"""Categorical CNN Model.
A model represented by a Categorical distribution
which is parameterized by a convolutional neural network (CNN)
followed a multilayer perceptron (MLP).
"""
import tensorflow as tf
from garage.tf.models.categorical_mlp_model import CategoricalMLPModel
from garage.tf.models.cnn_model import CNNModel
from garage.tf.models.model import Model
[docs]class CategoricalCNNModel(Model):
"""Categorical CNN Model.
A model represented by a Categorical distribution
which is parameterized by a convolutional neural network (CNN) followed
by a multilayer perceptron (MLP).
Args:
output_dim (int): Dimension of the network output.
filters (Tuple[Tuple[int, Tuple[int, int]], ...]): Number and dimension
of filters. For example, ((3, (3, 5)), (32, (3, 3))) means there
are two convolutional layers. The filter for the first layer have 3
channels and its shape is (3 x 5), while the filter for the second
layer have 32 channels and its shape is (3 x 3).
strides (tuple[int]): The stride of the sliding window. For example,
(1, 2) means there are two convolutional layers. The stride of the
filter for first layer is 1 and that of the second layer is 2.
padding (str): The type of padding algorithm to use,
either 'SAME' or 'VALID'.
hidden_sizes (list[int]): Output dimension of dense layer(s).
For example, (32, 32) means this MLP consists of two
hidden layers, each with 32 hidden units.
name (str): Model name, also the variable scope.
hidden_nonlinearity (callable): Activation function for intermediate
dense layer(s). It should return a tf.Tensor. Set it to
None to maintain a linear activation.
hidden_w_init (callable): Initializer function for the weight
of intermediate dense layer(s). The function should return a
tf.Tensor.
hidden_b_init (callable): Initializer function for the bias
of intermediate dense layer(s). The function should return a
tf.Tensor.
output_nonlinearity (callable): Activation function for output dense
layer. It should return a tf.Tensor. Set it to None to
maintain a linear activation.
output_w_init (callable): Initializer function for the weight
of output dense layer(s). The function should return a
tf.Tensor.
output_b_init (callable): Initializer function for the bias
of output dense layer(s). The function should return a
tf.Tensor.
layer_normalization (bool): Bool for using layer normalization or not.
"""
def __init__(self,
output_dim,
filters,
strides,
padding,
name=None,
hidden_sizes=(32, 32),
hidden_nonlinearity=tf.nn.relu,
hidden_w_init=tf.initializers.glorot_uniform(),
hidden_b_init=tf.zeros_initializer(),
output_nonlinearity=None,
output_w_init=tf.initializers.glorot_uniform(),
output_b_init=tf.zeros_initializer(),
layer_normalization=False):
super().__init__(name)
self._cnn_model = CNNModel(filters=filters,
strides=strides,
padding=padding,
hidden_nonlinearity=hidden_nonlinearity,
name='CNNModel')
self._mlp_model = CategoricalMLPModel(
output_dim=output_dim,
hidden_sizes=hidden_sizes,
hidden_nonlinearity=hidden_nonlinearity,
hidden_w_init=hidden_w_init,
hidden_b_init=hidden_b_init,
output_nonlinearity=output_nonlinearity,
output_w_init=output_w_init,
output_b_init=output_b_init,
layer_normalization=layer_normalization,
name='MLPModel')
[docs] def network_output_spec(self):
"""Network output spec.
Returns:
list[str]: Name of the model outputs, in order.
"""
return self._mlp_model.network_output_spec()
# pylint: disable=arguments-differ
def _build(self, state_input, name=None):
"""Build model.
Args:
state_input (tf.Tensor): Observation inputs.
name (str): Inner model name, also the variable scope of the
inner model, if exist. One example is
garage.tf.models.Sequential.
Returns:
tfp.distributions.OneHotCategorical: Policy distribution.
"""
time_dim = tf.shape(state_input)[1]
dim = state_input.get_shape()[2:].as_list()
state_input = tf.reshape(state_input, [-1, *dim])
cnn_output = self._cnn_model.build(state_input, name=name).outputs
dim = cnn_output.get_shape()[-1]
cnn_output = tf.reshape(cnn_output, [-1, time_dim, dim])
mlp_output = self._mlp_model.build(cnn_output, name=name).dist
return mlp_output