Merge branch 'develop' of https://github.com/PaddlePaddle/Paddle into dev_add_doc

paddle/fluid/operators/activation_op.cc

@@ -112,7 +112,7 @@ $$out = \frac{1}{1 + e^{-x}}$$
 __attribute__((unused)) constexpr char LogSigmoidDoc[] = R"DOC(
 Logsigmoid Activation Operator
 
-$$out = \log \frac{1}{1 + e^{-x}}$$
+$$out = \\log \\frac{1}{1 + e^{-x}}$$
 
 )DOC";
 

paddle/fluid/operators/detection/box_coder_op.cc

@@ -106,23 +106,36 @@ class BoxCoderOpMaker : public framework::OpProtoAndCheckerMaker {
               "and M represents the number of deocded boxes.");
 
     AddComment(R"DOC(
-Bounding Box Coder Operator.
+
+Bounding Box Coder.
+
 Encode/Decode the target bounding box with the priorbox information.
+
 The Encoding schema described below:
-ox = (tx - px) / pw / pxv
-oy = (ty - py) / ph / pyv
-ow = log(abs(tw / pw)) / pwv 
-oh = log(abs(th / ph)) / phv 
+
+    ox = (tx - px) / pw / pxv
+
+    oy = (ty - py) / ph / pyv
+
+    ow = log(abs(tw / pw)) / pwv 
+
+    oh = log(abs(th / ph)) / phv 
+
 The Decoding schema described below:
-ox = (pw * pxv * tx * + px) - tw / 2
-oy = (ph * pyv * ty * + py) - th / 2
-ow = exp(pwv * tw) * pw + tw / 2
-oh = exp(phv * th) * ph + th / 2
-where tx, ty, tw, th denote the target box's center coordinates, width and
-height respectively. Similarly, px, py, pw, ph denote the priorbox's(anchor)
-center coordinates, width and height. pxv, pyv, pwv, phv denote the variance
-of the priorbox and ox, oy, ow, oh denote the encoded/decoded coordinates,
-width and height.
+
+    ox = (pw * pxv * tx * + px) - tw / 2
+
+    oy = (ph * pyv * ty * + py) - th / 2
+
+    ow = exp(pwv * tw) * pw + tw / 2
+
+    oh = exp(phv * th) * ph + th / 2
+
+where `tx`, `ty`, `tw`, `th` denote the target box's center coordinates, width
+and height respectively. Similarly, `px`, `py`, `pw`, `ph` denote the
+priorbox's (anchor) center coordinates, width and height. `pxv`, `pyv`, `pwv`,
+`phv` denote the variance of the priorbox and `ox`, `oy`, `ow`, `oh` denote the
+encoded/decoded coordinates, width and height.
 )DOC");
   }
 };

paddle/fluid/operators/gaussian_random_batch_size_like_op.cc

@@ -36,11 +36,12 @@ class GaussianRandomBatchSizeLikeOpMaker : public BatchSizeLikeOpMaker {
   void Apply() override {
     AddAttr<float>("mean",
                    "(float, default 0.0) "
-                   "mean of random tensor.")
+                   "The mean (or center) of the gaussian distribution.")
         .SetDefault(.0f);
     AddAttr<float>("std",
                    "(float, default 1.0) "
-                   "std of random tensor.")
+                   "The standard deviation (std, or spread) of the "
+                   "gaussian distribution.")
         .SetDefault(1.0f);
     AddAttr<int>("seed",
                  "(int, default 0) "
@@ -55,9 +56,11 @@ class GaussianRandomBatchSizeLikeOpMaker : public BatchSizeLikeOpMaker {
         .SetDefault(framework::proto::VarType::FP32);
 
     AddComment(R"DOC(
-GaussianRandom Operator.
 
 Used to initialize tensors with gaussian random generator.
+The defalut mean of the distribution is 0. and defalut standard
+deviation (std) of the distribution is 1.. Uers can set mean and std
+by input arguments.
 )DOC");
   }
 };

python/paddle/fluid/initializer.py

@@ -15,11 +15,13 @@
 import framework
 import numpy as np
 import contextlib
+from framework import convert_np_dtype_to_dtype_
+from core import VarDesc
 
 __all__ = [
-    'Constant', 'Uniform', 'Normal', 'Xavier', 'force_init_on_cpu',
+    'Constant', 'Uniform', 'Normal', 'Xavier', 'Bilinear', 'force_init_on_cpu',
     'init_on_cpu', 'ConstantInitializer', 'UniformInitializer',
-    'NormalInitializer', 'XavierInitializer'
+    'NormalInitializer', 'XavierInitializer', 'BilinearInitializer'
 ]
 
 _force_init_on_cpu_ = False
@@ -422,6 +424,101 @@ class MSRAInitializer(Initializer):
         return op
 
