"""Tests for BeamFits object."""
import nose.tools as nt
import os
import numpy as np
import astropy
from astropy.io import fits
from pyuvdata import UVBeam
import pyuvdata.tests as uvtest
from pyuvdata.data import DATA_PATH
import pyuvdata.utils as uvutils

filenames = ['HERA_NicCST_150MHz.txt', 'HERA_NicCST_123MHz.txt']
cst_files = [os.path.join(DATA_PATH, f) for f in filenames]


def test_readCST_writereadFITS():
    beam_in = UVBeam()
    beam_out = UVBeam()
    beam_in.read_cst_beam(cst_files[0], beam_type='efield', frequency=150e6,
                          telescope_name='TEST', feed_name='bob',
                          feed_version='0.1', feed_pol=['x'],
                          model_name='E-field pattern - Rigging height 4.9m',
                          model_version='1.0')

    # add optional parameters for testing purposes
    beam_in.extra_keywords = {'KEY1': 'test_keyword'}
    beam_in.reference_input_impedance = 340.
    beam_in.reference_output_impedance = 50.
    beam_in.receiver_temperature_array = np.random.normal(50.0, 5, size=(beam_in.Nspws, beam_in.Nfreqs))
    beam_in.loss_array = np.random.normal(50.0, 5, size=(beam_in.Nspws, beam_in.Nfreqs))
    beam_in.mismatch_array = np.random.normal(0.0, 1.0, size=(beam_in.Nspws, beam_in.Nfreqs))
    beam_in.s_parameters = np.random.normal(0.0, 0.3, size=(4, beam_in.Nspws, beam_in.Nfreqs))

    write_file = os.path.join(DATA_PATH, 'test/outtest_beam.fits')

    beam_in.write_beamfits(write_file, clobber=True)
    beam_out.read_beamfits(write_file)

    nt.assert_equal(beam_in, beam_out)

    # redo for power beam
    del(beam_in)
    beam_in = UVBeam()
    # read in efield and convert to power to test cross-pols
    beam_in.read_cst_beam(cst_files[0], beam_type='efield', frequency=150e6,
                          telescope_name='TEST', feed_name='bob',
                          feed_version='0.1', feed_pol=['x'],
                          model_name='E-field pattern - Rigging height 4.9m',
                          model_version='1.0')
    beam_in.efield_to_power()

    # add optional parameters for testing purposes
    beam_in.extra_keywords = {'KEY1': 'test_keyword'}
    beam_in.reference_input_impedance = 340.
    beam_in.reference_output_impedance = 50.
    beam_in.receiver_temperature_array = np.random.normal(50.0, 5, size=(beam_in.Nspws, beam_in.Nfreqs))
    beam_in.loss_array = np.random.normal(50.0, 5, size=(beam_in.Nspws, beam_in.Nfreqs))
    beam_in.mismatch_array = np.random.normal(0.0, 1.0, size=(beam_in.Nspws, beam_in.Nfreqs))
    beam_in.s_parameters = np.random.normal(0.0, 0.3, size=(4, beam_in.Nspws, beam_in.Nfreqs))

    beam_in.write_beamfits(write_file, clobber=True)
    beam_out.read_beamfits(write_file)
    nt.assert_equal(beam_in, beam_out)

    # now replace 'power' with 'intensity' for btype
    F = fits.open(write_file)
    data = F[0].data
    primary_hdr = F[0].header
    primary_hdr['BTYPE'] = 'Intensity'
    hdunames = uvutils.fits_indexhdus(F)
    bandpass_hdu = F[hdunames['BANDPARM']]

    prihdu = fits.PrimaryHDU(data=data, header=primary_hdr)
    hdulist = fits.HDUList([prihdu, bandpass_hdu])

    if float(astropy.__version__[0:3]) < 1.3:
        hdulist.writeto(write_file, clobber=True)
    else:
        hdulist.writeto(write_file, overwrite=True)

    beam_out.read_beamfits(write_file)
    nt.assert_equal(beam_in, beam_out)

