Default learning rate to None (default lr for the optimizer)

CHANGELOG.md

@@ -32,6 +32,8 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 
 - Renamed `ClassificationInput` to `ClassificationInputMixin` ([#1116](https://github.com/PyTorchLightning/lightning-flash/pull/1116))
 
+- Changed the default `learning_rate` for all tasks to be `None`, corresponding to the default for your chosen optimizer ([#1172](https://github.com/PyTorchLightning/lightning-flash/pull/1172))
+
 ### Deprecated
 
 ### Fixed

flash/audio/speech_recognition/model.py

@@ -57,7 +57,7 @@ def __init__(
         processor_backbone: str = None,
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
-        learning_rate: float = 1e-5,
+        learning_rate: Optional[float] = None,
     ):
         os.environ["TOKENIZERS_PARALLELISM"] = "TRUE"
         # disable HF thousand warnings

flash/core/model.py

@@ -283,7 +283,8 @@ class Task(DatasetProcessor, ModuleWrapperBase, LightningModule, FineTuningHooks
     Args:
         model: Model to use for the task.
         loss_fn: Loss function for training.
-        learning_rate: Learning rate to use for training, defaults to ``5e-5``.
+        learning_rate: Learning rate to use for training. If ``None`` (the default) then the default LR for your chosen
+            optimizer will be used.
         optimizer: Optimizer to use for training.
         lr_scheduler: The LR scheduler to use during training.
         metrics: Metrics to compute for training and evaluation. Can either be an metric from the `torchmetrics`
@@ -305,7 +306,7 @@ def __init__(
         self,
         model: MODEL_TYPE = None,
         loss_fn: LOSS_FN_TYPE = None,
-        learning_rate: float = 5e-5,
+        learning_rate: Optional[float] = None,
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
         metrics: METRICS_TYPE = None,
@@ -458,12 +459,11 @@ def _get_optimizer_class_from_registry(self, optimizer_key: str) -> Optimizer:
 
     def configure_optimizers(self) -> Union[Optimizer, Tuple[List[Optimizer], List[_LRScheduler]]]:
         """Implement how optimizer and optionally learning rate schedulers should be configured."""
+        optimizers_kwargs: Dict[str, Any] = {}
         if isinstance(self.optimizer, str):
             optimizer_fn = self._get_optimizer_class_from_registry(self.optimizer.lower())
-            optimizers_kwargs: Dict[str, Any] = {"lr": self.learning_rate}
         elif isinstance(self.optimizer, Callable):
             optimizer_fn = self.optimizer
-            optimizers_kwargs: Dict[str, Any] = {"lr": self.learning_rate}
         elif isinstance(self.optimizer, Tuple):
             if len(self.optimizer) != 2:
                 raise MisconfigurationException(
@@ -485,13 +485,15 @@ def configure_optimizers(self) -> Union[Optimizer, Tuple[List[Optimizer], List[_
 
             optimizer_fn: Callable = self._get_optimizer_class_from_registry(self.optimizer[0])
             optimizers_kwargs: Dict[str, Any] = self.optimizer[1]
-            optimizers_kwargs["lr"] = self.learning_rate
         else:
             raise TypeError(
                 f"""Optimizer should be of type string or callable or tuple(string, dictionary)
                 but got {type(self.optimizer)}."""
             )
 
+        if self.learning_rate is not None:
+            optimizers_kwargs["lr"] = self.learning_rate
+
         model_parameters = filter(lambda p: p.requires_grad, self.parameters())
         optimizer: Optimizer = optimizer_fn(model_parameters, **optimizers_kwargs)
         if self.lr_scheduler is not None:

flash/core/optimizers/optimizers.py

@@ -1,3 +1,4 @@
+from functools import partial
 from inspect import isclass
 from typing import Callable, List
 
@@ -17,7 +18,16 @@
             _optimizers.append(_optimizer)
 
     for fn in _optimizers:
-        _OPTIMIZERS_REGISTRY(fn, name=fn.__name__.lower())
+        name = fn.__name__.lower()
+        if name == "sgd":
+
+            def wrapper(fn, parameters, lr=None, **kwargs):
+                if lr is None:
+                    raise TypeError("The `learning_rate` argument is required when the optimizer is SGD.")
+                return fn(parameters, lr, **kwargs)
+
+            fn = partial(wrapper, fn)
+        _OPTIMIZERS_REGISTRY(fn, name=name)
 
 
 if _TORCH_OPTIMIZER_AVAILABLE:

flash/graph/classification/model.py

@@ -66,7 +66,7 @@ def __init__(
         pooling_fn: Optional[Union[str, Callable]] = "mean",
         head: Optional[Union[Callable, nn.Module]] = None,
         loss_fn: LOSS_FN_TYPE = F.cross_entropy,
-        learning_rate: float = 1e-3,
+        learning_rate: Optional[float] = None,
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
         metrics: METRICS_TYPE = None,

flash/image/classification/model.py

@@ -97,7 +97,7 @@ def __init__(
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
         metrics: METRICS_TYPE = None,
-        learning_rate: float = 1e-3,
+        learning_rate: Optional[float] = None,
         multi_label: bool = False,
         training_strategy: Optional[str] = "default",
         training_strategy_kwargs: Optional[Dict[str, Any]] = None,

