| ## @package sampling_train |
| # Module caffe2.python.layers.sampling_train |
| |
| |
| |
| |
| |
| from caffe2.python import schema |
| from caffe2.python.layers.layers import ModelLayer, get_layer_class |
| from caffe2.python.layers.sampling_trainable_mixin import SamplingTrainableMixin |
| |
| |
| class SamplingTrain(ModelLayer): |
| def __init__( |
| self, |
| model, |
| input_record, |
| prediction_layer, |
| output_dims, |
| subtract_log_odd=True, |
| name='sampling_train', |
| **kwargs |
| ): |
| super(SamplingTrain, self).__init__( |
| model, name, input_record, **kwargs |
| ) |
| |
| layer_class = get_layer_class(prediction_layer) |
| assert issubclass(layer_class, SamplingTrainableMixin) |
| |
| assert 'indices' in input_record |
| assert isinstance(input_record.indices, schema.Scalar),\ |
| "input_record.indices is expected to be a schema.Scalar" |
| assert 'input' in input_record |
| |
| self.subtract_log_odd = subtract_log_odd |
| if self.subtract_log_odd: |
| assert 'sampling_prob' in input_record |
| |
| self._prediction_layer = layer_class( |
| model, |
| input_record.input, |
| output_dims=output_dims, |
| **kwargs |
| ) |
| |
| self._prediction_layer.train_param_blobs = [ |
| model.net.NextBlob(str(blob) + '_sampled') |
| for blob in self._prediction_layer.param_blobs |
| ] |
| |
| self.params = self._prediction_layer.params |
| |
| self.output_schema = self._prediction_layer.output_schema |
| |
| def add_ops(self, net): |
| self._prediction_layer.add_ops(net) |
| |
| def add_train_ops(self, net): |
| for full_blob, sampled_blob in zip( |
| self._prediction_layer.param_blobs, |
| self._prediction_layer.train_param_blobs |
| ): |
| net.Gather([full_blob, self.input_record.indices()], sampled_blob) |
| self._prediction_layer.add_train_ops(net) |
| if not self.subtract_log_odd: |
| return |
| log_q = net.Log(self.input_record.sampling_prob(), |
| net.NextScopedBlob("log_q")) |
| net.Sub([self.output_schema(), log_q], self.output_schema(), |
| broadcast=1, use_grad_hack=1) |