    # now remove coordsys but leave ctypes 1 & 2
    F = fits.open(write_file)
    data = F[0].data
    primary_hdr = F[0].header
    primary_hdr.pop('COORDSYS')
    hdunames = uvutils.fits_indexhdus(F)
    bandpass_hdu = F[hdunames['BANDPARM']]

    prihdu = fits.PrimaryHDU(data=data, header=primary_hdr)
    hdulist = fits.HDUList([prihdu, bandpass_hdu])

    if float(astropy.__version__[0:3]) < 1.3:
        hdulist.writeto(write_file, clobber=True)
    else:
        hdulist.writeto(write_file, overwrite=True)

    beam_out.read_beamfits(write_file)
    nt.assert_equal(beam_in, beam_out)

    # now change frequency units
    F = fits.open(write_file)
    data = F[0].data
    primary_hdr = F[0].header
    primary_hdr['CUNIT3'] = 'MHz'
    primary_hdr['CRVAL3'] = primary_hdr['CRVAL3'] / 1e6
    primary_hdr['CDELT3'] = primary_hdr['CRVAL3'] / 1e6
    hdunames = uvutils.fits_indexhdus(F)
    bandpass_hdu = F[hdunames['BANDPARM']]

    prihdu = fits.PrimaryHDU(data=data, header=primary_hdr)
    hdulist = fits.HDUList([prihdu, bandpass_hdu])

    if float(astropy.__version__[0:3]) < 1.3:
        hdulist.writeto(write_file, clobber=True)
    else:
        hdulist.writeto(write_file, overwrite=True)

    beam_out.read_beamfits(write_file)
    nt.assert_equal(beam_in, beam_out)


def test_writeread_healpix():
    beam_in = UVBeam()
    beam_out = UVBeam()
    # fill UVBeam object with dummy data for now for testing purposes
    beam_in.read_cst_beam(cst_files[0], beam_type='efield', frequency=150e6,
                          telescope_name='TEST', feed_name='bob',
                          feed_version='0.1', feed_pol=['x'],
                          model_name='E-field pattern - Rigging height 4.9m',
                          model_version='1.0')
    beam_in.az_za_to_healpix()

    write_file = os.path.join(DATA_PATH, 'test/outtest_beam_hpx.fits')

    beam_in.write_beamfits(write_file, clobber=True)
    beam_out.read_beamfits(write_file)

    nt.assert_equal(beam_in, beam_out)

    # redo for power beam
    del(beam_in)
    beam_in = UVBeam()
    # read in efield and convert to power to test cross-pols
    beam_in.read_cst_beam(cst_files[0], beam_type='efield', frequency=150e6,
                          telescope_name='TEST', feed_name='bob',
                          feed_version='0.1', feed_pol=['x'],
                          model_name='E-field pattern - Rigging height 4.9m',
                          model_version='1.0')
    beam_in.efield_to_power()

    # add optional parameters for testing purposes
    beam_in.extra_keywords = {'KEY1': 'test_keyword'}
    beam_in.reference_input_impedance = 340.
    beam_in.reference_output_impedance = 50.
    beam_in.receiver_temperature_array = np.random.normal(50.0, 5, size=(beam_in.Nspws, beam_in.Nfreqs))
    beam_in.loss_array = np.random.normal(50.0, 5, size=(beam_in.Nspws, beam_in.Nfreqs))
    beam_in.mismatch_array = np.random.normal(0.0, 1.0, size=(beam_in.Nspws, beam_in.Nfreqs))
    beam_in.s_parameters = np.random.normal(0.0, 0.3, size=(4, beam_in.Nspws, beam_in.Nfreqs))

    # check that data_array is complex
    nt.assert_true(np.iscomplexobj(np.real_if_close(beam_in.data_array, tol=10)))

    beam_in.az_za_to_healpix()
    # check that data_array is complex after interpolation
    nt.assert_true(np.iscomplexobj(np.real_if_close(beam_in.data_array, tol=10)))

    beam_in.write_beamfits(write_file, clobber=True)
    beam_out.read_beamfits(write_file)

    nt.assert_equal(beam_in, beam_out)

