Cherry pick: add reshape in paddle.complex (#24210)

* add reshape in paddle.complex, test=develop
* fix typos in paddle.complex.kron's comment, fix unittest, test=release-2.0

python/paddle/complex/tensor/__init__.py

@@ -13,6 +13,9 @@
 # limitations under the License.
 
 from . import math
+from . import manipulation
 from .math import *
+from .manipulation import *
 
 __all__ = math.__all__ + []
+__all__ += manipulation.__all__

python/paddle/complex/tensor/manipulation.py

+#  Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserve.
+#
+# 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.
+
+from paddle.common_ops_import import *
+from ..helper import is_complex, is_real, complex_variable_exists
+from ...fluid.framework import ComplexVariable
+from ...fluid import layers
+
+__all__ = ['reshape', ]
+
+
+def reshape(x, shape, inplace=False, name=None):
+    """
+    To change the shape of ``x`` without changing its data.
+
+    There are some tricks when specifying the target shape.
+
+    1. -1 means the value of this dimension is inferred from the total element
+    number of x and remaining dimensions. Thus one and only one dimension can
+    be set -1.
+
+    2. 0 means the actual dimension value is going to be copied from the
+    corresponding dimension of x. The index of 0s in shape can not exceed
+    the dimension of x.
+
+    Here are some examples to explain it.
+
+    1. Given a 3-D tensor x with a shape [2, 4, 6], and the target shape
+    is [6, 8], the reshape operator will transform x into a 2-D tensor with
+    shape [6, 8] and leaving x's data unchanged.
+
+    2. Given a 3-D tensor x with a shape [2, 4, 6], and the target shape
+    specified is [2, 3, -1, 2], the reshape operator will transform x into a
+    4-D tensor with shape [2, 3, 4, 2] and leaving x's data unchanged. In this
+    case, one dimension of the target shape is set to -1, the value of this
+    dimension is inferred from the total element number of x and remaining
+    dimensions.
+
+    3. Given a 3-D tensor x with a shape [2, 4, 6], and the target shape
+    is [-1, 0, 3, 2], the reshape operator will transform x into a 4-D tensor
+    with shape [2, 4, 3, 2] and leaving x's data unchanged. In this case,
+    besides -1, 0 means the actual dimension value is going to be copied from
+    the corresponding dimension of x.
+
+    Args:
+        x(ComplexVariable): the input. A ``Tensor`` or ``LoDTensor`` , data 
+            type: ``complex64`` or ``complex128``.
+        shape(list|tuple|Variable): target shape. At most one dimension of 
+            the target shape can be -1. If ``shape`` is a list or tuple, the 
+            elements of it should be integers or Tensors with shape [1] and 
+            data type ``int32``. If ``shape`` is an Variable, it should be 
+            an 1-D Tensor of data type ``int32``.
+        inplace(bool, optional): If ``inplace`` is True, the output of 
+            ``reshape`` is the same ComplexVariable as the input. Otherwise, 
+            the input and output of ``reshape`` are different 
+            ComplexVariables. Defaults to False. Note that if ``x``is more 
+            than one OPs' input, ``inplace`` must be 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:
+        ComplexVariable: A ``Tensor`` or ``LoDTensor``. The data type is same as ``x``. It is a new ComplexVariable if ``inplace`` is ``False``, otherwise it is ``x``.
+        
+    Raises:
+        ValueError: If more than one elements of ``shape`` is -1.
+        ValueError: If the element of ``shape`` is 0, the corresponding dimension should be less than or equal to the dimension of ``x``.
+        ValueError: If the elements in ``shape`` is negative except -1.
+
+    Examples:
+        .. code-block:: python
+
+            import paddle.fluid as fluid
+            import paddle.complex as cpx
+            import paddle.fluid.dygraph as dg
+            import numpy as np
+            
+            x_np = np.random.randn(2, 3, 4) + 1j * np.random.randn(2, 3, 4)
+            
+            place = fluid.CPUPlace()
+            with dg.guard(place):
+                x_var = dg.to_variable(x_np)
+                y_var = cpx.reshape(x_var, (2, -1))
+                y_np = y_var.numpy()
+                print(y_np.shape)
+                # (2, 12)
+"""
+    complex_variable_exists([x], "reshape")
+    if inplace:
+        x.real = fluid.layers.reshape(x.real, shape, inplace=inplace, name=name)
+        x.imag = fluid.layers.reshape(x.imag, shape, inplace=inplace, name=name)
+        return x
+    out_real = fluid.layers.reshape(x.real, shape, inplace=inplace, name=name)
+    out_imag = fluid.layers.reshape(x.imag, shape, inplace=inplace, name=name)
+    return ComplexVariable(out_real, out_imag)

python/paddle/fluid/tests/unittests/test_complex_reshape.py

+# 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.
+
+import paddle.fluid as fluid
+import paddle.complex as cpx
+import paddle.fluid.dygraph as dg
+import numpy as np
+import unittest
+
+
+class TestComplexReshape(unittest.TestCase):
+    def test_case1(self):
+        x_np = np.random.randn(2, 3, 4) + 1j * np.random.randn(2, 3, 4)
+        shape = (2, -1)
+
+        place = fluid.CPUPlace()
+        with dg.guard(place):
+            x_var = dg.to_variable(x_np)
+            y_var = cpx.reshape(x_var, shape)
+            y_np = y_var.numpy()
+
+        np.testing.assert_allclose(np.reshape(x_np, shape), y_np)
+
+    def test_case2(self):
+        x_np = np.random.randn(2, 3, 4) + 1j * np.random.randn(2, 3, 4)
+        shape = (0, -1)
+        shape_ = (2, 12)
+
+        place = fluid.CUDAPlace(0) if fluid.is_compiled_with_cuda(
+        ) else fluid.CPUPlace()
+        with dg.guard(place):
+            x_var = dg.to_variable(x_np)
+            y_var = cpx.reshape(x_var, shape, inplace=True)
+            y_np = y_var.numpy()
+
+        np.testing.assert_allclose(np.reshape(x_np, shape_), y_np)
+
+
+if __name__ == "__main__":
+    unittest.main()