'Returns `array` split into subarrays corresponding to the
cluster structure.'

def cluster_list(self, array):

    if (array.ndim == 1):
        return [np.array(array[self.group_indices[k]]) for k in self.group_labels]
    else:
        return [np.array(array[self.group_indices[k], :]) for k in self.group_labels]