    # now remove coordsys but leave ctype 1
    F = fits.open(write_file)
    data = F[0].data
    primary_hdr = F[0].header
    primary_hdr.pop('COORDSYS')
    hdunames = uvutils.fits_indexhdus(F)
    hpx_hdu = F[hdunames['HPX_INDS']]
    bandpass_hdu = F[hdunames['BANDPARM']]

    prihdu = fits.PrimaryHDU(data=data, header=primary_hdr)
    hdulist = fits.HDUList([prihdu, hpx_hdu, bandpass_hdu])

    if float(astropy.__version__[0:3]) < 1.3:
        hdulist.writeto(write_file, clobber=True)
    else:
        hdulist.writeto(write_file, overwrite=True)

    beam_out.read_beamfits(write_file)
    nt.assert_equal(beam_in, beam_out)


def test_errors():
    beam_in = UVBeam()
    beam_out = UVBeam()
    beam_in.read_cst_beam(cst_files[0], beam_type='efield', frequency=150e6,
                          telescope_name='TEST', feed_name='bob',
                          feed_version='0.1', feed_pol=['x'],
                          model_name='E-field pattern - Rigging height 4.9m',
                          model_version='1.0')
    beam_in.beam_type = 'foo'

    write_file = os.path.join(DATA_PATH, 'test/outtest_beam.fits')
    nt.assert_raises(ValueError, beam_in.write_beamfits, write_file, clobber=True)
    nt.assert_raises(ValueError, beam_in.write_beamfits, write_file,
                     clobber=True, run_check=False)

    beam_in.beam_type = 'efield'
    beam_in.antenna_type = 'phased_array'
    write_file = os.path.join(DATA_PATH, 'test/outtest_beam.fits')
    nt.assert_raises(ValueError, beam_in.write_beamfits, write_file, clobber=True)

    # now change values for various items in primary hdu to test errors
    beam_in.antenna_type = 'simple'

    header_vals_to_change = [{'BTYPE': 'foo'}, {'COORDSYS': 'orthoslant_zenith'},
                             {'NAXIS': ''}, {'CUNIT1': 'foo'}, {'CUNIT2': 'foo'},
                             {'CUNIT3': 'foo'}]

    for i, hdr_dict in enumerate(header_vals_to_change):
        beam_in.write_beamfits(write_file, clobber=True)

        keyword = hdr_dict.keys()[0]
        new_val = hdr_dict[keyword]
        F = fits.open(write_file)
        data = F[0].data
        primary_hdr = F[0].header
        hdunames = uvutils.fits_indexhdus(F)
        basisvec_hdu = F[hdunames['BASISVEC']]
        bandpass_hdu = F[hdunames['BANDPARM']]

        if 'NAXIS' in keyword:
            ax_num = keyword.split('NAXIS')[1]
            if ax_num != '':
                ax_num = int(ax_num)
                ax_use = len(data.shape) - ax_num
                new_arrays = np.split(data, primary_hdr[keyword], axis=ax_use)
                data = new_arrays[0]
            else:
                data = np.squeeze(np.split(data, primary_hdr['NAXIS1'],
                                  axis=len(data.shape) - 1)[0])
        else:
            primary_hdr[keyword] = new_val

        prihdu = fits.PrimaryHDU(data=data, header=primary_hdr)
        hdulist = fits.HDUList([prihdu, basisvec_hdu, bandpass_hdu])

        if float(astropy.__version__[0:3]) < 1.3:
            hdulist.writeto(write_file, clobber=True)
        else:
            hdulist.writeto(write_file, overwrite=True)

        nt.assert_raises(ValueError, beam_out.read_beamfits, write_file)

    # now change values for various items in basisvec hdu to not match primary hdu
    header_vals_to_change = [{'COORDSYS': 'foo'}, {'CTYPE1': 'foo'},
                             {'CTYPE2': 'foo'},
                             {'CDELT1': np.diff(beam_in.axis1_array)[0] * 2},
                             {'CDELT2': np.diff(beam_in.axis2_array)[0] * 2},
                             {'NAXIS4': ''}, {'CUNIT1': 'foo'}, {'CUNIT2': 'foo'}]

    for i, hdr_dict in enumerate(header_vals_to_change):
        beam_in.write_beamfits(write_file, clobber=True)

        keyword = hdr_dict.keys()[0]
        new_val = hdr_dict[keyword]
        F = fits.open(write_file)
        data = F[0].data
        primary_hdr = F[0].header
        hdunames = uvutils.fits_indexhdus(F)
        basisvec_hdu = F[hdunames['BASISVEC']]
        basisvec_hdr = basisvec_hdu.header
        basisvec_data = basisvec_hdu.data
        bandpass_hdu = F[hdunames['BANDPARM']]

