lerobot/lerobot/common/datasets/abstract.py

160 lines
5.6 KiB
Python

import logging
from pathlib import Path
from typing import Callable
import einops
import torch
import torchrl
import tqdm
from huggingface_hub import snapshot_download
from tensordict import TensorDict
from torchrl.data.replay_buffers.replay_buffers import TensorDictReplayBuffer
from torchrl.data.replay_buffers.samplers import SliceSampler
from torchrl.data.replay_buffers.storages import TensorStorage, _collate_id
from torchrl.data.replay_buffers.writers import ImmutableDatasetWriter, Writer
from torchrl.envs.transforms.transforms import Compose
class AbstractExperienceReplay(TensorDictReplayBuffer):
def __init__(
self,
dataset_id: str,
batch_size: int = None,
*,
shuffle: bool = True,
root: Path | None = None,
pin_memory: bool = False,
prefetch: int = None,
sampler: SliceSampler = None,
collate_fn: Callable = None,
writer: Writer = None,
transform: "torchrl.envs.Transform" = None,
):
self.dataset_id = dataset_id
self.shuffle = shuffle
self.root = root
storage = self._download_or_load_dataset()
super().__init__(
storage=storage,
sampler=sampler,
writer=ImmutableDatasetWriter() if writer is None else writer,
collate_fn=_collate_id if collate_fn is None else collate_fn,
pin_memory=pin_memory,
prefetch=prefetch,
batch_size=batch_size,
transform=transform,
)
@property
def stats_patterns(self) -> dict:
return {
("observation", "state"): "b c -> c",
("observation", "image"): "b c h w -> c",
("action",): "b c -> c",
}
@property
def image_keys(self) -> list:
return [("observation", "image")]
@property
def num_cameras(self) -> int:
return len(self.image_keys)
@property
def num_samples(self) -> int:
return len(self)
@property
def num_episodes(self) -> int:
return len(self._storage._storage["episode"].unique())
@property
def transform(self):
return self._transform
def set_transform(self, transform):
if not isinstance(transform, Compose):
# required since torchrl calls `len(self._transform)` downstream
if isinstance(transform, list):
self._transform = Compose(*transform)
else:
self._transform = Compose(transform)
else:
self._transform = transform
def compute_or_load_stats(self, num_batch=100, batch_size=32) -> TensorDict:
stats_path = self.data_dir / "stats.pth"
if stats_path.exists():
stats = torch.load(stats_path)
else:
logging.info(f"compute_stats and save to {stats_path}")
stats = self._compute_stats(num_batch, batch_size)
torch.save(stats, stats_path)
return stats
def _download_or_load_dataset(self) -> torch.StorageBase:
if self.root is None:
self.data_dir = Path(snapshot_download(repo_id=f"cadene/{self.dataset_id}", repo_type="dataset"))
else:
self.data_dir = self.root / self.dataset_id
return TensorStorage(TensorDict.load_memmap(self.data_dir))
def _compute_stats(self, num_batch=100, batch_size=32):
rb = TensorDictReplayBuffer(
storage=self._storage,
batch_size=batch_size,
prefetch=True,
)
mean, std, max, min = {}, {}, {}, {}
# compute mean, min, max
for _ in tqdm.tqdm(range(num_batch)):
batch = rb.sample()
for key, pattern in self.stats_patterns.items():
batch[key] = batch[key].float()
if key not in mean:
# first batch initialize mean, min, max
mean[key] = einops.reduce(batch[key], pattern, "mean")
max[key] = einops.reduce(batch[key], pattern, "max")
min[key] = einops.reduce(batch[key], pattern, "min")
else:
mean[key] += einops.reduce(batch[key], pattern, "mean")
max[key] = torch.maximum(max[key], einops.reduce(batch[key], pattern, "max"))
min[key] = torch.minimum(min[key], einops.reduce(batch[key], pattern, "min"))
batch = rb.sample()
for key in self.stats_patterns:
mean[key] /= num_batch
# compute std, min, max
for _ in tqdm.tqdm(range(num_batch)):
batch = rb.sample()
for key, pattern in self.stats_patterns.items():
batch[key] = batch[key].float()
batch_mean = einops.reduce(batch[key], pattern, "mean")
if key not in std:
# first batch initialize std
std[key] = (batch_mean - mean[key]) ** 2
else:
std[key] += (batch_mean - mean[key]) ** 2
max[key] = torch.maximum(max[key], einops.reduce(batch[key], pattern, "max"))
min[key] = torch.minimum(min[key], einops.reduce(batch[key], pattern, "min"))
for key in self.stats_patterns:
std[key] = torch.sqrt(std[key] / num_batch)
stats = TensorDict({}, batch_size=[])
for key in self.stats_patterns:
stats[(*key, "mean")] = mean[key]
stats[(*key, "std")] = std[key]
stats[(*key, "max")] = max[key]
stats[(*key, "min")] = min[key]
if key[0] == "observation":
# use same stats for the next observations
stats[("next", *key)] = stats[key]
return stats