def evaluate()

in evaluations/evaluator.py [0:0]

• 28 lines of code
• 4 McCabe index (conditional complexity)

    def evaluate(self, features: np.ndarray, radii: np.ndarray, eval_features: np.ndarray):
        """
        Evaluate if new feature vectors are at the manifold.
        """
        num_eval_images = eval_features.shape[0]
        num_ref_images = radii.shape[0]
        distance_batch = np.zeros([self.row_batch_size, num_ref_images], dtype=np.float32)
        batch_predictions = np.zeros([num_eval_images, self.num_nhoods], dtype=np.int32)
        max_realism_score = np.zeros([num_eval_images], dtype=np.float32)
        nearest_indices = np.zeros([num_eval_images], dtype=np.int32)

        for begin1 in range(0, num_eval_images, self.row_batch_size):
            end1 = min(begin1 + self.row_batch_size, num_eval_images)
            feature_batch = eval_features[begin1:end1]

            for begin2 in range(0, num_ref_images, self.col_batch_size):
                end2 = min(begin2 + self.col_batch_size, num_ref_images)
                ref_batch = features[begin2:end2]

                distance_batch[
                    0 : end1 - begin1, begin2:end2
                ] = self.distance_block.pairwise_distances(feature_batch, ref_batch)

            # From the minibatch of new feature vectors, determine if they are in the estimated manifold.
            # If a feature vector is inside a hypersphere of some reference sample, then
            # the new sample lies at the estimated manifold.
            # The radii of the hyperspheres are determined from distances of neighborhood size k.
            samples_in_manifold = distance_batch[0 : end1 - begin1, :, None] <= radii
            batch_predictions[begin1:end1] = np.any(samples_in_manifold, axis=1).astype(np.int32)

            max_realism_score[begin1:end1] = np.max(
                radii[:, 0] / (distance_batch[0 : end1 - begin1, :] + self.eps), axis=1
            )
            nearest_indices[begin1:end1] = np.argmin(distance_batch[0 : end1 - begin1, :], axis=1)

        return {
            "fraction": float(np.mean(batch_predictions)),
            "batch_predictions": batch_predictions,
            "max_realisim_score": max_realism_score,
            "nearest_indices": nearest_indices,
        }