make unit tests pass

examples/1_load_hugging_face_dataset.py

@@ -44,7 +44,7 @@ from datasets import load_dataset
 # TODO(rcadene): list available datasets on lerobot page using `datasets`
 
 # download/load hugging face dataset in pyarrow format
-hf_dataset, fps = load_dataset("lerobot/pusht", split="train"), 10
+hf_dataset, fps = load_dataset("lerobot/pusht", split="train", revision="v1.1"), 10
 
 # display name of dataset and its features
 # TODO(rcadene): update to make the print pretty

examples/4_train_policy.py

@@ -34,7 +34,7 @@ dataset = make_dataset(hydra_cfg)
 # If you're doing something different, you will likely need to change at least some of the defaults.
 cfg = DiffusionConfig()
 # TODO(alexander-soare): Remove LR scheduler from the policy.
-policy = DiffusionPolicy(cfg, lr_scheduler_num_training_steps=training_steps)
+policy = DiffusionPolicy(cfg, lr_scheduler_num_training_steps=training_steps, dataset_stats=dataset.stats)
 policy.train()
 policy.to(device)
 

lerobot/common/datasets/factory.py

@@ -2,6 +2,7 @@ import os
 from pathlib import Path
 
 import torch
+from omegaconf import OmegaConf
 
 DATA_DIR = Path(os.environ["DATA_DIR"]) if "DATA_DIR" in os.environ else None
 
@@ -43,7 +44,10 @@ def make_dataset(
     )
 
     if cfg.get("override_dataset_stats"):
-        for key, val in cfg.override_dataset_stats.items():
+        for key, stats_dict in cfg.override_dataset_stats.items():
-            dataset.stats[key] = torch.tensor(val)
+            for stats_type, listconfig in stats_dict.items():
+                # example of stats_type: min, max, mean, std
+                stats = OmegaConf.to_container(listconfig, resolve=True)
+                dataset.stats[key][stats_type] = torch.tensor(stats, dtype=torch.float32)
 
     return dataset

lerobot/common/envs/utils.py

@@ -22,7 +22,7 @@ def preprocess_observation(observation):
         assert img.dtype == torch.uint8, f"expect torch.uint8, but instead {img.dtype=}"
 
         # convert to channel first of type float32 in range [0,1]
-        img = einops.rearrange(img, "b h w c -> b c h w")
+        img = einops.rearrange(img, "b h w c -> b c h w").contiguous()
         img = img.type(torch.float32)
         img /= 255
 

lerobot/common/policies/act/configuration_act.py

@@ -1,4 +1,4 @@
-from dataclasses import dataclass
+from dataclasses import dataclass, field
 
 
 @dataclass
@@ -61,13 +61,17 @@ class ActionChunkingTransformerConfig:
     n_action_steps: int = 100
 
     # Normalization / Unnormalization
-    normalize_input_modes: dict[str, str] = {
+    normalize_input_modes: dict[str, str] = field(
-        "observation.image": "mean_std",
+        default_factory=lambda: {
-        "observation.state": "mean_std",
+            "observation.image": "mean_std",
-    }
+            "observation.state": "mean_std",
-    unnormalize_output_modes: dict[str, str] = {
+        }
-        "action": "mean_std",
+    )
-    }
+    unnormalize_output_modes: dict[str, str] = field(
+        default_factory=lambda: {
+            "action": "mean_std",
+        }
+    )
     # Architecture.
     # Vision backbone.
     vision_backbone: str = "resnet18"

lerobot/common/policies/act/modeling_act.py

@@ -22,6 +22,7 @@ from torchvision.ops.misc import FrozenBatchNorm2d
 from lerobot.common.policies.act.configuration_act import ActionChunkingTransformerConfig
 from lerobot.common.policies.utils import (
     normalize_inputs,
+    to_buffer_dict,
     unnormalize_outputs,
 )
 
@@ -75,7 +76,7 @@ class ActionChunkingTransformerPolicy(nn.Module):
         if cfg is None:
             cfg = ActionChunkingTransformerConfig()
         self.cfg = cfg
-        self.register_buffer("dataset_stats", dataset_stats)
+        self.dataset_stats = to_buffer_dict(dataset_stats)
         self.normalize_input_modes = cfg.normalize_input_modes
         self.unnormalize_output_modes = cfg.unnormalize_output_modes
 
