def test_poltoind():
miriad_uv = UVData()
miriad_file = os.path.join(DATA_PATH, 'zen.2456865.60537.xy.uvcRREAA')
uvtest.checkWarnings(miriad_uv.read, [miriad_file], known_warning='miriad')
pol_arr = miriad_uv.polarization_array
miriad = miriad_uv._convert_to_filetype('miriad')
miriad.polarization_array = None
nt.assert_raises(ValueError, miriad._pol_to_ind, pol_arr[0])
miriad.polarization_array = [pol_arr[0], pol_arr[0]]
nt.assert_raises(ValueError, miriad._pol_to_ind, pol_arr[0])
