype)
        out_vector = helper.create_variable_for_type_inference(dtype=x.dtype)
3246

3247 3248 3249 3250 3251 3252 3253 3254
        is_test = x.stop_gradient
        helper.append_op(
            type='eigvalsh',
            inputs={'X': x},
            outputs={'Eigenvalues': out_value, 'Eigenvectors': out_vector},
            attrs={'UPLO': UPLO, 'is_test': is_test},
        )
        return out_value
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3257 3258 3259 3260 3261 3262 3263 3264
def lstsq(x, y, rcond=None, driver=None, name=None):
    """
    Computes a solution to
    the least squares problem of a system of linear equations.

    Args:
        x (Tensor): A tensor with shape ``(*, M, N)`` , the data type of the input Tensor ``x``
            should be one of float32, float64.
3265
        y (Tensor): A tensor with shape ``(*, M, K)`` , the data type of the input Tensor ``y``
3266
            should be one of float32, float64.
3267 3268
        rcond(float, optional): The default value is None. A float pointing number used to determine
            the effective rank of ``x``. If ``rcond`` is None, it will be set to max(M, N) times the
3269
            machine precision of x_dtype.
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        driver(str, optional): The default value is None. The name of LAPACK method to be used. For
            CPU inputs the valid values are ‘gels’, ‘gelsy’, ‘gelsd, ‘gelss’. For CUDA input, the only
            valid driver is ‘gels’. If ``driver`` is None, ‘gelsy’ is used for CPU inputs and ‘gels’
3273
            for CUDA inputs.
3274
        name(str, optional): The default value is None. Normally there is no need for user to set
3275 3276 3277
            this property. For more information, please refer to :ref:`api_guide_Name`.

    Returns:
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        Tuple: A tuple of 4 Tensors which is (``solution``, ``residuals``, ``rank``, ``singular_values``).
        ``solution`` is a tensor with shape ``(*, N, K)``, meaning the least squares solution. ``residuals``
        is a tensor with shape ``(*, K)``, meaning the squared residuals of the solutions, which is computed
        when M > N and every matrix in ``x`` is full-rank, otherwise return an empty tensor. ``rank`` is a tensor
        with shape ``(*)``, meaning the ranks of the matrices in ``x``, which is computed when ``driver`` in
        (‘gelsy’, ‘gelsd’, ‘gelss’), otherwise return an empty tensor. ``singular_values`` is a tensor with
        shape ``(*, min(M, N))``, meaning singular values of the matrices in ``x``, which is computed when
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        ``driver`` in (‘gelsd’, ‘gelss’), otherwise return an empty tensor.

    Examples:
        .. code-block:: python

            import paddle

            paddle.set_device("cpu")
            x = paddle.to_tensor([[1, 3], [3, 2], [5, 6.]])
            y = paddle.to_tensor([[3, 4, 6], [5, 3, 4], [1, 2, 1.]])
            results = paddle.linalg.lstsq(x, y, driver="gelsd")
            print(results[0])
            # [[ 0.78350395, -0.22165027, -0.62371236],
            # [-0.11340097,  0.78866047,  1.14948535]]
            print(results[1])
            # [19.81443405, 10.43814468, 30.56185532])
            print(results[2])
            # 2
            print(results[3])
            # [9.03455734, 1.54167950]

