Add nn to imperative

test=develop

python/paddle/fluid/imperative/nn.py

+# Copyright (c) 2018 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.
+
+from __future__ import print_function
+
+from six.moves import reduce
+
+from .. import core
+from ..layers import utils
+from . import layers
+from ..framework import Variable, OpProtoHolder
+from ..param_attr import ParamAttr
+from ..initializer import Normal, Constant
+
+__all__ = [
+    'Conv2D',
+    'Pool2D',
+    'FC',
+]
+
+
+class Conv2D(layers.PyLayer):
+    def __init__(self,
+                 num_channels,
+                 num_filters,
+                 filter_size,
+                 stride=1,
+                 padding=0,
+                 dilation=1,
+                 groups=None,
+                 use_cudnn=True,
+                 act=None,
+                 param_attr=None,
+                 bias_attr=None,
+                 name=None,
+                 dtype=core.VarDesc.VarType.FP32):
+        assert param_attr is not False, "param_attr should not be False here."
+        super(Conv2D, self).__init__(
+            param_attr=param_attr, bias_attr=bias_attr, name=name, dtype=dtype)
+
+        self._groups = groups
+        self._stride = utils.convert_to_list(stride, 2, 'stride')
+        self._padding = utils.convert_to_list(padding, 2, 'padding')
+        self._dilation = utils.convert_to_list(dilation, 2, 'dilation')
+        if not isinstance(use_cudnn, bool):
+            raise ValueError("use_cudnn should be True or False")
+        self._use_cudnn = use_cudnn
+        self._num_channels = num_channels
+        if (self._num_channels == self._groups and
+                num_filters % self._num_channels == 0 and not self._use_cudnn):
+            self._l_type = 'depthwise_conv2d'
+        else:
+            self._l_type = 'conv2d'
+
+        if groups is None:
+            num_filter_channels = num_channels
+        else:
+            if num_channels % groups != 0:
+                raise ValueError("num_channels must be divisible by groups.")
+            num_filter_channels = num_channels // groups
+        filter_size = utils.convert_to_list(filter_size, 2, 'filter_size')
+        filter_shape = [num_filters, int(num_filter_channels)] + filter_size
+
+        def _get_default_param_initializer():
+            filter_elem_num = filter_size[0] * filter_size[1] * num_channels
+            std = (2.0 / filter_elem_num)**0.5
+            return Normal(0.0, std, 0)
+
+        self._filter_param = self._helper.create_parameter(
+            attr=self._helper.param_attr,
+            shape=filter_shape,
+            dtype=self._dtype,
+            default_initializer=_get_default_param_initializer())
+
+        if self._use_cudnn:
+            self._helper.create_variable(
+                name="kCUDNNFwdAlgoCache",
+                persistable=True,
+                type=core.VarDesc.VarType.RAW)
+            self._helper.create_variable(
+                name="kCUDNNBwdDataAlgoCache",
+                persistable=True,
+                type=core.VarDesc.VarType.RAW)
+            self._helper.create_variable(
+                name="kCUDNNBwdFilterAlgoCache",
+                persistable=True,
+                type=core.VarDesc.VarType.RAW)
+
+        self._pre_bias = self._helper.create_variable_for_type_inference(
+            dtype=self._dtype)
+
+    def forward(self, input):
+        self._helper.append_op(
+            type=self._l_type,
+            inputs={
+                'Input': input,
+                'Filter': self._filter_param,
+            },
+            outputs={"Output": self._pre_bias},
+            attrs={
+                'strides': self._stride,
+                'paddings': self._padding,
+                'dilations': self._dilation,
+                'groups': self._groups,
+                'use_cudnn': self._use_cudnn,
+                'use_mkldnn': False,
+            })
+
+        self._pre_act = self._helper.append_bias_op(
+            self._pre_bias, dim_start=1, dim_end=2)
+
+        out = self._helper.append_activation(self._pre_act)
+        return out
+
+
+class Pool2D(layers.PyLayer):
