Renforcer l'apprentissage 17 Colaboratory + CartPole + ChainerRL

On suppose que vous avez terminé l'apprentissage par renforcement 16. Après essais et erreurs, cela ressemble à ceci. Le fait est que vous pouvez enregistrer et charger des fichiers directement sur Google Drive. Je ne peux pas effacer la figure qui apparaît sous la dernière animation.

Monture Google Drive

import google.colab.drive
google.colab.drive.mount('gdrive')
!ln -s gdrive/My\ Drive mydrive

Installation

!apt-get install -y xvfb python-opengl ffmpeg > /dev/null 2>&1
!pip install pyvirtualdisplay > /dev/null 2>&1
!pip -q install JSAnimation
!pip -q install chainerrl

Initialisation des paramètres

gamename='CartPole-v0'
# Set the discount factor that discounts future rewards.
gamma = 0.95
# Use epsilon-greedy for exploration
myepsilon=0.3

mySteps=20000 # Train the agent for 2000 steps
my_eval_n_episodes=1 # 10 episodes are sampled for each evaluation
my_eval_max_episode_len=200  # Maximum length of each episodes
my_eval_interval=1000   # Evaluate the agent after every 1000 steps
myOutDir='mydrive/OpenAI/CartPole/result'      # Save everything to 'result' directory
myAgentDir='mydrive/OpenAI/CartPole/agent'      # Save Agent to 'agent' directory
myAnimName='mydrive/OpenAI/CartPole/movie_cartpole.mp4'
myScoreName="mydrive/OpenAI/CartPole/result/scores.txt"

Program

import

import chainer
import chainer.functions as F
import chainer.links as L
import chainerrl
import gym
import numpy as np

env initialize

env = gym.make(gamename)
print('observation space:', env.observation_space)
print('action space:', env.action_space)

obs = env.reset()
print('initial observation:', obs)
action = env.action_space.sample()
obs, r, done, info = env.step(action)
print('next observation:', obs)
print('reward:', r)
print('done:', done)
print('info:', info)

Deep Q Network setting

obs_size = env.observation_space.shape[0]
n_actions = env.action_space.n
q_func = chainerrl.q_functions.FCStateQFunctionWithDiscreteAction(
    obs_size, n_actions,
    n_hidden_layers=2, n_hidden_channels=50)

Use Adam to optimize q_func. eps=1e-2 is for stability.

optimizer = chainer.optimizers.Adam(eps=1e-2)
optimizer.setup(q_func)

Agent Setting DQN uses Experience Replay.

Specify a replay buffer and its capacity.

Since observations from CartPole-v0 is numpy.float64 while

Chainer only accepts numpy.float32 by default, specify a converter as a feature extractor function phi.

explorer = chainerrl.explorers.ConstantEpsilonGreedy(
    epsilon=myepsilon, random_action_func=env.action_space.sample)
replay_buffer = chainerrl.replay_buffer.ReplayBuffer(capacity=10 ** 6)
phi = lambda x: x.astype(np.float32, copy=False)
agent = chainerrl.agents.DoubleDQN(
    q_func, optimizer, replay_buffer, gamma, explorer,
    replay_start_size=500, update_interval=1,
    target_update_interval=100, phi=phi)

Train

Set up the logger to print info messages for understandability.

import logging
import sys
logging.basicConfig(level=logging.INFO, stream=sys.stdout, format='')
chainerrl.experiments.train_agent_with_evaluation(
    agent, env,steps=mySteps,eval_n_steps=None,eval_n_episodes=my_eval_n_episodes,eval_max_episode_len=my_eval_max_episode_len,
    eval_interval=my_eval_interval,outdir=myOutDir)
agent.save(myAgentDir)

Data Table

import pandas as pd
import glob
import os
score_files = glob.glob(myScoreName)
score_files.sort(key=os.path.getmtime)
score_file = score_files[-1]
df = pd.read_csv(score_file, delimiter='\t' )
df

figure Average_Q

df.plot(x='steps',y='average_q')

Test

import2

from pyvirtualdisplay import Display
display = Display(visible=0, size=(1024, 768))
display.start()

from JSAnimation.IPython_display import display_animation
from matplotlib import animation
import matplotlib.pyplot as plt
%matplotlib inline

Test Program

frames = []
env = gym.make(gamename)
envw = gym.wrappers.Monitor(env, myOutDir, force=True)

for i in range(3):
    obs = envw.reset()
    done = False
    R = 0
    t = 0
    while not done and t < 200:
        frames.append(envw.render(mode = 'rgb_array'))
        action = agent.act(obs)
        obs, r, done, _ = envw.step(action)
        R += r
        t += 1
    print('test episode:', i, 'R:', R)
    agent.stop_episode()
envw.render()
envw.close()

from IPython.display import HTML
plt.figure(figsize=(frames[0].shape[1]/72.0, frames[0].shape[0]/72.0),dpi=72)
patch = plt.imshow(frames[0])
plt.axis('off') 
def animate(i):
    patch.set_data(frames[i])
anim = animation.FuncAnimation(plt.gcf(), animate, frames=len(frames),interval=50)
anim.save(myAnimName)
HTML(anim.to_jshtml())