            x = paddle.to_tensor([[10, 2, 3], [3, 10, 5], [5, 6, 12.]])
            y = paddle.to_tensor([[4, 2, 9], [2, 0, 3], [2, 5, 3.]])
            results = paddle.linalg.lstsq(x, y, driver="gels")
            print(results[0])
            # [[ 0.39386186,  0.10230173,  0.93606132],
            # [ 0.10741687, -0.29028133,  0.11892585],
            # [-0.05115091,  0.51918161, -0.19948854]]
            print(results[1])
            # []
    """
    device = paddle.get_device()
3317 3318 3319
    if device == "cpu":
        if driver not in (None, "gels", "gelss", "gelsd", "gelsy"):
            raise ValueError(
3320 3321 3322 3323
                "Only support valid driver is 'gels', 'gelss', 'gelsd', 'gelsy' or None for CPU inputs. But got {}".format(
                    driver
                )
            )
3324 3325 3326 3327
        driver = "gelsy" if driver is None else driver
    elif "gpu" in device:
        if driver not in (None, "gels"):
            raise ValueError(
3328 3329 3330 3331
                "Only support valid driver is 'gels' or None for CUDA inputs. But got {}".format(
                    driver
                )
            )
3332 3333 3334 3335
        driver = "gels" if driver is None else driver
    else:
        raise RuntimeError("Only support lstsq api for CPU or CUDA device.")

3336
    if not (x.dtype == y.dtype and x.dtype in (paddle.float32, paddle.float64)):
3337 3338 3339 3340
        raise ValueError(
            "Only support x and y have the same dtype such as 'float32' and 'float64'."
        )

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    if x.ndim < 2:
        raise ValueError(
            f"The shape of x should be (*, M, N), but received ndim is [{x.ndim} < 2]"
        )

    if y.ndim < 2:
        raise ValueError(
            f"The shape of y should be (*, M, K), but received ndim is [{y.ndim} < 2]"
        )

    if x.shape[-2] != y.shape[-2]:
        raise ValueError(
            f"x with shape (*, M = {x.shape[-2]}, N) and y with shape (*, M = {y.shape[-2]}, K) should have same M."
        )

3356 3357 3358 3359 3360 3361
    if rcond is None:
        if x.dtype == paddle.float32:
            rcond = 1e-7 * max(x.shape[-2], x.shape[-1])
        elif x.dtype == paddle.float64:
            rcond = 1e-15 * max(x.shape[-2], x.shape[-1])

3362
    if in_dynamic_mode():
3363 3364 3365
        solution, residuals, rank, singular_values = _C_ops.lstsq(
            x, y, rcond, driver
        )
3366 3367 3368 3369 3370 3371 3372
        if driver == "gels":
            rank = paddle.empty(shape=[0], dtype=paddle.int32)
            singular_values = paddle.empty(shape=[0], dtype=x.dtype)
        elif driver == "gelsy":
            singular_values = paddle.empty(shape=[0], dtype=x.dtype)

        return solution, residuals, rank, singular_values
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    else:
        helper = LayerHelper('lstsq', **locals())
        check_variable_and_dtype(
            x,
            'dtype',
            ['float32', 'float64', 'complex64', 'complex128'],
            'lstsq',
        )
        check_variable_and_dtype(
            y,
            'dtype',
            ['float32', 'float64', 'complex64', 'complex128'],
            'lstsq',
        )
3387

3388 3389 3390 3391 3392 3393
        solution = helper.create_variable_for_type_inference(dtype=x.dtype)
        residuals = helper.create_variable_for_type_inference(dtype=x.dtype)
        rank = helper.create_variable_for_type_inference(dtype=paddle.int32)
        singular_values = helper.create_variable_for_type_inference(
            dtype=x.dtype
        )
3394

3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405
        helper.append_op(
            type='lstsq',
            inputs={'X': x, 'Y': y},
            outputs={
                'Solution': solution,
                'Residuals': residuals,
                'Rank': rank,
                'SingularValues': singular_values,
            },
            attrs={'rcond': rcond, 'driver': driver},
        )
3406

3407 3408 3409 3410 3411 3412 3413 3414 3415
        if driver == "gels":
            rank = paddle.static.data(name='rank', shape=[0])
            singular_values = paddle.static.data(
                name='singular_values', shape=[0]
            )
        elif driver == "gelsy":
            singular_values = paddle.static.data(
                name='singular_values', shape=[0]
            )
3416

3417
        return solution, residuals, rank, singular_values
3418 3419 3420 3421


def corrcoef(x, rowvar=True, name=None):
    """
3422

3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445
    A correlation coefficient matrix indicate the correlation of each pair variables in the input matrix.
    For example, for an N-dimensional samples X=[x1,x2,…xN]T, then the correlation coefficient matrix
    element Rij is the correlation of xi and xj. The element Rii is the covariance of xi itself.

