added no head (#218)

Author: ravinkohli

autoPyTorch/pipeline/components/setup/network_head/no_head.py

@@ -0,0 +1,52 @@
+from typing import Any, Dict, Optional, Tuple, Union
+
+from ConfigSpace.configuration_space import ConfigurationSpace
+from ConfigSpace.hyperparameters import CategoricalHyperparameter
+
+import numpy as np
+
+from torch import nn
+
+from autoPyTorch.pipeline.components.setup.network_head.base_network_head import NetworkHeadComponent
+from autoPyTorch.pipeline.components.setup.network_head.utils import _activations
+from autoPyTorch.utils.common import HyperparameterSearchSpace, add_hyperparameter
+
+
+class NoHead(NetworkHeadComponent):
+    """
+    Head which only adds a fully connected layer which takes the
+    output of the backbone as input and outputs the predictions.
+    Flattens any input in a array of shape [B, prod(input_shape)].
+    """
+
+    def build_head(self, input_shape: Tuple[int, ...], output_shape: Tuple[int, ...]) -> nn.Module:
+        layers = [nn.Flatten()]
+        in_features = np.prod(input_shape).item()
+        out_features = np.prod(output_shape).item()
+        layers.append(_activations[self.config["activation"]]())
+        layers.append(nn.Linear(in_features=in_features,
+                                out_features=out_features))
+        return nn.Sequential(*layers)
+
+    @staticmethod
+    def get_properties(dataset_properties: Optional[Dict[str, Any]] = None) -> Dict[str, Union[str, bool]]:
+        return {
+            'shortname': 'NoHead',
+            'name': 'NoHead',
+            'handles_tabular': True,
+            'handles_image': True,
+            'handles_time_series': True,
+        }
+
+    @staticmethod
+    def get_hyperparameter_search_space(
+        dataset_properties: Optional[Dict[str, str]] = None,
+        activation: HyperparameterSearchSpace = HyperparameterSearchSpace(hyperparameter="activation",
+                                                                          value_range=tuple(_activations.keys()),
+                                                                          default_value=list(_activations.keys())[0]),
+    ) -> ConfigurationSpace:
+        cs = ConfigurationSpace()
+
+        add_hyperparameter(cs, activation, CategoricalHyperparameter)
+
+        return cs

test/test_pipeline/components/setup/test_setup_networks.py

@@ -14,7 +14,7 @@ def backbone(request):
     return request.param
 
 
-@pytest.fixture(params=['fully_connected'])
+@pytest.fixture(params=['fully_connected', 'no_head'])
 def head(request):
     return request.param