示例#1
0
 def __init__(
         self,
         optimizer=None,
         optimizer_args=None,
         **kwargs):
     if optimizer is None:
         if optimizer_args is None:
             optimizer_args = dict()
         optimizer = ConjugateGradientOptimizer(**optimizer_args)
     super(TRPO, self).__init__(optimizer=optimizer, **kwargs)
    def __init__(
        self,
        name,
        input_shape,
        output_dim,
        prob_network=None,
        hidden_sizes=(32, 32),
        hidden_nonlinearity=tf.nn.tanh,
        optimizer=None,
        tr_optimizer=None,
        use_trust_region=True,
        step_size=0.01,
        normalize_inputs=True,
        no_initial_trust_region=True,
    ):
        """
        :param input_shape: Shape of the input data.
        :param output_dim: Dimension of output.
        :param hidden_sizes: Number of hidden units of each layer of the mean network.
        :param hidden_nonlinearity: Non-linearity used for each layer of the mean network.
        :param optimizer: Optimizer for minimizing the negative log-likelihood.
        :param use_trust_region: Whether to use trust region constraint.
        :param step_size: KL divergence constraint for each iteration
        """
        Serializable.quick_init(self, locals())

        with tf.variable_scope(name):
            if optimizer is None:
                optimizer = LbfgsOptimizer(name="optimizer")
            if tr_optimizer is None:
                tr_optimizer = ConjugateGradientOptimizer()

            self.output_dim = output_dim
            self.optimizer = optimizer
            self.tr_optimizer = tr_optimizer

            if prob_network is None:
                prob_network = MLP(input_shape=input_shape,
                                   output_dim=output_dim,
                                   hidden_sizes=hidden_sizes,
                                   hidden_nonlinearity=hidden_nonlinearity,
                                   output_nonlinearity=tf.nn.softmax,
                                   name="prob_network")

            l_prob = prob_network.output_layer

            LayersPowered.__init__(self, [l_prob])

            xs_var = prob_network.input_layer.input_var
            ys_var = tf.placeholder(dtype=tf.float32,
                                    shape=[None, output_dim],
                                    name="ys")
            old_prob_var = tf.placeholder(dtype=tf.float32,
                                          shape=[None, output_dim],
                                          name="old_prob")

            x_mean_var = tf.get_variable(name="x_mean",
                                         shape=(1, ) + input_shape,
                                         initializer=tf.constant_initializer(
                                             0., dtype=tf.float32))
            x_std_var = tf.get_variable(name="x_std",
                                        shape=(1, ) + input_shape,
                                        initializer=tf.constant_initializer(
                                            1., dtype=tf.float32))

            normalized_xs_var = (xs_var - x_mean_var) / x_std_var

            prob_var = L.get_output(
                l_prob, {prob_network.input_layer: normalized_xs_var})

            old_info_vars = dict(prob=old_prob_var)
            info_vars = dict(prob=prob_var)

            dist = self._dist = Categorical(output_dim)

            mean_kl = tf.reduce_mean(dist.kl_sym(old_info_vars, info_vars))

            loss = -tf.reduce_mean(dist.log_likelihood_sym(ys_var, info_vars))

            predicted = tensor_utils.to_onehot_sym(
                tf.argmax(prob_var, dimension=1), output_dim)

            self.prob_network = prob_network
            self.f_predict = tensor_utils.compile_function([xs_var], predicted)
            self.f_prob = tensor_utils.compile_function([xs_var], prob_var)
            self.l_prob = l_prob

            self.optimizer.update_opt(loss=loss,
                                      target=self,
                                      network_outputs=[prob_var],
                                      inputs=[xs_var, ys_var])
            self.tr_optimizer.update_opt(loss=loss,
                                         target=self,
                                         network_outputs=[prob_var],
                                         inputs=[xs_var, ys_var, old_prob_var],
                                         leq_constraint=(mean_kl, step_size))

            self.use_trust_region = use_trust_region
            self.name = name

            self.normalize_inputs = normalize_inputs
            self.x_mean_var = x_mean_var
            self.x_std_var = x_std_var
            self.first_optimized = not no_initial_trust_region
示例#3
0
stub(globals())

env = TfEnv(normalize(CartpoleEnv()))

policy = GaussianLSTMPolicy(
    name="policy",
    env_spec=env.spec,
    lstm_layer_cls=L.TfBasicLSTMLayer,
    # gru_layer_cls=L.GRULayer,
)

baseline = LinearFeatureBaseline(env_spec=env.spec)

algo = TRPO(
    env=env,
    policy=policy,
    baseline=baseline,
    batch_size=4000,
    max_path_length=100,
    n_itr=10,
    discount=0.99,
    step_size=0.01,
    optimizer=ConjugateGradientOptimizer(hvp_approach=FiniteDifferenceHvp(base_eps=1e-5))
)
run_experiment_lite(
    algo.train(),
    n_parallel=4,
    seed=1,
)