 
+class BilinearInitializer(Initializer):
+    """Implements the bilinear initializer.
+
+    This initializer can be used in transposed convolution operator to
+    act as upsampling. Users can upsample a feature map with shape of
+    (B, C, H, W) by any integer factor. The usage is:
+  
+    >>>  factor = 2
+    >>>  w_attr = ParamAttr(learning_rate=0., regularizer=L2Decay(0.),
+    >>>                     initializer=Bilinear())
+    >>>  conv_up = fluid.layers.conv2d_transpose(
+    >>>      input,
+    >>>      num_filters=C,
+    >>>      output_size=None,
+    >>>      filter_size=2 * factor - factor % 2,
+    >>>      padding=ceil((factor - 1) / 2.),
+    >>>      stride=factor,
+    >>>      groups=C,
+    >>>      param_attr=w_attr,
+    >>>      bias_attr=False)
+
+
+    Where, `num_filters=C` and `groups=C` means this is channel-wise tranposed
+    convolution. The filter shape will be (C, 1, K, K) where K is `filer_size`,
+    This initializer will set a (K, K) interpolation kernel for every channel
+    of the filter identically. The resulting shape of the output feature map
+    will be (B, C, factor * H, factor * W). Note that the learning rate and the
+    weight decay are set to 0 in order to keep coefficient values of bilinear
+    interpolation unchanged during training. 
+    """
+
+    def __init__(self):
+        """Constructor for BilinearInitializer.
+        """
+        super(BilinearInitializer, self).__init__()
+
+    def __call__(self, var, block):
+        """Add biliear initialization ops for a variable
+
+        Args:
+            var (Variable): Variable that needs to be initialized.
+            block (Block): The block in which initialization ops should
+                           be added.
+
+        Returns:
+            the initialization op
+
+        Raises:
+            ValueError: If type of `var` and `block` is not right.
+                        If the shape of `var` size is not 4 and
+                        var.shape[2] != var.shape[3].
+        """
+        if not isinstance(var, framework.Variable):
+            raise ValueError("var must be framework.Variable.")
+
+        if not isinstance(block, framework.Block):
+            raise ValueError("block must be framework.Block.")
+
+        shape = var.shape
+        if len(shape) != 4:
+            raise ValueError("the length of shape must be 4.")
+        if shape[2] != shape[3]:
+            raise ValueError("shape[2] must be equal to shape[3].")
+
+        weight = np.zeros(np.prod(var.shape), dtype='float32')
+        size = shape[3]
+        # factor
+        f = np.ceil(size / 2.)
+        # center
+        c = (2 * f - 1 - f % 2) / (2. * f)
+        for i in range(np.prod(shape)):
+            x = i % size
+            y = (i / size) % size
+            weight[i] = (1 - abs(x / f - c)) * (1 - abs(y / f - c))
+        weight = np.reshape(weight, shape)
+
+        if var.dtype == VarDesc.VarType.FP32:
+            value_name = "fp32_values"
+            values = [float(v) for v in weight.flat]
+        else:
+            raise ValueError("Unsupported dtype %s", input.dtype)
+        if np.prod(shape) > 1024 * 1024:
+            raise ValueError("The size of input is too big. ")
+        op = block.append_op(
+            type='assign_value',
+            outputs={'Out': [var]},
+            attrs={
+                'dtype': var.dtype,
+                'shape': list(shape),
+                value_name: values
+            })
+        var.op = op
+        return op
+
+
 # We short the class name, since users will use the initializer with the package
 # name. The sample code:
 #
@@ -436,3 +533,4 @@ Uniform = UniformInitializer
 Normal = NormalInitializer
 Xavier = XavierInitializer
 MSRA = MSRAInitializer
+Bilinear = BilinearInitializer

python/paddle/fluid/layers/io.py

@@ -378,16 +378,16 @@ def random_data_generator(low, high, shapes, lod_levels, for_parallel=True):
        Variable: A Reader Variable from which we can get random data.
 
     Examples:
-       .. code-block:: python
 
-         reader = fluid.layers.io.random_data_generator(
-                                          low=0.0,
-                                          high=1.0,
-                                          shapes=[(3,224,224), (1)],
-                                          lod_levels=[0, 0])
+        .. code-block:: python
 