flash/image/detection/model.py

@@ -52,7 +52,7 @@ def __init__(
         pretrained: bool = True,
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
-        learning_rate: float = 1e-2,
+        learning_rate: Optional[float] = None,
         predict_kwargs: Dict = None,
         **kwargs: Any,
     ):

flash/image/embedding/model.py

@@ -74,7 +74,7 @@ def __init__(
         pretrained: bool = False,
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
-        learning_rate: float = 1e-3,
+        learning_rate: Optional[float] = None,
         backbone_kwargs: Optional[Dict[str, Any]] = None,
         training_strategy_kwargs: Optional[Dict[str, Any]] = None,
         pretraining_transform_kwargs: Optional[Dict[str, Any]] = None,

flash/image/face_detection/model.py

@@ -11,7 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-from typing import Any, Iterable, List, Union
+from typing import Any, Iterable, List, Optional, Union
 
 import torch
 from torch.nn import Module
@@ -54,7 +54,7 @@ def __init__(
         metrics: METRICS_TYPE = None,
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
-        learning_rate: float = 1e-4,
+        learning_rate: Optional[float] = None,
         **kwargs: Any,
     ):
         self.save_hyperparameters()

flash/image/instance_segmentation/model.py

@@ -48,7 +48,7 @@ def __init__(
         pretrained: bool = True,
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
-        learning_rate: float = 5e-4,
+        learning_rate: Optional[float] = None,
         output_transform: OUTPUT_TRANSFORM_TYPE = InstanceSegmentationOutputTransform(),
         predict_kwargs: Dict = None,
         **kwargs: Any,

flash/image/keypoint_detection/model.py

@@ -49,7 +49,7 @@ def __init__(
         pretrained: bool = True,
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
-        learning_rate: float = 5e-4,
+        learning_rate: Optional[float] = None,
         predict_kwargs: Dict = None,
         **kwargs: Any,
     ):

flash/image/segmentation/model.py

@@ -75,7 +75,8 @@ class SemanticSegmentation(ClassificationTask):
             package, a custom metric inherenting from `torchmetrics.Metric`, a callable function or a list/dict
             containing a combination of the aforementioned. In all cases, each metric needs to have the signature
             `metric(preds,target)` and return a single scalar tensor. Defaults to :class:`torchmetrics.IOU`.
-        learning_rate: Learning rate to use for training.
+        learning_rate: Learning rate to use for training. If ``None`` (the default) then the default LR for your chosen
+            optimizer will be used.
         multi_label: Whether the targets are multi-label or not.
         output: The :class:`~flash.core.data.io.output.Output` to use when formatting prediction outputs.
         output_transform: :class:`~flash.core.data.io.output_transform.OutputTransform` use for post processing samples.
@@ -101,7 +102,7 @@ def __init__(
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
         metrics: METRICS_TYPE = None,
-        learning_rate: float = 1e-3,
+        learning_rate: Optional[float] = None,
         multi_label: bool = False,
         output_transform: OUTPUT_TRANSFORM_TYPE = None,
     ) -> None:

flash/image/style_transfer/model.py

@@ -78,7 +78,7 @@ def __init__(
         style_weight: float = 1e10,
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
-        learning_rate: float = 1e-3,
+        learning_rate: Optional[float] = None,
     ):
         self.save_hyperparameters(ignore="style_image")
 

flash/pointcloud/detection/model.py

@@ -60,7 +60,7 @@ def __init__(
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
         metrics: METRICS_TYPE = None,
-        learning_rate: float = 1e-2,
+        learning_rate: Optional[float] = None,
         lambda_loss_cls: float = 1.0,
         lambda_loss_bbox: float = 1.0,
         lambda_loss_dir: float = 1.0,

flash/pointcloud/segmentation/model.py

@@ -69,7 +69,7 @@ def __init__(
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
         metrics: METRICS_TYPE = None,
-        learning_rate: float = 1e-2,
+        learning_rate: Optional[float] = None,
         multi_label: bool = False,
     ):
         import flash

flash/tabular/classification/model.py

@@ -67,7 +67,7 @@ def __init__(
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
         metrics: METRICS_TYPE = None,
-        learning_rate: float = 5e-4,
+        learning_rate: Optional[float] = None,
         **backbone_kwargs,
     ):
         self.save_hyperparameters()

flash/tabular/forecasting/model.py

@@ -35,7 +35,7 @@ def __init__(
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
         metrics: Union[torchmetrics.Metric, List[torchmetrics.Metric]] = None,
-        learning_rate: float = 4e-3,
+        learning_rate: Optional[float] = None,
     ):
         self.save_hyperparameters()
 

flash/tabular/regression/model.py

@@ -64,7 +64,7 @@ def __init__(
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
         metrics: METRICS_TYPE = None,
-        learning_rate: float = 1e-2,
+        learning_rate: Optional[float] = None,
         **backbone_kwargs
     ):
         self.save_hyperparameters()

