stable-baselines3/torchy_baselines/common/policies.py
Antonin Raffin b4dc9d4e4d Add doc
2019-09-26 11:46:40 +02:00

143 lines
4.3 KiB
Python

import torch as th
import torch.nn as nn
class BasePolicy(nn.Module):
"""
The base policy object
:param observation_space: (Gym Space) The observation space of the environment
:param action_space: (Gym Space) The action space of the environment
"""
def __init__(self, observation_space, action_space, device='cpu'):
super(BasePolicy, self).__init__()
self.observation_space = observation_space
self.action_space = action_space
self.device = device
@staticmethod
def init_weights(module, gain=1):
if type(module) == nn.Linear:
nn.init.orthogonal_(module.weight, gain=gain)
module.bias.data.fill_(0.0)
def forward(self, *_args, **kwargs):
raise NotImplementedError()
def save(self, path):
"""
Save model to a given location.
:param path: (str)
"""
th.save(self.state_dict(), path)
def load(self, path):
"""
Load saved model from path.
:param path: (str)
"""
self.load_state_dict(th.load(path))
def load_from_vector(self, vector):
"""
Load parameters from a 1D vector.
:param vector: (np.ndarray)
"""
th.nn.utils.vector_to_parameters(th.FloatTensor(vector).to(self.device), self.parameters())
def parameters_to_vector(self):
"""
Convert the parameters to a 1D vector.
:return: (np.ndarray)
"""
return th.nn.utils.parameters_to_vector(self.parameters()).detach().cpu().numpy()
def create_mlp(input_dim, output_dim, net_arch,
activation_fn=nn.ReLU, squash_out=False):
modules = [nn.Linear(input_dim, net_arch[0]), activation_fn()]
for idx in range(len(net_arch) - 1):
modules.append(nn.Linear(net_arch[idx], net_arch[idx + 1]))
modules.append(activation_fn())
if output_dim > 0:
modules.append(nn.Linear(net_arch[-1], output_dim))
if squash_out:
modules.append(nn.Tanh())
return modules
class BaseNetwork(nn.Module):
"""docstring for BaseNetwork."""
def __init__(self):
super(BaseNetwork, self).__init__()
def load_from_vector(self, vector):
"""
Load parameters from a 1D vector.
:param vector: (np.ndarray)
"""
device = next(self.parameters()).device
th.nn.utils.vector_to_parameters(th.FloatTensor(vector).to(device), self.parameters())
def parameters_to_vector(self):
"""
Convert the parameters to a 1D vector.
:return: (np.ndarray)
"""
return th.nn.utils.parameters_to_vector(self.parameters()).detach().cpu().numpy()
_policy_registry = dict()
def get_policy_from_name(base_policy_type, name):
"""
returns the registed policy from the base type and name
:param base_policy_type: (BasePolicy) the base policy object
:param name: (str) the policy name
:return: (base_policy_type) the policy
"""
if base_policy_type not in _policy_registry:
raise ValueError("Error: the policy type {} is not registered!".format(base_policy_type))
if name not in _policy_registry[base_policy_type]:
raise ValueError("Error: unknown policy type {}, the only registed policy type are: {}!"
.format(name, list(_policy_registry[base_policy_type].keys())))
return _policy_registry[base_policy_type][name]
def register_policy(name, policy):
"""
returns the registed policy from the base type and name
:param name: (str) the policy name
:param policy: (subclass of BasePolicy) the policy
"""
sub_class = None
# For building the doc
try:
for cls in BasePolicy.__subclasses__():
if issubclass(policy, cls):
sub_class = cls
break
except AttributeError:
sub_class = str(th.random.randint(100))
if sub_class is None:
raise ValueError("Error: the policy {} is not of any known subclasses of BasePolicy!".format(policy))
if sub_class not in _policy_registry:
_policy_registry[sub_class] = {}
if name in _policy_registry[sub_class]:
raise ValueError("Error: the name {} is alreay registered for a different policy, will not override."
.format(name))
_policy_registry[sub_class][name] = policy