def _difference(data, names):
    """Data condition x subject"""
    data_differences = []
    diffnames = []
    diffnames_2lines = []
    for i, (name1, data1) in enumerate(zip(names, data)):
        for name2, data2 in zip(names[i + 1:], data[i + 1:]):
            data_differences.append(data1 - data2)
            diffnames.append('-'.join([name1, name2]))
            diffnames_2lines.append('-\n'.join([name1, name2]))
    return data_differences, diffnames, diffnames_2lines
