def canonicalMachineName(machine=''):
    aliases = {'nstxu': ['nstx', 'nstxu', 'nstx-u'],
               'diiid': ['diiid', 'diii-d', 'd3d'],
               'cmod': ['cmod', 'c-mod']}
    for key, value in aliases.items():
        if machine.lower() in value:
            return key
    # invalid machine name
    raise FdpError('"{}" is not a valid machine name\n'.format(machine))