Files
2021-02-18 13:04:44 +08:00

264 lines
8.4 KiB
Python

import torch
import numpy as np
import torch.nn as nn
import gym
import os
import random
from torch.utils.data import Dataset, DataLoader
import time
from skimage.util.shape import view_as_windows
from diy_gym.utils import flatten, unflatten
class eval_mode(object):
def __init__(self, *models):
self.models = models
def __enter__(self):
self.prev_states = []
for model in self.models:
self.prev_states.append(model.training)
model.train(False)
def __exit__(self, *args):
for model, state in zip(self.models, self.prev_states):
model.train(state)
return False
def soft_update_params(net, target_net, tau):
for param, target_param in zip(net.parameters(), target_net.parameters()):
target_param.data.copy_(
tau * param.data + (1 - tau) * target_param.data
)
def set_seed_everywhere(seed):
torch.manual_seed(seed)
if torch.cuda.is_available():
torch.cuda.manual_seed_all(seed)
np.random.seed(seed)
random.seed(seed)
def module_hash(module):
result = 0
for tensor in module.state_dict().values():
result += tensor.sum().item()
return result
def make_dir(dir_path):
os.makedirs(dir_path, exist_ok=True)
return dir_path
def preprocess_obs(obs, bits=5):
"""Preprocessing image, see https://arxiv.org/abs/1807.03039."""
bins = 2**bits
assert obs.dtype == torch.float32
if bits < 8:
obs = torch.floor(obs / 2**(8 - bits))
obs = obs / bins
obs = obs + torch.rand_like(obs) / bins
obs = obs - 0.5
return obs
class ReplayBuffer(Dataset):
"""Buffer to store environment transitions."""
def __init__(self, obs_space, action_space, capacity, batch_size, device, image_size=84, transform=None):
obs_shape = flatten(obs_space.sample()).shape
action_shape = action_space.shape
self.obs_space = obs_space
self.capacity = capacity
self.batch_size = batch_size
self.device = device
self.image_size = image_size
self.transform = transform
# the proprioceptive obs is stored as float32, mixeds obs as uint8
obs_dtype = np.float16 if len(obs_shape) == 1 else np.uint8
self.obses = np.empty((capacity, *obs_shape), dtype=obs_dtype)
self.next_obses = np.empty((capacity, *obs_shape), dtype=obs_dtype)
self.actions = np.empty((capacity, *action_shape), dtype=np.float32)
self.rewards = np.empty((capacity, 1), dtype=np.float32)
self.not_dones = np.empty((capacity, 1), dtype=np.float32)
self.idx = 0
self.last_save = 0
self.full = False
def add(self, obs, action, reward, next_obs, done):
obs = flatten(obs)
next_obs = flatten(next_obs)
np.copyto(self.obses[self.idx], obs)
np.copyto(self.actions[self.idx], action)
np.copyto(self.rewards[self.idx], reward)
np.copyto(self.next_obses[self.idx], next_obs)
np.copyto(self.not_dones[self.idx], not done)
self.idx = (self.idx + 1) % self.capacity
self.full = self.full or self.idx == 0
def unflatten_obs(self, obs):
obs = [unflatten(o, self.obs_space) for o in obs]
obs = {
k: np.stack([o[k] for o in obs])
for k in obs[0].keys()
}
return obs
def sample_proprio(self):
idxs = np.random.randint(
0, self.capacity if self.full else self.idx, size=self.batch_size
)
obses = self.as_tensor_obs(self.unflatten_obs(self.obses[idxs]))
next_obses = self.as_tensor_obs(self.unflatten_obs(self.next_obses[idxs]))
actions = torch.as_tensor(self.actions[idxs], device=self.device)
rewards = torch.as_tensor(self.rewards[idxs], device=self.device)
not_dones = torch.as_tensor(self.not_dones[idxs], device=self.device)
return obses, actions, rewards, next_obses, not_dones
def sample_cpc(self):
start = time.time()
idxs = np.random.randint(
0, self.capacity if self.full else self.idx, size=self.batch_size
)
