support benchmark without task labels in avalanche.strategies

avalanche/training/templates/base_sgd.py

@@ -1,5 +1,7 @@
 import sys
 from typing import Any, Callable, Generic, Iterable, Sequence, Optional, TypeVar, Union
+
+from torch.utils.data import DataLoader
 from typing_extensions import TypeAlias
 from packaging.version import parse
 
@@ -453,9 +455,15 @@ def make_train_dataloader(
         if "ffcv_args" in kwargs:
             other_dataloader_args["ffcv_args"] = kwargs["ffcv_args"]
 
-        self.dataloader = TaskBalancedDataLoader(
-            self.adapted_dataset, oversample_small_groups=True, **other_dataloader_args
-        )
+        # use task-balanced dataloader for task-aware benchmarks
+        if hasattr(self.experience, "task_labels"):
+            self.dataloader = TaskBalancedDataLoader(
+                self.adapted_dataset,
+                oversample_small_groups=True,
+                **other_dataloader_args
+            )
+        else:
+            self.dataloader = DataLoader(self.adapted_dataset, **other_dataloader_args)
 
     def make_eval_dataloader(
         self,

avalanche/training/templates/problem_type/supervised_problem.py

@@ -35,7 +35,7 @@ def mb_task_id(self):
         """Current mini-batch task labels."""
         mbatch = self.mbatch
         assert mbatch is not None
-        assert len(mbatch) >= 3
+        assert len(mbatch) >= 3, "Task label not found."
         return mbatch[-1]
 
     def criterion(self):
@@ -44,13 +44,16 @@ def criterion(self):
 
     def forward(self):
         """Compute the model's output given the current mini-batch."""
-        return avalanche_forward(self.model, self.mb_x, self.mb_task_id)
+        # use task-aware forward only for task-aware benchmarks
+        if hasattr(self.experience, "task_labels"):
+            return avalanche_forward(self.model, self.mb_x, self.mb_task_id)
+        else:
+            return self.model(self.mb_x)
 
     def _unpack_minibatch(self):
         """Check if the current mini-batch has 3 components."""
         mbatch = self.mbatch
         assert mbatch is not None
-        assert len(mbatch) >= 3
 
         if isinstance(mbatch, tuple):
             mbatch = list(mbatch)

examples/custom_datasets.py

@@ -0,0 +1,97 @@
+################################################################################
+# Copyright (c) 2024 ContinualAI.                                              #
+# Copyrights licensed under the MIT License.                                   #
+# See the accompanying LICENSE file for terms.                                 #
+#                                                                              #
+# Date: 31-05-2024                                                             #
+# Author(s): Antonio Carta                                                     #
+# E-mail: [email protected]                                              #
+# Website: avalanche.continualai.org                                           #
+################################################################################
+
+"""
+An exmaple that shows how to create a class-incremental benchmark from a pytorch dataset.
+"""
+
+import torch
+import argparse
+from torch.nn import CrossEntropyLoss
+from torch.optim import SGD
+from torchvision.transforms import Compose, Normalize, ToTensor
+
+from avalanche.benchmarks.datasets import MNIST, default_dataset_location
+from avalanche.benchmarks.scenarios import class_incremental_benchmark
+from avalanche.benchmarks.utils import (
+    make_avalanche_dataset,
+    TransformGroups,
+    DataAttribute,
+)
+from avalanche.models import SimpleMLP
+from avalanche.training.supervised import Naive
+
+
+def main(args):
+    # Device config
+    device = torch.device(
+        f"cuda:{args.cuda}" if torch.cuda.is_available() and args.cuda >= 0 else "cpu"
+    )
+
+    # create pytorch dataset
+    train_data = MNIST(root=default_dataset_location("mnist"), train=True)
+    test_data = MNIST(root=default_dataset_location("mnist"), train=False)
+
+    # prepare transformations
+    train_transform = Compose([ToTensor(), Normalize((0.1307,), (0.3081,))])
+    eval_transform = Compose([ToTensor(), Normalize((0.1307,), (0.3081,))])
+    tgroups = TransformGroups({"train": train_transform, "eval": eval_transform})
+
+    # create Avalanche datasets with targets attributes (needed to split by class)
+    da = DataAttribute(train_data.targets, "targets")
+    train_data = make_avalanche_dataset(
+        train_data, data_attributes=[da], transform_groups=tgroups
+    )
+
+    da = DataAttribute(test_data.targets, "targets")
+    test_data = make_avalanche_dataset(
+        test_data, data_attributes=[da], transform_groups=tgroups
+    )
+
+    # create benchmark
+    bm = class_incremental_benchmark(
+        {"train": train_data, "test": test_data}, num_experiences=5
+    )
+
+    # Continual learning strategy
+    model = SimpleMLP(num_classes=10)
+    optimizer = SGD(model.parameters(), lr=0.001, momentum=0.9)
+    criterion = CrossEntropyLoss()
+    cl_strategy = Naive(
+        model=model,
+        optimizer=optimizer,
+        criterion=criterion,
+        train_mb_size=32,
+        train_epochs=100,
+        eval_mb_size=32,
+        device=device,
+        eval_every=1,
+    )
+
+    # train and test loop
+    results = []
+    for train_task, test_task in zip(bm.train_stream, bm.test_stream):
+        print("Current Classes: ", train_task.classes_in_this_experience)
+        cl_strategy.train(train_task, eval_streams=[test_task])
+        results.append(cl_strategy.eval(bm.test_stream))
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        "--cuda",
+        type=int,
+        default=0,
+        help="Select zero-indexed cuda device. -1 to use CPU.",
+    )
+    args = parser.parse_args()
+
+    main(args)