ray/rllib/algorithms/qmix/model.py

42 lines
1.5 KiB
Python

from ray.rllib.models.modelv2 import ModelV2
from ray.rllib.models.preprocessors import get_preprocessor
from ray.rllib.models.torch.torch_modelv2 import TorchModelV2
from ray.rllib.utils.annotations import override
from ray.rllib.utils.framework import try_import_torch
torch, nn = try_import_torch()
class RNNModel(TorchModelV2, nn.Module):
"""The default RNN model for QMIX."""
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)
self.obs_size = _get_size(obs_space)
self.rnn_hidden_dim = model_config["lstm_cell_size"]
self.fc1 = nn.Linear(self.obs_size, self.rnn_hidden_dim)
self.rnn = nn.GRUCell(self.rnn_hidden_dim, self.rnn_hidden_dim)
self.fc2 = nn.Linear(self.rnn_hidden_dim, num_outputs)
self.n_agents = model_config["n_agents"]
@override(ModelV2)
def get_initial_state(self):
# Place hidden states on same device as model.
return [
self.fc1.weight.new(self.n_agents, self.rnn_hidden_dim).zero_().squeeze(0)
]
@override(ModelV2)
def forward(self, input_dict, hidden_state, seq_lens):
x = nn.functional.relu(self.fc1(input_dict["obs_flat"].float()))
h_in = hidden_state[0].reshape(-1, self.rnn_hidden_dim)
h = self.rnn(x, h_in)
q = self.fc2(h)
return q, [h]
def _get_size(obs_space):
return get_preprocessor(obs_space)(obs_space).size