-         # Via the reader, we can use 'read_file' layer to get data:
-         image, label = fluid.layers.io.read_file(reader)
+            reader = fluid.layers.random_data_generator(
+                                             low=0.0,
+                                             high=1.0,
+                                             shapes=[[3,224,224], [1]],
+                                             lod_levels=[0, 0])
+            # Via the reader, we can use 'read_file' layer to get data:
+            image, label = fluid.layers.read_file(reader)
     """
     dtypes = [core.VarDesc.VarType.FP32] * len(shapes)
     shape_concat = []

python/paddle/fluid/layers/nn.py

@@ -364,8 +364,7 @@ def dynamic_lstm(input,
         cell_activation(str): The activation for cell output. Choices = ["sigmoid",
                               "tanh", "relu", "identity"], default "tanh".
         candidate_activation(str): The activation for candidate hidden state.
-                              Choices = ["sigmoid", "tanh",
-                                  "relu", "identity"],
+                              Choices = ["sigmoid", "tanh", "relu", "identity"],
                               default "tanh".
         dtype(str): Data type. Choices = ["float32", "float64"], default "float32".
         name(str|None): A name for this layer(optional). If set None, the layer
@@ -540,27 +539,31 @@ def dynamic_lstmp(input,
         cell_activation(str): The activation for cell output. Choices = ["sigmoid",
                               "tanh", "relu", "identity"], default "tanh".
         candidate_activation(str): The activation for candidate hidden state.
-                              Choices = ["sigmoid", "tanh",
-                                  "relu", "identity"],
+                              Choices = ["sigmoid", "tanh", "relu", "identity"],
                               default "tanh".
         proj_activation(str): The activation for projection output.
-                              Choices = ["sigmoid", "tanh",
-                                  "relu", "identity"],
+                              Choices = ["sigmoid", "tanh", "relu", "identity"],
                               default "tanh".
         dtype(str): Data type. Choices = ["float32", "float64"], default "float32".
         name(str|None): A name for this layer(optional). If set None, the layer
                         will be named automatically.
 
     Returns:
-        tuple: The projection of hidden state, and cell state of LSTMP. The \
-               shape of projection is (T x P), for the cell state which is \
-               (T x D), and both LoD is the same with the `input`.
+        tuple: A tuple of two output variable: the projection of hidden state, \
+               and cell state of LSTMP. The shape of projection is (T x P), \
+               for the cell state which is (T x D), and both LoD is the same \
+               with the `input`.
 
     Examples:
+
         .. code-block:: python
 
+            dict_dim, emb_dim = 128, 64
+            data = fluid.layers.data(name='sequence', shape=[1],
+                                     dtype='int32', lod_level=1)
+            emb = fluid.layers.embedding(input=data, size=[dict_dim, emb_dim])
             hidden_dim, proj_dim = 512, 256
-            fc_out = fluid.layers.fc(input=input_seq, size=hidden_dim * 4,
+            fc_out = fluid.layers.fc(input=emb, size=hidden_dim * 4,
                                      act=None, bias_attr=None)
             proj_out, _ = fluid.layers.dynamic_lstmp(input=fc_out,
                                                      size=hidden_dim * 4,
@@ -626,10 +629,10 @@ def dynamic_gru(input,
                 candidate_activation='tanh',
                 h_0=None):
     """
-    **Dynamic GRU Layer**
+    **Gated Recurrent Unit (GRU) Layer**
 
     Refer to `Empirical Evaluation of Gated Recurrent Neural Networks on
-    Sequence Modeling <https://arxiv.org/abs/1412.3555>`_
+    Sequence Modeling <https://arxiv.org/abs/1412.3555>`_ .
 
     The formula is as follows:
 
@@ -676,17 +679,25 @@ def dynamic_gru(input,
             Choices = ["sigmoid", "tanh", "relu", "identity"], default "sigmoid".
         candidate_activation(str): The activation for candidate hidden state.
             Choices = ["sigmoid", "tanh", "relu", "identity"], default "tanh".
-        h_0 (Variable): The hidden output of the first time step.
+        h_0 (Variable): This is initial hidden state. If not set, default is
+            zero. This is a tensor with shape (N x D), where N is the number of
+            total time steps of input mini-batch feature and D is the hidden
+            size.
 
     Returns:
         Variable: The hidden state of GRU. The shape is :math:`(T \\times D)`, \
-            and lod is the same with the input.
+            and sequence length is the same with the input.
 
     Examples:
+
         .. code-block:: python
 
+            dict_dim, emb_dim = 128, 64
+            data = fluid.layers.data(name='sequence', shape=[1],
+                                     dtype='int32', lod_level=1)
+            emb = fluid.layers.embedding(input=data, size=[dict_dim, emb_dim])
             hidden_dim = 512
-            x = fluid.layers.fc(input=data, size=hidden_dim * 3)
+            x = fluid.layers.fc(input=emb, size=hidden_dim * 3)
             hidden = fluid.layers.dynamic_gru(input=x, dim=hidden_dim)
     """
 
@@ -924,13 +935,13 @@ def dropout(x, dropout_prob, is_test=False, seed=None, name=None):
 
     Drop or keep each element of `x` independently. Dropout is a regularization
     technique for reducing overfitting by preventing neuron co-adaption during
-    training. The dropout operator randomly set (according to the given dropout
+    training. The dropout operator randomly sets (according to the given dropout
     probability) the outputs of some units to zero, while others are remain
     unchanged.
 
