tf.contrib.layers.legacy_fully_connected(x, num_output_units, activation_fn=None, weight_init=initializers.xavier_initializer(), bias_init=tf.zeros_initializer(), name=None, weight_collections=(ops.GraphKeys.WEIGHTS,), bias_collections=(ops.GraphKeys.BIASES,), output_collections=(ops.GraphKeys.ACTIVATIONS,), trainable=True, weight_regularizer=None, bias_regularizer=None)
Adds the parameters for a fully connected layer and returns the output.
A fully connected layer is generally defined as a matrix multiply: y = f(w * x + b)
where f
is given by activation_fn
. If activation_fn
is None
, the result of y = w * x + b
is returned.
If x
has shape [\(\text{dim}0, \text{dim}_1, ..., \text{dim}_n\)] with more than 2 dimensions (\(n > 1\)), then we repeat the matrix multiply along the first dimensions. The result r is a tensor of shape [\(\text{dim}_0, ..., \text{dim}{n-1},\) num_output_units
], where \( r_{i_0, ..., i_{n-1}, k} = \sum_{0 \leq j < \text{dim}n} x{i_0, ... i_{n-1}, j} \cdot w_{j, k}\). This is accomplished by reshaping x
to 2-D [\(\text{dim}0 \cdot ... \cdot \text{dim}{n-1}, \text{dim}n\)] before the matrix multiply and afterwards reshaping it to [\(\text{dim}_0, ..., \text{dim}{n-1},\) num_output_units
].
This op creates w
and optionally b
. Bias (b
) can be disabled by setting bias_init
to None
.
The variable creation is compatible with tf.variable_scope
and so can be reused with tf.variable_scope
or tf.make_template
.
Most of the details of variable creation can be controlled by specifying the initializers (weight_init
and bias_init
) and in which collections to place the created variables (weight_collections
and bias_collections
; note that the variables are always added to the VARIABLES
collection). The output of the layer can be placed in custom collections using output_collections
. The collections arguments default to WEIGHTS
, BIASES
and ACTIVATIONS
, respectively.
A per layer regularization can be specified by setting weight_regularizer
and bias_regularizer
, which are applied to the weights and biases respectively, and whose output is added to the REGULARIZATION_LOSSES
collection.
x
: The input Tensor
.num_output_units
: The size of the output.activation_fn
: activation function, default set to None to skip it and maintain a linear activation.weight_init
: An optional weight initialization, defaults to xavier_initializer
.bias_init
: An initializer for the bias, defaults to 0. Set to None
in order to disable bias.name
: The name for this operation is used to name operations and to find variables. If specified it must be unique for this scope, otherwise a unique name starting with "fully_connected" will be created. See tf.variable_scope
for details.weight_collections
: List of graph collections to which weights are added.bias_collections
: List of graph collections to which biases are added.output_collections
: List of graph collections to which outputs are added.trainable
: If True
also add variables to the graph collection GraphKeys.TRAINABLE_VARIABLES
(see tf.Variable).weight_regularizer
: A regularizer like the result of l1_regularizer
or l2_regularizer
. Used for weights.bias_regularizer
: A regularizer like the result of l1_regularizer
or l2_regularizer
. Used for biases.The output of the fully connected layer.
ValueError
: if x has rank less than 2 or if its last dimension is not set.Defined in tensorflow/contrib/layers/python/layers/layers.py
.
© 2017 The TensorFlow Authors. All rights reserved.
Licensed under the Creative Commons Attribution License 3.0.
Code samples licensed under the Apache 2.0 License.
https://www.tensorflow.org/api_docs/python/tf/contrib/layers/legacy_fully_connected