Files
easy-rl/codes/QLearning/agent.py
JohnJim0816 6e4d966e1f update
2021-03-28 11:18:52 +08:00

56 lines
1.9 KiB
Python

#!/usr/bin/env python
# coding=utf-8
'''
Author: John
Email: johnjim0816@gmail.com
Date: 2020-09-11 23:03:00
LastEditor: John
LastEditTime: 2021-03-26 16:51:01
Discription:
Environment:
'''
import numpy as np
import math
import torch
from collections import defaultdict
class QLearning(object):
def __init__(self,
action_dim,cfg):
self.action_dim = action_dim # dimension of acgtion
self.lr = cfg.lr # learning rate
self.gamma = cfg.gamma
self.epsilon = 0
self.sample_count = 0
self.epsilon_start = cfg.epsilon_start
self.epsilon_end = cfg.epsilon_end
self.epsilon_decay = cfg.epsilon_decay
self.Q_table = defaultdict(lambda: np.zeros(action_dim)) # A nested dictionary that maps state -> (action -> action-value)
def choose_action(self, state):
self.sample_count += 1
self.epsilon = self.epsilon_end + (self.epsilon_start - self.epsilon_end) * \
math.exp(-1. * self.sample_count / self.epsilon_decay)
# e-greedy policy
if np.random.uniform(0, 1) > self.epsilon:
action = np.argmax(self.Q_table[str(state)])
else:
action = np.random.choice(self.action_dim)
return action
def update(self, state, action, reward, next_state, done):
Q_predict = self.Q_table[str(state)][action]
if done:
Q_target = reward # terminal state
else:
Q_target = reward + self.gamma * np.max(self.Q_table[str(next_state)])
self.Q_table[str(state)][action] += self.lr * (Q_target - Q_predict)
def save(self,path):
import dill
torch.save(
obj=self.Q_table,
f=path+"Qleaning_model.pkl",
pickle_module=dill
)
def load(self, path):
import dill
self.Q_table =torch.load(f=path+'Qleaning_model.pkl',pickle_module=dill)