     Args:
-        x (Variable): The input tensor.
-         dropout_prob (float): Probability of setting units to zero.
+        x (Variable): The input tensor variable.
+        dropout_prob (float): Probability of setting units to zero.
         is_test (bool): A flag indicating whether it is in test phrase or not.
         seed (int): A Python integer used to create random seeds. If this
                     parameter is set to None, a random seed is used.
@@ -940,13 +951,14 @@ def dropout(x, dropout_prob, is_test=False, seed=None, name=None):
                          will be named automatically.
 
     Returns:
-        Variable: A tensor variable.
+        Variable: A tensor variable is the shape with `x`.
 
     Examples:
+
         .. code-block:: python
 
-          x = fluid.layers.data(name="data", shape=[32, 32], dtype="float32")
-          droped = fluid.layers.dropout(input=x, dropout_rate=0.5)
+            x = fluid.layers.data(name="data", shape=[32, 32], dtype="float32")
+            droped = fluid.layers.dropout(x, dropout_prob=0.5)
     """
 
     helper = LayerHelper('dropout', **locals())
@@ -3012,32 +3024,33 @@ def l2_normalize(x, axis, epsilon=1e-12, name=None):
     norm. For a 1-D tensor (`dim` is fixed to 0), this layer computes
 
     .. math::
-    y = \frac{x}{ \sqrt{\sum {x^2} + epsion }}
+
+        y = \\frac{x}{ \sqrt{\sum {x^2} + epsion }}
 
     For `x` with more dimensions, this layer independently normalizes each 1-D
     slice along dimension `axis`.
 
     Args:
         x(Variable|list): The input tensor to l2_normalize layer.
-        axis(int): The axis on which to apply normalization. If `axis < 0`,
+        axis(int): The axis on which to apply normalization. If `axis < 0`, \
             the dimension to normalization is rank(X) + axis. -1 is the
             last dimension.
-        epsilon(float): The epsilon value is used to avoid division by zero,
+        epsilon(float): The epsilon value is used to avoid division by zero, \
             the defalut value is 1e-10.
-        name(str|None): A name for this layer(optional). If set None, the layer
+        name(str|None): A name for this layer(optional). If set None, the layer \
             will be named automatically.
 
-
     Returns:
-        Variable: The output tensor variable.
+        Variable: The output tensor variable is the same shape with `x`.
 
     Examples:
+
         .. code-block:: python
 
-          data = fluid.layers.data(name="data",
-                                   shape=(3, 17, 13),
-                                   dtype="float32")
-          normed = fluid.layers.l2_normalize(x=data, axis=1)
+            data = fluid.layers.data(name="data",
+                                     shape=(3, 17, 13),
+                                     dtype="float32")
+            normed = fluid.layers.l2_normalize(x=data, axis=1)
     """
 
     if len(x.shape) == 1:

python/paddle/fluid/layers/tensor.py

@@ -513,11 +513,27 @@ def save_combine(x, file_path, overwrite=True):
     Saves a list of variables into a single file.
 
     Args:
-        x(list): A list of Tensor/LoDTensor to be saved together in a single file.
+        x(list): A list of Tensor/LoDTensor variables to be saved together in
+                 a single file.
         file_path(str): The file path where variables will be saved.
-        overwrite(bool): Whether or not cover the given file when it has already 
+        overwrite(bool): Whether or not cover the given file when it has already
             existed. If it's set 'False' and the file is existed, a runtime 
             error will be thrown. 
+
+    Returns:
+        There is no return value.
+
+    Examples:
+
+        .. code-block:: python
+
+            v1 = fluid.layers.data(name="data",
+                                   shape=(4, 6),
+                                   dtype="float32")
+            v2 = fluid.layers.data(name="data",
+                                   shape=(6, 8, 4),
+                                   dtype="float32")
+            normed = fluid.layers.save_combine([v1, v2], file_path="output")
     """
     helper = LayerHelper("save_combine", **locals())
     helper.append_op(

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

@@ -364,5 +364,22 @@ class TestMSRAInitializer(unittest.TestCase):
         self.assertEqual(init_op.attr('seed'), 134)
 
 
+class TestMSRAInitializer(unittest.TestCase):
+    def test_bilinear_initializer(self):
+        """Test the bilinear initializer with supplied arguments
+        """
+        program = framework.Program()
+        block = program.global_block()
+        block.create_parameter(
+            dtype="float32",
+            shape=[8, 1, 3, 3],
+            lod_level=0,
+            name="param",
+            initializer=initializer.BilinearInitializer())
+        self.assertEqual(len(block.ops), 1)
+        init_op = block.ops[0]
+        self.assertEqual(init_op.type, 'assign_value')
+
+
 if __name__ == '__main__':
     unittest.main()