+    def __init__(self,
+                 pool_size=-1,
+                 pool_type="max",
+                 pool_stride=1,
+                 pool_padding=0,
+                 global_pooling=False,
+                 use_cudnn=True,
+                 ceil_mode=False,
+                 exclusive=True,
+                 name=None,
+                 dtype=core.VarDesc.VarType.FP32):
+        if pool_type not in ["max", "avg"]:
+            raise ValueError(
+                "Unknown pool_type: '%s'. It can only be 'max' or 'avg'.",
+                str(pool_type))
+
+        if global_pooling is False and pool_size == -1:
+            raise ValueError(
+                "When the global_pooling is False, pool_size must be passed "
+                "and be a valid value. Received pool_size: " + str(pool_size))
+
+        if not isinstance(use_cudnn, bool):
+            raise ValueError("use_cudnn should be True or False")
+
+        super(Pool2D, self).__init__(name=name, dtype=dtype)
+
+        self._pool_type = pool_type
+        self._pool_size = utils.convert_to_list(pool_size, 2, 'pool_size')
+        self._pool_padding = utils.convert_to_list(pool_padding, 2,
+                                                   'pool_padding')
+        self._pool_stride = utils.convert_to_list(pool_stride, 2, 'pool_stride')
+        self._global_pooling = global_pooling
+        self._use_cudnn = use_cudnn
+        self._ceil_mode = ceil_mode
+        self._exclusive = exclusive
+        self._l_type = 'pool2d'
+
+        self._pool_out = self._helper.create_variable_for_type_inference(
+            self._dtype)
+
+    def forward(self, input):
+        self._helper.append_op(
+            type=self._l_type,
+            inputs={"X": input},
+            outputs={"Out": self._pool_out},
+            attrs={
+                "pooling_type": self._pool_type,
+                "ksize": self._pool_size,
+                "global_pooling": self._global_pooling,
+                "strides": self._pool_stride,
+                "paddings": self._pool_padding,
+                "use_cudnn": self._use_cudnn,
+                "ceil_mode": self._ceil_mode,
+                "use_mkldnn": False,
+                "exclusive": self._exclusive,
+            })
+        return self._pool_out
+
+
+class FC(layers.PyLayer):
+    def __init__(self,
+                 size_in,
+                 size_out,
+                 num_flatten_dims=1,
+                 param_attr=None,
+                 dtype=core.VarDesc.VarType.FP32):
+        super(FC, self).__init__(param_attr=param_attr, dtype=dtype)
+
+        self._size_in = size_in
+        self._size_out = size_out
+        self._num_flatten_dims = num_flatten_dims
+        self._dtype = dtype
+        if self._size_in != -1:
+            self._w = self._helper.create_parameter(
+                attr=self._helper.param_attr,
+                shape=[size_in, size_out],
+                dtype=self._dtype,
+                is_bias=False)
+        self._tmp = self._helper.create_variable_for_type_inference(self._dtype)
+        self._out = self._helper.create_variable_for_type_inference(self._dtype)
+
+    def _build_once(self, input):
+        if self._size_in != -1:
+            return
+
+        input_shape = input.shape
+        param_shape = [
+            reduce(lambda a, b: a * b, input_shape[self._num_flatten_dims:], 1)
+        ] + [self._size_out]
+        self._w = self._helper.create_parameter(
+            attr=self._helper.param_attr,
+            shape=param_shape,
+            dtype=self._dtype,
+            is_bias=False)
+
+    def forward(self, input):
+        self._helper.append_op(
+            type="mul",
+            inputs={"X": input,
+                    "Y": self._w},
+            outputs={"Out": self._tmp},
+            attrs={
+                "x_num_col_dims": self._num_flatten_dims,
+                "y_num_col_dims": 1
+            })
+
+        self._helper.append_op(
+            type="sum",
+            inputs={"X": [self._tmp]},
+            outputs={"Out": self._out},
+            attrs={"use_mkldnn": False})
+        return self._out