def bin_edges_to_centres(edges):
    """
    Translates edges of histogram bins to bin centres.
    """
    if edges.ndim == 1:
        steps = (edges[1:] - edges[:-1]) / 2
        return edges[:-1] + steps
    else:
        steps = (edges[1:, 1:] - edges[:-1, :-1]) / 2
        centres = edges[:-1, :-1] + steps
        return centres