    The relationship between the correlation coefficient matrix `R` and the
    covariance matrix `C`, is

    .. math:: R_{ij} = \\frac{ C_{ij} } { \\sqrt{ C_{ii} * C_{jj} } }

    The values of `R` are between -1 and 1.

    Parameters:

        x(Tensor): A N-D(N<=2) Tensor containing multiple variables and observations. By default, each row of x represents a variable. Also see rowvar below.
        rowvar(Bool, optional): If rowvar is True (default), then each row represents a variable, with observations in the columns. Default: True.
        name(str, optional): Name of the output. Default is None. It's used to print debug info for developers. Details: :ref:`api_guide_Name`.

    Returns:

        The correlation coefficient matrix of the variables.

    Examples:
        .. code-block:: python
3446

3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460
            import paddle

            xt = paddle.rand((3,4))
            print(paddle.linalg.corrcoef(xt))

            # Tensor(shape=[3, 3], dtype=float32, place=Place(cpu), stop_gradient=True,
            # [[ 1.        , -0.73702252,  0.66228950],
            # [-0.73702258,  1.        , -0.77104872],
            # [ 0.66228974, -0.77104825,  1.        ]])

    """
    if len(x.shape) > 2 or len(x.shape) < 1:
        raise ValueError(
            "Input(x) only support N-D (1<=N<=2) tensor in corrcoef, but received "
3461 3462
            "length of Input(input) is %s." % len(x.shape)
        )
3463 3464 3465
    check_variable_and_dtype(x, 'dtype', ['float32', 'float64'], 'corrcoef')

    c = cov(x, rowvar)
3466
    if c.ndim == 0:
3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480
        # scalar covariance
        # nan if incorrect value (nan, inf, 0), 1 otherwise
        return c / c

    d = paddle.diag(c)

    if paddle.is_complex(d):
        d = d.real()
    stddev = paddle.sqrt(d)
    c /= stddev[:, None]
    c /= stddev[None, :]

    # Clip to [-1, 1].  This does not guarantee
    if paddle.is_complex(c):
3481 3482 3483
        return paddle.complex(
            paddle.clip(c.real(), -1, 1), paddle.clip(c.imag(), -1, 1)
        )
3484 3485 3486 3487
    else:
        c = paddle.clip(c, -1, 1)

    return c
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def cdist(
    x, y, p=2.0, compute_mode="use_mm_for_euclid_dist_if_necessary", name=None
):
    r"""

    Compute the p-norm distance between each pair of the two collections of inputs.

    This function is equivalent to `scipy.spatial.distance.cdist(input,'minkowski', p=p)`
    if :math:`p \in (0, \infty)`. When :math:`p = 0` it is equivalent to `scipy.spatial.distance.cdist(input, 'hamming') * M`.
    When :math:`p = \infty`, the closest scipy function is `scipy.spatial.distance.cdist(xn, lambda x, y: np.abs(x - y).max())`.

    Args:
        x (Tensor): A tensor with shape :math:`B \times P \times M`.
        y (Tensor): A tensor with shape :math:`B \times R \times M`.
        p (float, optional): The value for the p-norm distance to calculate between each vector pair. Default: :math:`2.0`.
        compute_mode (str, optional): The mode for compute distance.

            - ``use_mm_for_euclid_dist_if_necessary`` , for p = 2.0 and (P > 25 or R > 25), it will use matrix multiplication to calculate euclid distance if possible.
            - ``use_mm_for_euclid_dist`` , for p = 2.0, it will use matrix multiplication to calculate euclid distance.
            - ``donot_use_mm_for_euclid_dist`` , it will not use matrix multiplication to calculate euclid distance.

