def _get_miller_array_from_label(mtz_object, column_label):
    """Assuming only a single crystal/dataset, return the miller array for the given column label"""
    # Get the miller arrays for the columns we're interested in as dicts
    miller_dict = mtz_object.as_miller_arrays_dict()
    # Keys are 3-tuples where last item is array label
    try:
        col_key = [k for k in miller_dict.keys() if k[2] == column_label][0]
    except IndexError:
        raise RuntimeError("Cannot find column label: {0}".format(column_label))
    assert col_key
    return miller_dict[col_key]