@@ -179,7 +180,12 @@ class ActionChunkingTransformerPolicy(nn.Module):
             # `_forward` returns a (batch_size, n_action_steps, action_dim) tensor, but the queue effectively
             # has shape (n_action_steps, batch_size, *), hence the transpose.
             actions = self._forward(batch)[0][: self.cfg.n_action_steps]
-            actions = unnormalize_outputs(actions, self.dataset_stats, self.unnormalize_output_modes)
+
+            # TODO(rcadene): make _forward return output dictionary?
+            out_dict = {"action": actions}
+            out_dict = unnormalize_outputs(out_dict, self.dataset_stats, self.unnormalize_output_modes)
+            actions = out_dict["action"]
+
             self._action_queue.extend(actions.transpose(0, 1))
         return self._action_queue.popleft()
 
@@ -214,7 +220,7 @@ class ActionChunkingTransformerPolicy(nn.Module):
 
         batch = normalize_inputs(batch, self.dataset_stats, self.normalize_input_modes)
         loss_dict = self.forward(batch)
-        # TODO(rcadene): unnormalize_outputs(actions, self.dataset_stats, self.unnormalize_output_modes)
+        # TODO(rcadene): unnormalize_outputs(out_dict, self.dataset_stats, self.unnormalize_output_modes)
         loss = loss_dict["loss"]
         loss.backward()
 

lerobot/common/policies/diffusion/configuration_diffusion.py

@@ -1,4 +1,4 @@
-from dataclasses import dataclass
+from dataclasses import dataclass, field
 
 
 @dataclass
@@ -70,13 +70,17 @@ class DiffusionConfig:
     n_action_steps: int = 8
 
     # Normalization / Unnormalization
-    normalize_input_modes: dict[str, str] = {
+    normalize_input_modes: dict[str, str] = field(
-        "observation.image": "mean_std",
+        default_factory=lambda: {
-        "observation.state": "min_max",
+            "observation.image": "mean_std",
-    }
+            "observation.state": "min_max",
-    unnormalize_output_modes: dict[str, str] = {
+        }
-        "action": "min_max",
+    )
-    }
+    unnormalize_output_modes: dict[str, str] = field(
+        default_factory=lambda: {
+            "action": "min_max",
+        }
+    )
 
     # Architecture / modeling.
     # Vision backbone.

lerobot/common/policies/diffusion/modeling_diffusion.py

@@ -31,6 +31,7 @@ from lerobot.common.policies.utils import (
     get_dtype_from_parameters,
     normalize_inputs,
     populate_queues,
+    to_buffer_dict,
     unnormalize_outputs,
 )
 
@@ -57,7 +58,7 @@ class DiffusionPolicy(nn.Module):
         if cfg is None:
             cfg = DiffusionConfig()
         self.cfg = cfg
-        self.register_buffer("dataset_stats", dataset_stats)
+        self.dataset_stats = to_buffer_dict(dataset_stats)
         self.normalize_input_modes = cfg.normalize_input_modes
         self.unnormalize_output_modes = cfg.unnormalize_output_modes
 
@@ -144,7 +145,11 @@ class DiffusionPolicy(nn.Module):
             else:
                 actions = self.diffusion.generate_actions(batch)
 
-            actions = unnormalize_outputs(actions, self.dataset_stats, self.unnormalize_output_modes)
+            # TODO(rcadene): make above methods return output dictionary?
+            out_dict = {"action": actions}
+            out_dict = unnormalize_outputs(out_dict, self.dataset_stats, self.unnormalize_output_modes)
+            actions = out_dict["action"]
+
             self._queues["action"].extend(actions.transpose(0, 1))
 
         action = self._queues["action"].popleft()
@@ -166,7 +171,7 @@ class DiffusionPolicy(nn.Module):
         loss = self.forward(batch)["loss"]
         loss.backward()
 