            Default: ``use_mm_for_euclid_dist_if_necessary``.
        name (str, optional): For details, please refer to :ref:`api_guide_Name`. Generally, no setting is required. Default: None.

    Returns:
        Tensor, the dtype is same as input tensor.

        If x has shape :math:`B \times P \times M` and y has shape :math:`B \times R \times M` then
        the output will have shape :math:`B \times P \times R`.

    Examples:
        .. code-block:: python

            import paddle
            x = paddle.to_tensor([[0.9041,  0.0196], [-0.3108, -2.4423], [-0.4821,  1.059]], dtype=paddle.float32)
            y = paddle.to_tensor([[-2.1763, -0.4713], [-0.6986,  1.3702]], dtype=paddle.float32)
            distance = paddle.cdist(x, y)
            print(distance)
            # Tensor(shape=[3, 2], dtype=float32, place=Place(gpu:0), stop_gradient=True,
            # [[3.1193, 2.0959], [2.7138, 3.8322], [2.2830, 0.3791]])
    """

    check_variable_and_dtype(x, 'x', ('float32', 'float64'), 'cdist')
    check_variable_and_dtype(y, 'y', ('float32', 'float64'), 'cdist')
    check_type(p, 'p', (float, int), 'cdist')

    if compute_mode not in [
        'use_mm_for_euclid_dist_if_necessary',
        'use_mm_for_euclid_dist',
        'donot_use_mm_for_euclid_dist',
    ]:
        raise ValueError(
            "The compute_mode should be 'use_mm_for_euclid_dist_if_necessary', "
            "'use_mm_for_euclid_dist' or 'donot_use_mm_for_euclid_dist', "
            "but received compute_mode is %s." % compute_mode
        )

    mode = 0
    if compute_mode == 'use_mm_for_euclid_dist_if_necessary':
        mode = 0
    elif compute_mode == 'use_mm_for_euclid_dist':
        mode = 1
    elif compute_mode == 'donot_use_mm_for_euclid_dist':
        mode = 2

    x_shape = list(x.shape)
    assert len(x_shape) >= 2, (
        "The x must be at least 2-dimensional, "
        "But received Input x's dimensional is %s.\n" % len(x_shape)
    )
    y_shape = list(y.shape)
    assert len(y_shape) >= 2, (
        "The y must be at least 2-dimensional, "
        "But received Input y's dimensional is %s.\n" % len(y_shape)
    )
    assert x_shape[-1] == y_shape[-1], (
        "The x and y must have same last dimension, "
        "But received Input x's last dimension is {}, "
        "Input y's last dimension is {}.\n".format(x_shape[-1], y_shape[-1])
    )
    assert p >= 0, (
        "The p must be greater than or equal to 0, "
        "But received p is %s.\n" % p
    )

    r1 = x.shape[-2]
    r2 = y.shape[-2]
    c1 = x.shape[-1]

    p = float(p)

    if r1 == 0 or r2 == 0:
        return paddle.empty((r1, r2), dtype=x.dtype)

    if c1 == 0:
        return paddle.zeros((r1, r2), dtype=x.dtype)

    if p == 2.0 and (mode == 1 or (mode == 0 and (r1 > 25 or r2 > 25))):
        x_norm = paddle.sum(x.pow(2), axis=-1, keepdim=True)
        y_norm = paddle.sum(y.pow(2), axis=-1, keepdim=True)
        y_transposed = paddle.transpose(
            y, perm=[*range(y.ndim - 2), y.ndim - 1, y.ndim - 2]
        )
        y_norm_transposed = paddle.transpose(
            y_norm,
            perm=[*range(y_norm.ndim - 2), y_norm.ndim - 1, y_norm.ndim - 2],
        )
        res = paddle.matmul(x, y_transposed) * -2 + y_norm_transposed + x_norm
        res = paddle.clip(res, min=0.0).sqrt()
        return res

    return paddle.linalg.norm(
        x[..., None, :] - y[..., None, :, :], p=p, axis=-1
    )