lerobot/lerobot/common/policies/diffusion/model/normalizer.py

359 lines
12 KiB
Python

from typing import Dict, Union
import numpy as np
import torch
import torch.nn as nn
import zarr
from lerobot.common.policies.diffusion.model.dict_of_tensor_mixin import DictOfTensorMixin
from lerobot.common.policies.diffusion.pytorch_utils import dict_apply
class LinearNormalizer(DictOfTensorMixin):
avaliable_modes = ["limits", "gaussian"]
@torch.no_grad()
def fit(
self,
data: Union[Dict, torch.Tensor, np.ndarray, zarr.Array],
last_n_dims=1,
dtype=torch.float32,
mode="limits",
output_max=1.0,
output_min=-1.0,
range_eps=1e-4,
fit_offset=True,
):
if isinstance(data, dict):
for key, value in data.items():
self.params_dict[key] = _fit(
value,
last_n_dims=last_n_dims,
dtype=dtype,
mode=mode,
output_max=output_max,
output_min=output_min,
range_eps=range_eps,
fit_offset=fit_offset,
)
else:
self.params_dict["_default"] = _fit(
data,
last_n_dims=last_n_dims,
dtype=dtype,
mode=mode,
output_max=output_max,
output_min=output_min,
range_eps=range_eps,
fit_offset=fit_offset,
)
def __call__(self, x: Union[Dict, torch.Tensor, np.ndarray]) -> torch.Tensor:
return self.normalize(x)
def __getitem__(self, key: str):
return SingleFieldLinearNormalizer(self.params_dict[key])
def __setitem__(self, key: str, value: "SingleFieldLinearNormalizer"):
self.params_dict[key] = value.params_dict
def _normalize_impl(self, x, forward=True):
if isinstance(x, dict):
result = {}
for key, value in x.items():
params = self.params_dict[key]
result[key] = _normalize(value, params, forward=forward)
return result
else:
if "_default" not in self.params_dict:
raise RuntimeError("Not initialized")
params = self.params_dict["_default"]
return _normalize(x, params, forward=forward)
def normalize(self, x: Union[Dict, torch.Tensor, np.ndarray]) -> torch.Tensor:
return self._normalize_impl(x, forward=True)
def unnormalize(self, x: Union[Dict, torch.Tensor, np.ndarray]) -> torch.Tensor:
return self._normalize_impl(x, forward=False)
def get_input_stats(self) -> Dict:
if len(self.params_dict) == 0:
raise RuntimeError("Not initialized")
if len(self.params_dict) == 1 and "_default" in self.params_dict:
return self.params_dict["_default"]["input_stats"]
result = {}
for key, value in self.params_dict.items():
if key != "_default":
result[key] = value["input_stats"]
return result
def get_output_stats(self, key="_default"):
input_stats = self.get_input_stats()
if "min" in input_stats:
# no dict
return dict_apply(input_stats, self.normalize)
result = {}
for key, group in input_stats.items():
this_dict = {}
for name, value in group.items():
this_dict[name] = self.normalize({key: value})[key]
result[key] = this_dict
return result
class SingleFieldLinearNormalizer(DictOfTensorMixin):
avaliable_modes = ["limits", "gaussian"]
@torch.no_grad()
def fit(
self,
data: Union[torch.Tensor, np.ndarray, zarr.Array],
last_n_dims=1,
dtype=torch.float32,
mode="limits",
output_max=1.0,
output_min=-1.0,
range_eps=1e-4,
fit_offset=True,
):
self.params_dict = _fit(
data,
last_n_dims=last_n_dims,
dtype=dtype,
mode=mode,
output_max=output_max,
output_min=output_min,
range_eps=range_eps,
fit_offset=fit_offset,
)
@classmethod
def create_fit(cls, data: Union[torch.Tensor, np.ndarray, zarr.Array], **kwargs):
obj = cls()
obj.fit(data, **kwargs)
return obj
@classmethod
def create_manual(
cls,
scale: Union[torch.Tensor, np.ndarray],
offset: Union[torch.Tensor, np.ndarray],
input_stats_dict: Dict[str, Union[torch.Tensor, np.ndarray]],
):
def to_tensor(x):
if not isinstance(x, torch.Tensor):
x = torch.from_numpy(x)
x = x.flatten()
return x
# check
for x in [offset] + list(input_stats_dict.values()):
assert x.shape == scale.shape
assert x.dtype == scale.dtype
params_dict = nn.ParameterDict(
{
"scale": to_tensor(scale),
"offset": to_tensor(offset),
"input_stats": nn.ParameterDict(dict_apply(input_stats_dict, to_tensor)),
}
)
return cls(params_dict)
@classmethod
def create_identity(cls, dtype=torch.float32):
scale = torch.tensor([1], dtype=dtype)
offset = torch.tensor([0], dtype=dtype)
input_stats_dict = {
"min": torch.tensor([-1], dtype=dtype),
"max": torch.tensor([1], dtype=dtype),
"mean": torch.tensor([0], dtype=dtype),
"std": torch.tensor([1], dtype=dtype),
}
return cls.create_manual(scale, offset, input_stats_dict)
def normalize(self, x: Union[torch.Tensor, np.ndarray]) -> torch.Tensor:
return _normalize(x, self.params_dict, forward=True)
def unnormalize(self, x: Union[torch.Tensor, np.ndarray]) -> torch.Tensor:
return _normalize(x, self.params_dict, forward=False)
def get_input_stats(self):
return self.params_dict["input_stats"]
def get_output_stats(self):
return dict_apply(self.params_dict["input_stats"], self.normalize)
def __call__(self, x: Union[torch.Tensor, np.ndarray]) -> torch.Tensor:
return self.normalize(x)
def _fit(
data: Union[torch.Tensor, np.ndarray, zarr.Array],
last_n_dims=1,
dtype=torch.float32,
mode="limits",
output_max=1.0,
output_min=-1.0,
range_eps=1e-4,
fit_offset=True,
):
assert mode in ["limits", "gaussian"]
assert last_n_dims >= 0
assert output_max > output_min
# convert data to torch and type
if isinstance(data, zarr.Array):
data = data[:]
if isinstance(data, np.ndarray):
data = torch.from_numpy(data)
if dtype is not None:
data = data.type(dtype)
# convert shape
dim = 1
if last_n_dims > 0:
dim = np.prod(data.shape[-last_n_dims:])
data = data.reshape(-1, dim)
# compute input stats min max mean std
input_min, _ = data.min(axis=0)
input_max, _ = data.max(axis=0)
input_mean = data.mean(axis=0)
input_std = data.std(axis=0)
# compute scale and offset
if mode == "limits":
if fit_offset:
# unit scale
input_range = input_max - input_min
ignore_dim = input_range < range_eps
input_range[ignore_dim] = output_max - output_min
scale = (output_max - output_min) / input_range
offset = output_min - scale * input_min
offset[ignore_dim] = (output_max + output_min) / 2 - input_min[ignore_dim]
# ignore dims scaled to mean of output max and min
else:
# use this when data is pre-zero-centered.
assert output_max > 0
assert output_min < 0
# unit abs
output_abs = min(abs(output_min), abs(output_max))
input_abs = torch.maximum(torch.abs(input_min), torch.abs(input_max))
ignore_dim = input_abs < range_eps
input_abs[ignore_dim] = output_abs
# don't scale constant channels
scale = output_abs / input_abs
offset = torch.zeros_like(input_mean)
elif mode == "gaussian":
ignore_dim = input_std < range_eps
scale = input_std.clone()
scale[ignore_dim] = 1
scale = 1 / scale
offset = -input_mean * scale if fit_offset else torch.zeros_like(input_mean)
# save
this_params = nn.ParameterDict(
{
"scale": scale,
"offset": offset,
"input_stats": nn.ParameterDict(
{"min": input_min, "max": input_max, "mean": input_mean, "std": input_std}
),
}
)
for p in this_params.parameters():
p.requires_grad_(False)
return this_params
def _normalize(x, params, forward=True):
assert "scale" in params
if isinstance(x, np.ndarray):
x = torch.from_numpy(x)
scale = params["scale"]
offset = params["offset"]
x = x.to(device=scale.device, dtype=scale.dtype)
src_shape = x.shape
x = x.reshape(-1, scale.shape[0])
x = x * scale + offset if forward else (x - offset) / scale
x = x.reshape(src_shape)
return x
def test():
data = torch.zeros((100, 10, 9, 2)).uniform_()
data[..., 0, 0] = 0
normalizer = SingleFieldLinearNormalizer()
normalizer.fit(data, mode="limits", last_n_dims=2)
datan = normalizer.normalize(data)
assert datan.shape == data.shape
assert np.allclose(datan.max(), 1.0)
assert np.allclose(datan.min(), -1.0)
dataun = normalizer.unnormalize(datan)
assert torch.allclose(data, dataun, atol=1e-7)
_ = normalizer.get_input_stats()
_ = normalizer.get_output_stats()
normalizer = SingleFieldLinearNormalizer()
normalizer.fit(data, mode="limits", last_n_dims=1, fit_offset=False)
datan = normalizer.normalize(data)
assert datan.shape == data.shape
assert np.allclose(datan.max(), 1.0, atol=1e-3)
assert np.allclose(datan.min(), 0.0, atol=1e-3)
dataun = normalizer.unnormalize(datan)
assert torch.allclose(data, dataun, atol=1e-7)
data = torch.zeros((100, 10, 9, 2)).uniform_()
normalizer = SingleFieldLinearNormalizer()
normalizer.fit(data, mode="gaussian", last_n_dims=0)
datan = normalizer.normalize(data)
assert datan.shape == data.shape
assert np.allclose(datan.mean(), 0.0, atol=1e-3)
assert np.allclose(datan.std(), 1.0, atol=1e-3)
dataun = normalizer.unnormalize(datan)
assert torch.allclose(data, dataun, atol=1e-7)
# dict
data = torch.zeros((100, 10, 9, 2)).uniform_()
data[..., 0, 0] = 0
normalizer = LinearNormalizer()
normalizer.fit(data, mode="limits", last_n_dims=2)
datan = normalizer.normalize(data)
assert datan.shape == data.shape
assert np.allclose(datan.max(), 1.0)
assert np.allclose(datan.min(), -1.0)
dataun = normalizer.unnormalize(datan)
assert torch.allclose(data, dataun, atol=1e-7)
_ = normalizer.get_input_stats()
_ = normalizer.get_output_stats()
data = {
"obs": torch.zeros((1000, 128, 9, 2)).uniform_() * 512,
"action": torch.zeros((1000, 128, 2)).uniform_() * 512,
}
normalizer = LinearNormalizer()
normalizer.fit(data)
datan = normalizer.normalize(data)
dataun = normalizer.unnormalize(datan)
for key in data:
assert torch.allclose(data[key], dataun[key], atol=1e-4)
_ = normalizer.get_input_stats()
_ = normalizer.get_output_stats()
state_dict = normalizer.state_dict()
n = LinearNormalizer()
n.load_state_dict(state_dict)
datan = n.normalize(data)
dataun = n.unnormalize(datan)
for key in data:
assert torch.allclose(data[key], dataun[key], atol=1e-4)