-        # TODO(rcadene): unnormalize_outputs(actions, self.dataset_stats, self.unnormalize_output_modes)
+        # TODO(rcadene): unnormalize_outputs(out_dict, self.dataset_stats, self.unnormalize_output_modes)
 
         grad_norm = torch.nn.utils.clip_grad_norm_(
             self.diffusion.parameters(),

lerobot/common/policies/utils.py

@@ -66,3 +66,20 @@ def unnormalize_outputs(batch, stats, unnormalize_output_modes):
         else:
             raise ValueError(mode)
     return batch
+
+
+def to_buffer_dict(dataset_stats):
+    # TODO(rcadene): replace this function by `torch.BufferDict` when it exists
+    # see: https://github.com/pytorch/pytorch/issues/37386
+    # TODO(rcadene): make `to_buffer_dict` generic and add docstring
+    if dataset_stats is None:
+        return None
+
+    new_ds_stats = {}
+    for key, stats_dict in dataset_stats.items():
+        new_stats_dict = {}
+        for stats_type, value in stats_dict.items():
+            # set requires_grad=False to have the same behavior as a nn.Buffer
+            new_stats_dict[stats_type] = nn.Parameter(value, requires_grad=False)
+        new_ds_stats[key] = nn.ParameterDict(new_stats_dict)
+    return nn.ParameterDict(new_ds_stats)

lerobot/configs/policy/act.yaml

@@ -12,7 +12,8 @@ n_obs_steps: 1
 # when temporal_agg=False, n_action_steps=horizon
 
 override_dataset_stats:
-  observation.image:
+  observation.images.top:
+    # stats from imagenet, since we use a pretrained vision model
     mean: [[[0.485]], [[0.456]], [[0.406]]]  # (c,1,1)
     std: [[[0.229]], [[0.224]], [[0.225]]]  # (c,1,1)
 
@@ -35,7 +36,7 @@ policy:
 
   # Normalization / Unnormalization
   normalize_input_modes:
-    observation.image: mean_std
+    observation.images.top: mean_std
     observation.state: mean_std
   unnormalize_output_modes:
     action: mean_std

lerobot/configs/policy/diffusion.yaml

@@ -19,9 +19,12 @@ online_steps: 0
 offline_prioritized_sampler: true
 
 override_dataset_stats:
+  # TODO(rcadene, alexander-soare): should we remove image stats as well? do we use a pretrained vision model?
   observation.image:
     mean: [[[0.5]], [[0.5]], [[0.5]]]  # (c,1,1)
     std: [[[0.5]], [[0.5]], [[0.5]]]  # (c,1,1)
+  # TODO(rcadene, alexander-soare): we override state and action stats to use the same as the pretrained model
+  # from the original codebase, but we should remove these and train our own pretrained model
   observation.state:
     min: [13.456424, 32.938293]
     max: [496.14618, 510.9579]

lerobot/scripts/visualize_dataset.py

@@ -50,11 +50,7 @@ def visualize_dataset(cfg: dict, out_dir=None):
     log_output_dir(out_dir)
 
     logging.info("make_dataset")
-    dataset = make_dataset(
+    dataset = make_dataset(cfg)
-        cfg,
-        # remove all transformations such as rescale images from [0,255] to [0,1] or normalization
-        normalize=False,
-    )
 
     logging.info("Start rendering episodes from offline buffer")
     video_paths = render_dataset(dataset, out_dir, MAX_NUM_STEPS * NUM_EPISODES_TO_RENDER)

tests/test_envs.py

@@ -6,7 +6,6 @@ import torch
 from gymnasium.utils.env_checker import check_env
 
 import lerobot
-from lerobot.common.datasets.factory import make_dataset
 from lerobot.common.envs.factory import make_env
 from lerobot.common.envs.utils import preprocess_observation
 from lerobot.common.utils.utils import init_hydra_config
@@ -38,12 +37,14 @@ def test_factory(env_name):
         overrides=[f"env={env_name}", f"device={DEVICE}"],
     )
 
-    dataset = make_dataset(cfg)
-
     env = make_env(cfg, num_parallel_envs=1)
     obs, _ = env.reset()
     obs = preprocess_observation(obs)
-    for key in dataset.image_keys:
+
+    # test image keys are float32 in range [0,1]
+    for key in obs:
+        if "image" not in key:
+            continue
         img = obs[key]
         assert img.dtype == torch.float32
         # TODO(rcadene): we assume for now that image normalization takes place in the model