        if 'NAXIS' in keyword:
            ax_num = keyword.split('NAXIS')[1]
            if ax_num != '':
                ax_num = int(ax_num)
                ax_use = len(basisvec_data.shape) - ax_num
                new_arrays = np.split(basisvec_data, basisvec_hdr[keyword], axis=ax_use)
                basisvec_data = new_arrays[0]
            else:
                basisvec_data = np.split(basisvec_data, basisvec_hdr['NAXIS1'],
                                         axis=len(basisvec_data.shape) - 1)[0]
        else:
            basisvec_hdr[keyword] = new_val

        prihdu = fits.PrimaryHDU(data=data, header=primary_hdr)
        basisvec_hdu = fits.ImageHDU(data=basisvec_data, header=basisvec_hdr)
        hdulist = fits.HDUList([prihdu, basisvec_hdu, bandpass_hdu])

        if float(astropy.__version__[0:3]) < 1.3:
            hdulist.writeto(write_file, clobber=True)
        else:
            hdulist.writeto(write_file, overwrite=True)

        nt.assert_raises(ValueError, beam_out.read_beamfits, write_file)


def test_healpix_errors():
    beam_in = UVBeam()
    beam_out = UVBeam()
    write_file = os.path.join(DATA_PATH, 'test/outtest_beam_hpx.fits')

    # now change values for various items in primary hdu to test errors
    beam_in.read_cst_beam(cst_files[0], beam_type='efield', frequency=150e6,
                          telescope_name='TEST', feed_name='bob',
                          feed_version='0.1', feed_pol=['x'],
                          model_name='E-field pattern - Rigging height 4.9m',
                          model_version='1.0')
    beam_in.az_za_to_healpix()

    header_vals_to_change = [{'CTYPE1': 'foo'}, {'NAXIS1': ''}]

    for i, hdr_dict in enumerate(header_vals_to_change):
        beam_in.write_beamfits(write_file, clobber=True)

        keyword = hdr_dict.keys()[0]
        new_val = hdr_dict[keyword]
        F = fits.open(write_file)
        data = F[0].data
        primary_hdr = F[0].header
        hdunames = uvutils.fits_indexhdus(F)
        basisvec_hdu = F[hdunames['BASISVEC']]
        hpx_hdu = F[hdunames['HPX_INDS']]
        bandpass_hdu = F[hdunames['BANDPARM']]

        if 'NAXIS' in keyword:
            ax_num = keyword.split('NAXIS')[1]
            if ax_num != '':
                ax_num = int(ax_num)
                ax_use = len(data.shape) - ax_num
                new_arrays = np.split(data, primary_hdr[keyword], axis=ax_use)
                data = new_arrays[0]
            else:
                data = np.squeeze(np.split(data, primary_hdr['NAXIS1'],
                                  axis=len(data.shape) - 1)[0])
        else:
            primary_hdr[keyword] = new_val

        prihdu = fits.PrimaryHDU(data=data, header=primary_hdr)
        hdulist = fits.HDUList([prihdu, basisvec_hdu, hpx_hdu, bandpass_hdu])

        if float(astropy.__version__[0:3]) < 1.3:
            hdulist.writeto(write_file, clobber=True)
        else:
            hdulist.writeto(write_file, overwrite=True)

        nt.assert_raises(ValueError, beam_out.read_beamfits, write_file)

    # now change values for various items in basisvec hdu to not match primary hdu
    beam_in.read_cst_beam(cst_files[0], beam_type='efield', frequency=150e6,
                          telescope_name='TEST', feed_name='bob',
                          feed_version='0.1', feed_pol=['x'],
                          model_name='E-field pattern - Rigging height 4.9m',
                          model_version='1.0')
    beam_in.az_za_to_healpix()

    header_vals_to_change = [{'CTYPE1': 'foo'}, {'NAXIS1': ''}]

    for i, hdr_dict in enumerate(header_vals_to_change):
        beam_in.write_beamfits(write_file, clobber=True)

        keyword = hdr_dict.keys()[0]
        new_val = hdr_dict[keyword]
        F = fits.open(write_file)
        data = F[0].data
        primary_hdr = F[0].header
        hdunames = uvutils.fits_indexhdus(F)
        basisvec_hdu = F[hdunames['BASISVEC']]
        basisvec_hdr = basisvec_hdu.header
        basisvec_data = basisvec_hdu.data
        hpx_hdu = F[hdunames['HPX_INDS']]
        bandpass_hdu = F[hdunames['BANDPARM']]