flash/template/classification/model.py

@@ -55,7 +55,7 @@ def __init__(
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
         metrics: METRICS_TYPE = None,
-        learning_rate: float = 1e-2,
+        learning_rate: Optional[float] = None,
         multi_label: bool = False,
     ):
         self.save_hyperparameters()

flash/text/classification/model.py

@@ -75,7 +75,7 @@ def __init__(
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
         metrics: METRICS_TYPE = None,
-        learning_rate: float = 1e-2,
+        learning_rate: Optional[float] = None,
         multi_label: bool = False,
         enable_ort: bool = False,
     ):

flash/text/question_answering/model.py

@@ -104,7 +104,7 @@ def __init__(
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
         metrics: METRICS_TYPE = None,
-        learning_rate: float = 5e-5,
+        learning_rate: Optional[float] = None,
         enable_ort: bool = False,
         n_best_size: int = 20,
         version_2_with_negative: bool = True,

flash/text/seq2seq/core/model.py

@@ -100,7 +100,7 @@ def __init__(
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
         metrics: METRICS_TYPE = None,
-        learning_rate: float = 5e-5,
+        learning_rate: Optional[float] = None,
         num_beams: Optional[int] = None,
         enable_ort: bool = False,
         output_transform: Optional[OutputTransform] = None,

flash/text/seq2seq/summarization/model.py

@@ -56,7 +56,7 @@ def __init__(
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
         metrics: METRICS_TYPE = None,
-        learning_rate: float = 1e-5,
+        learning_rate: Optional[float] = None,
         num_beams: Optional[int] = 4,
         use_stemmer: bool = True,
         enable_ort: bool = False,

flash/text/seq2seq/translation/model.py

@@ -11,7 +11,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-from typing import Any, Dict, List, Optional, Union
+from typing import Any, Dict, Optional, Union
 
 from torchmetrics import BLEUScore
 
@@ -56,7 +56,7 @@ def __init__(
         optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
         metrics: METRICS_TYPE = None,
-        learning_rate: float = 1e-5,
+        learning_rate: Optional[float] = None,
         num_beams: Optional[int] = 4,
         n_gram: bool = 4,
         smooth: bool = True,
@@ -99,8 +99,3 @@ def compute_metrics(self, generated_tokens, batch, prefix):
         else:
             result = self.bleu(reference_corpus, translate_corpus)
         self.log(f"{prefix}_bleu_score", result, on_step=False, on_epoch=True, prog_bar=True)
-
-    @staticmethod
-    def _ci_benchmark_fn(history: List[Dict[str, Any]]):
-        """This function is used only for debugging usage with CI."""
-        assert history[-1]["val_bleu_score"] > 0.6, history[-1]["val_bleu_score"]

flash/video/classification/model.py

@@ -77,10 +77,10 @@ def __init__(
         backbone_kwargs: Optional[Dict] = None,
         pretrained: bool = True,
         loss_fn: LOSS_FN_TYPE = F.cross_entropy,
-        optimizer: OPTIMIZER_TYPE = "SGD",
+        optimizer: OPTIMIZER_TYPE = "Adam",
         lr_scheduler: LR_SCHEDULER_TYPE = None,
         metrics: METRICS_TYPE = Accuracy(),
-        learning_rate: float = 1e-3,
+        learning_rate: Optional[float] = None,
         head: Optional[Union[FunctionType, nn.Module]] = None,
     ):
         self.save_hyperparameters()

tests/core/test_model.py

@@ -17,6 +17,8 @@
 from itertools import chain
 from numbers import Number
 from typing import Any, Tuple
+from unittest import mock
+from unittest.mock import MagicMock
 
 import pytest
 import pytorch_lightning as pl
@@ -29,6 +31,7 @@
 from torchmetrics import Accuracy
 
 import flash
+from flash import Task
 from flash.audio import SpeechRecognition
 from flash.core.adapter import Adapter
 from flash.core.classification import ClassificationTask
@@ -357,6 +360,26 @@ def test_optimizers_and_schedulers(tmpdir, optim, sched, interval):
     trainer.fit(task, train_dl)
 
 
+def test_optimizer_learning_rate():
+    mock_optimizer = MagicMock()
+    Task.optimizers(mock_optimizer, "test")
+
+    model = nn.Sequential(nn.Flatten(), nn.Linear(28 * 28, 10), nn.LogSoftmax())
+
+    ClassificationTask(model, optimizer="test").configure_optimizers()
+    mock_optimizer.assert_called_once_with(mock.ANY)
+
+    mock_optimizer.reset_mock()
+
+    ClassificationTask(model, optimizer="test", learning_rate=10).configure_optimizers()
+    mock_optimizer.assert_called_once_with(mock.ANY, lr=10)
+
+    mock_optimizer.reset_mock()
+
+    with pytest.raises(TypeError, match="The `learning_rate` argument is required"):
+        ClassificationTask(model, optimizer="sgd").configure_optimizers()
+
+
 @pytest.mark.skipif(not _TORCH_OPTIMIZER_AVAILABLE, reason="torch_optimizer isn't installed.")
 @pytest.mark.parametrize("optim", ["Yogi"])
 def test_external_optimizers_torch_optimizer(tmpdir, optim):