def __init__(self,
gravity=9.8,
masscart=1.0,
masspole=0.1,
length=.5,
gamma=0.99,
tau=.02,
init_state_params=None,
name="Cart-Pendulum"):
if init_state_params is None:
init_state = CartPoleState(x=0, x_dot=0, theta=0, theta_dot=0)
else:
init_state = CartPoleState(x=init_state_params["x"], x_dot=init_state_params["x_dot"],\
theta=init_state_params["theta"], theta_dot=init_state_params["theta_dot"])
MDP.__init__(self, CartPoleMDP.ACTIONS, self._transition_func, self._reward_func, init_state=init_state, gamma=gamma)
#from parameters
self.gravity = gravity
self.masscart = masscart
self.masspole = masspole
self.length = length
self.gamma = gamma
self.tau = tau
self.name = name
#thresholds
self.x_threshold = 2.4 #abs val of limit of x position of cart
self.theta_threshold = self._degrees_to_radians(20) #angle away from vertical before being considered terminal
#computed
self.total_mass = (self.masscart + self.masspole)
self.polemass_length = (self.masspole * self.length)
def _transition_func(self, state, action):
'''
Args:
state (State)
action (str)
Returns
(State)
'''
x, x_dot, theta, theta_dot = self._transition_helper(state, action)
next_state = CartPoleState(x=x, x_dot=x_dot, theta=theta, theta_dot=theta_dot)
#check if less than threshold values and if ternminal
if not self._is_within_threshold(theta=next_state.theta, x=next_state.x):
next_state.set_terminal(True)
return next_state
def _transition_func(self, state, action):
'''
Args:
state (State)
action (str)
Returns
(State)
'''
x, x_dot, theta, theta_dot = self._transition_helper(state, action)
next_state = CartPoleState(x=x, x_dot=x_dot, theta=theta, theta_dot=theta_dot)
#check if less than threshold values and if ternminal
if not self._is_within_threshold(theta=next_state.theta, x=next_state.x):
next_state.set_terminal(True)
return next_state
def reset(self, init_state_params=None):
'''
Args:
init_state_params (dict)
'''
if init_state_params is None:
self.init_state = copy.deepcopy(self.init_state)
else:
self.init_state = CartPoleState(x=init_state_params["x"], x_dot=init_state_params["x_dot"],\
theta=init_state_params["theta"], theta_dot=init_state_params["theta_dot"])
self.cur_state = self.init_state