        if 'NAXIS' in keyword:
            ax_num = keyword.split('NAXIS')[1]
            if ax_num != '':
                ax_num = int(ax_num)
                ax_use = len(basisvec_data.shape) - ax_num
                new_arrays = np.split(basisvec_data, basisvec_hdr[keyword], axis=ax_use)
                basisvec_data = new_arrays[0]
            else:
                basisvec_data = np.split(basisvec_data, basisvec_hdr['NAXIS1'],
                                         axis=len(basisvec_data.shape) - 1)[0]
        else:
            basisvec_hdr[keyword] = new_val

        prihdu = fits.PrimaryHDU(data=data, header=primary_hdr)
        basisvec_hdu = fits.ImageHDU(data=basisvec_data, header=basisvec_hdr)
        hdulist = fits.HDUList([prihdu, basisvec_hdu, hpx_hdu, bandpass_hdu])

        if float(astropy.__version__[0:3]) < 1.3:
            hdulist.writeto(write_file, clobber=True)
        else:
            hdulist.writeto(write_file, overwrite=True)

        nt.assert_raises(ValueError, beam_out.read_beamfits, write_file)


def test_casa_beam():
    # test reading in CASA power beam. Some header items are missing...
    beam_in = UVBeam()
    beam_out = UVBeam()
    casa_file = os.path.join(DATA_PATH, 'HERABEAM.FITS')
    write_file = os.path.join(DATA_PATH, 'test/outtest_beam.fits')
    beam_in.read_beamfits(casa_file, run_check=False)

    # fill in missing parameters
    beam_in.data_normalization = 'peak'
    beam_in.feed_name = 'casa_ideal'
    beam_in.feed_version = 'v0'
    beam_in.model_name = 'casa_airy'
    beam_in.model_version = 'v0'

    # this file is actually in an orthoslant projection RA/DEC at zenith at a particular time.
    # For now pretend it's in a zenith orthoslant projection
    beam_in.pixel_coordinate_system = 'orthoslant_zenith'

    expected_extra_keywords = ['OBSERVER', 'OBSDEC', 'DATAMIN', 'OBJECT',
                               'INSTRUME', 'DATAMAX', 'OBSRA', 'ORIGIN',
                               'DATE-MAP', 'DATE', 'EQUINOX', 'DATE-OBS',
                               'COMMENT']
    nt.assert_equal(expected_extra_keywords.sort(),
                    beam_in.extra_keywords.keys().sort())

    beam_in.write_beamfits(write_file, clobber=True)
    beam_out.read_beamfits(write_file)

    nt.assert_equal(beam_in, beam_out)


def test_extra_keywords():
    beam_in = UVBeam()
    beam_out = UVBeam()
    casa_file = os.path.join(DATA_PATH, 'HERABEAM.FITS')
    testfile = os.path.join(DATA_PATH, 'test/outtest_beam.fits')
    beam_in.read_beamfits(casa_file, run_check=False)

    # fill in missing parameters
    beam_in.data_normalization = 'peak'
    beam_in.feed_name = 'casa_ideal'
    beam_in.feed_version = 'v0'
    beam_in.model_name = 'casa_airy'
    beam_in.model_version = 'v0'

    # this file is actually in an orthoslant projection RA/DEC at zenith at a particular time.
    # For now pretend it's in a zenith orthoslant projection
    beam_in.pixel_coordinate_system = 'orthoslant_zenith'

    # check for warnings & errors with extra_keywords that are dicts, lists or arrays
    beam_in.extra_keywords['testdict'] = {'testkey': 23}
    uvtest.checkWarnings(beam_in.check, message=['testdict in extra_keywords is a '
                                                 'list, array or dict'])
    nt.assert_raises(TypeError, beam_in.write_beamfits, testfile, run_check=False)
    beam_in.extra_keywords.pop('testdict')

    beam_in.extra_keywords['testlist'] = [12, 14, 90]
    uvtest.checkWarnings(beam_in.check, message=['testlist in extra_keywords is a '
                                                 'list, array or dict'])
    nt.assert_raises(TypeError, beam_in.write_beamfits, testfile, run_check=False)
    beam_in.extra_keywords.pop('testlist')

    beam_in.extra_keywords['testarr'] = np.array([12, 14, 90])
    uvtest.checkWarnings(beam_in.check, message=['testarr in extra_keywords is a '
                                                 'list, array or dict'])
    nt.assert_raises(TypeError, beam_in.write_beamfits, testfile, run_check=False)
    beam_in.extra_keywords.pop('testarr')

