Make FiniteDifferenceHvp pickleable

examples/tf/cluster_demo.py

@@ -39,7 +39,7 @@ def run_task(v):
             baseline=baseline,
             max_path_length=100,
             discount=0.99,
-            step_size=v['step_size'],
+            max_kl_step=v['step_size'],
         )
 
         runner.setup(algo=algo, env=env)

examples/tf/cluster_gym_mujoco_demo.py

@@ -40,7 +40,7 @@ def run_task(vv):
             baseline=baseline,
             max_path_length=100,
             discount=0.99,
-            step_size=vv['step_size'],
+            max_kl_step=vv['step_size'],
         )
 
         runner.setup(algo=algo, env=env)

examples/tf/trpo_swimmer.py

@@ -22,7 +22,7 @@ def run_task(*_):
             baseline=baseline,
             max_path_length=500,
             discount=0.99,
-            step_size=0.01)
+            max_kl_step=0.01)
 
         runner.setup(algo, env)
         runner.train(n_epochs=40, batch_size=4000)

src/garage/tf/optimizers/conjugate_gradient_optimizer.py

@@ -133,6 +133,16 @@ def eval(x):
 
         return eval
 
+    def __getstate__(self):
+        """Object.__getstate__."""
+        new_dict = self.__dict__.copy()
+        del new_dict['opt_fun']
+        return new_dict
+
+    def __setstate__(self, state):
+        """Object.__setstate__."""
+        self.__dict__.update(state)
+
 
 class ConjugateGradientOptimizer(Serializable):
     """Performs constrained optimization via line search.