How to use the biosppy.metrics function in biosppy

target subject labels (`train_labels`).

        """

        # target class labels
        if targets is None:
            targets = list(six.itervalues(self._subject2label))
        elif isinstance(targets, six.string_types):
            targets = [targets]

        dists = []
        train_labels = []

        for label in targets:
            # compute distances
            D = metrics.cdist(data, self.io_load(label),
                              metric=self.metric, **self.metric_args)

            dists.append(D)
            train_labels.append(np.tile(label, D.shape))

        dists = np.concatenate(dists, axis=1)
        train_labels = np.concatenate(train_labels, axis=1)

        # sort
        dists, train_labels = self._sort(dists, train_labels)

        return {'dists': dists, 'train_labels': train_labels}