obses_raw = self.unflatten_obs(self.obses[idxs])
next_obses_raw = self.unflatten_obs(self.next_obses[idxs])
# Split mixed obs into image and state
state, obses = split_obs(obses_raw)
next_state, next_obses = split_obs(next_obses_raw)
pos = obses.copy()
# Crop
obses = random_crop(obses, self.image_size)
next_obses = random_crop(next_obses, self.image_size)
pos = random_crop(pos, self.image_size)
# Recombine
obses = self.as_tensor_obs(combine_obs(state, obses))
next_obses = self.as_tensor_obs(combine_obs(next_state, next_obses))
pos = self.as_tensor_obs(combine_obs(state, pos))
actions = torch.as_tensor(self.actions[idxs], device=self.device)
rewards = torch.as_tensor(self.rewards[idxs], device=self.device)
not_dones = torch.as_tensor(self.not_dones[idxs], device=self.device)
cpc_kwargs = dict(obs_anchor=obses, obs_pos=pos,
time_anchor=None, time_pos=None)
return obses, actions, rewards, next_obses, not_dones, cpc_kwargs
def as_tensor_obs(self, obses):
obses['img'] = torch.as_tensor(obses['img'], device=self.device).float()
obses['state'] = torch.as_tensor(obses['state'], device=self.device).float()
return obses
def save(self, save_dir):
if self.idx == self.last_save:
return
path = os.path.join(save_dir, '%d_%d.pt' % (self.last_save, self.idx))
payload = [
self.obses[self.last_save:self.idx],
self.next_obses[self.last_save:self.idx],
self.actions[self.last_save:self.idx],
self.rewards[self.last_save:self.idx],
self.not_dones[self.last_save:self.idx]
]
self.last_save = self.idx
torch.save(payload, path)
def load(self, save_dir):
chunks = os.listdir(save_dir)
chucks = sorted(chunks, key=lambda x: int(x.split('_')[0]))
for chunk in chucks:
start, end = [int(x) for x in chunk.split('.')[0].split('_')]
path = os.path.join(save_dir, chunk)
payload = torch.load(path)
assert self.idx == start
self.obses[start:end] = payload[0]
self.next_obses[start:end] = payload[1]
self.actions[start:end] = payload[2]
self.rewards[start:end] = payload[3]
self.not_dones[start:end] = payload[4]
self.idx = end
def __getitem__(self, idx):
idx = np.random.randint(
0, self.capacity if self.full else self.idx, size=1
)
idx = idx[0]
obs = self.unflatten_obs(self.obses[idx])
action = self.actions[idx]
reward = self.rewards[idx]
next_obs = self.unflatten_obs(self.next_obses[idx])
not_done = self.not_dones[idx]
if self.transform:
obs = self.transform(obs)
next_obs = self.transform(next_obs)
return obs, action, reward, next_obs, not_done
def __len__(self):
return self.capacity
def random_crop(imgs, output_size):
"""
Vectorized way to do random crop using sliding windows
and picking out random ones
args:
imgs, batch images with shape (B,C,H,W)
"""
# batch size
n = imgs.shape[0]
img_size = imgs.shape[-1]
crop_max = img_size - output_size
imgs = np.transpose(imgs, (0, 2, 3, 1))
w1 = np.random.randint(0, crop_max, n)
h1 = np.random.randint(0, crop_max, n)
# creates all sliding windows combinations of size (output_size)
windows = view_as_windows(
imgs, (1, output_size, output_size, 1))[..., 0,:,:, 0]
# selects a random window for each batch element
cropped_imgs = windows[np.arange(n), w1, h1]
return cropped_imgs
def center_crop_image(image, output_size):
h, w = image.shape[1:]
new_h, new_w = output_size, output_size
top = (h - new_h)//2
left = (w - new_w)//2
image = image[:, top:top + new_h, left:left + new_w]
return image
def split_obs(obs):
"""Split a dict obs into state and images."""
return obs['state'], obs['img']
def combine_obs(state, img):
return dict(state=state, img=img)
def split_obs_shape(obs_shape):
obs = np.zeros(obs_shape)
state, img = split_obs(obs)
return state.shape, img.shape