    # check for warnings with extra_keywords keys that are too long
    beam_in.extra_keywords['test_long_key'] = True
    uvtest.checkWarnings(beam_in.check, message=['key test_long_key in extra_keywords '
                                                 'is longer than 8 characters'])
    uvtest.checkWarnings(beam_in.write_beamfits, [testfile], {'run_check': False,
                                                              'clobber': True},
                         message=['key test_long_key in extra_keywords is longer than 8 characters'])
    beam_in.extra_keywords.pop('test_long_key')

    # check handling of boolean keywords
    beam_in.extra_keywords['bool'] = True
    beam_in.extra_keywords['bool2'] = False
    beam_in.write_beamfits(testfile, clobber=True)
    beam_out.read_beamfits(testfile, run_check=False)

    nt.assert_equal(beam_in, beam_out)
    beam_in.extra_keywords.pop('bool')
    beam_in.extra_keywords.pop('bool2')

    # check handling of int-like keywords
    beam_in.extra_keywords['int1'] = np.int(5)
    beam_in.extra_keywords['int2'] = 7
    beam_in.write_beamfits(testfile, clobber=True)
    beam_out.read_beamfits(testfile, run_check=False)

    nt.assert_equal(beam_in, beam_out)
    beam_in.extra_keywords.pop('int1')
    beam_in.extra_keywords.pop('int2')

    # check handling of float-like keywords
    beam_in.extra_keywords['float1'] = np.int64(5.3)
    beam_in.extra_keywords['float2'] = 6.9
    beam_in.write_beamfits(testfile, clobber=True)
    beam_out.read_beamfits(testfile, run_check=False)

    nt.assert_equal(beam_in, beam_out)
    beam_in.extra_keywords.pop('float1')
    beam_in.extra_keywords.pop('float2')

    # check handling of complex-like keywords
    beam_in.extra_keywords['complex1'] = np.complex64(5.3 + 1.2j)
    beam_in.extra_keywords['complex2'] = 6.9 + 4.6j
    beam_in.write_beamfits(testfile, clobber=True)
    beam_out.read_beamfits(testfile, run_check=False)

    nt.assert_equal(beam_in, beam_out)


def test_multi_files():
    """
    Reading multiple files at once.
    """
    beam_full = UVBeam()
    beam_full.read_cst_beam(cst_files, beam_type='efield', frequency=[150e6, 123e6],
                            telescope_name='TEST', feed_name='bob',
                            feed_version='0.1', feed_pol=['x'],
                            model_name='E-field pattern - Rigging height 4.9m',
                            model_version='1.0')

    # add optional parameters for testing purposes
    beam_full.extra_keywords = {'KEY1': 'test_keyword'}
    beam_full.reference_input_impedance = 340.
    beam_full.reference_output_impedance = 50.
    beam_full.receiver_temperature_array = np.random.normal(50.0, 5, size=(beam_full.Nspws, beam_full.Nfreqs))
    beam_full.loss_array = np.random.normal(50.0, 5, size=(beam_full.Nspws, beam_full.Nfreqs))
    beam_full.mismatch_array = np.random.normal(0.0, 1.0, size=(beam_full.Nspws, beam_full.Nfreqs))
    beam_full.s_parameters = np.random.normal(0.0, 0.3, size=(4, beam_full.Nspws, beam_full.Nfreqs))

    testfile1 = os.path.join(DATA_PATH, 'test/outtest_beam1.fits')
    testfile2 = os.path.join(DATA_PATH, 'test/outtest_beam2.fits')

    beam1 = beam_full.select(freq_chans=0, inplace=False)
    beam2 = beam_full.select(freq_chans=1, inplace=False)
    beam1.write_beamfits(testfile1, clobber=True)
    beam2.write_beamfits(testfile2, clobber=True)
    beam1.read_beamfits([testfile1, testfile2])
    # Check history is correct, before replacing and doing a full object check
    nt.assert_true(uvutils.check_histories(beam_full.history + '  Downselected '
                                           'to specific frequencies using pyuvdata. '
                                           'Combined data along frequency axis using'
                                           ' pyuvdata.', beam1.history))

    beam1.history = beam_full.history
    nt.assert_equal(beam1, beam_full)