ray/rllib/models/torch/fcnet.py

65 lines
2.2 KiB
Python

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function
import logging
import numpy as np
import torch.nn as nn
from ray.rllib.models.torch.torch_modelv2 import TorchModelV2
from ray.rllib.models.torch.misc import normc_initializer, SlimFC, \
_get_activation_fn
from ray.rllib.utils.annotations import override
logger = logging.getLogger(__name__)
class FullyConnectedNetwork(TorchModelV2, nn.Module):
"""Generic fully connected network."""
def __init__(self, obs_space, action_space, num_outputs, model_config,
name):
TorchModelV2.__init__(self, obs_space, action_space, num_outputs,
model_config, name)
nn.Module.__init__(self)
hiddens = model_config.get("fcnet_hiddens")
activation = _get_activation_fn(model_config.get("fcnet_activation"))
logger.debug("Constructing fcnet {} {}".format(hiddens, activation))
layers = []
last_layer_size = np.product(obs_space.shape)
for size in hiddens:
layers.append(
SlimFC(
in_size=last_layer_size,
out_size=size,
initializer=normc_initializer(1.0),
activation_fn=activation))
last_layer_size = size
self._hidden_layers = nn.Sequential(*layers)
self._logits = SlimFC(
in_size=last_layer_size,
out_size=num_outputs,
initializer=normc_initializer(0.01),
activation_fn=None)
self._value_branch = SlimFC(
in_size=last_layer_size,
out_size=1,
initializer=normc_initializer(1.0),
activation_fn=None)
self._cur_value = None
@override(TorchModelV2)
def forward(self, input_dict, state, seq_lens):
obs = input_dict["obs_flat"]
features = self._hidden_layers(obs.reshape(obs.shape[0], -1))
logits = self._logits(features)
self._cur_value = self._value_branch(features).squeeze(1)
return logits, state
@override(TorchModelV2)
def value_function(self):
assert self._cur_value is not None, "must call forward() first"
return self._cur_value