Beispiel #1
0
def test_fits():
    try:
        import fitsio
    except ImportError:
        print('Skipping FITS tests, since fitsio is not installed')
        return

    get_from_wiki('Aardvark.fit')
    file_name = os.path.join('data','Aardvark.fit')
    config = treecorr.read_config('Aardvark.yaml')
    config['verbose'] = 1

    # Just test a few random particular values
    cat1 = treecorr.Catalog(file_name, config)
    np.testing.assert_equal(len(cat1.ra), 390935)
    np.testing.assert_equal(cat1.nobj, 390935)
    np.testing.assert_almost_equal(cat1.ra[0], 56.4195 * (pi/180.))
    np.testing.assert_almost_equal(cat1.ra[390934], 78.4782 * (pi/180.))
    np.testing.assert_almost_equal(cat1.dec[290333], 83.1579 * (pi/180.))
    np.testing.assert_almost_equal(cat1.g1[46392], 0.0005066675)
    np.testing.assert_almost_equal(cat1.g2[46392], -0.0001006742)
    np.testing.assert_almost_equal(cat1.k[46392], -0.0008628797)

    # The catalog doesn't have x, y, or w, but test that functionality as well.
    del config['ra_col']
    del config['dec_col']
    config['x_col'] = 'RA'
    config['y_col'] = 'DEC'
    config['w_col'] = 'MU'
    config['flag_col'] = 'INDEX'
    config['ignore_flag'] = 64
    cat2 = treecorr.Catalog(file_name, config)
    np.testing.assert_almost_equal(cat2.x[390934], 78.4782, decimal=4)
    np.testing.assert_almost_equal(cat2.y[290333], 83.1579, decimal=4)
    np.testing.assert_almost_equal(cat2.w[46392], 0.)        # index = 1200379
    np.testing.assert_almost_equal(cat2.w[46393], 0.9995946) # index = 1200386

    # Test using a limited set of rows
    config['first_row'] = 101
    config['last_row'] = 50000
    cat3 = treecorr.Catalog(file_name, config)
    np.testing.assert_equal(len(cat3.x), 49900)
    np.testing.assert_equal(cat3.ntot, 49900)
    np.testing.assert_equal(cat3.nobj, sum(cat3.w != 0))
    np.testing.assert_equal(cat3.sumw, sum(cat3.w))
    np.testing.assert_equal(cat3.sumw, sum(cat2.w[100:50000]))
    np.testing.assert_almost_equal(cat3.g1[46292], 0.0005066675)
    np.testing.assert_almost_equal(cat3.g2[46292], -0.0001006742)
    np.testing.assert_almost_equal(cat3.k[46292], -0.0008628797)

    cat4 = treecorr.read_catalogs(config, key='file_name', is_rand=True)[0]
    np.testing.assert_equal(len(cat4.x), 49900)
    np.testing.assert_equal(cat4.ntot, 49900)
    np.testing.assert_equal(cat4.nobj, sum(cat4.w != 0))
    np.testing.assert_equal(cat4.sumw, sum(cat4.w))
    np.testing.assert_equal(cat4.sumw, sum(cat2.w[100:50000]))
    assert cat4.g1 is None
    assert cat4.g2 is None
    assert cat4.k is None
Beispiel #2
0
def test_direct_perp():
    # This is the same as the above test, but using the perpendicular distance metric

    get_from_wiki('nn_perp_data.dat')
    get_from_wiki('nn_perp_rand.dat')

    ngal = 100
    s = 10.
    numpy.random.seed(8675309)
    x1 = numpy.random.normal(312, s, (ngal,) )
    y1 = numpy.random.normal(728, s, (ngal,) )
    z1 = numpy.random.normal(-932, s, (ngal,) )
    r1 = numpy.sqrt( x1*x1 + y1*y1 + z1*z1 )
    dec1 = numpy.arcsin(z1/r1)
    ra1 = numpy.arctan2(y1,x1)
    cat1 = treecorr.Catalog(ra=ra1, dec=dec1, r=r1, ra_units='rad', dec_units='rad')

    x2 = numpy.random.normal(312, s, (ngal,) )
    y2 = numpy.random.normal(728, s, (ngal,) )
    z2 = numpy.random.normal(-932, s, (ngal,) )
    r2 = numpy.sqrt( x2*x2 + y2*y2 + z2*z2 )
    dec2 = numpy.arcsin(z2/r2)
    ra2 = numpy.arctan2(y2,x2)
    cat2 = treecorr.Catalog(ra=ra2, dec=dec2, r=r2, ra_units='rad', dec_units='rad')

    min_sep = 1.
    max_sep = 50.
    nbins = 50
    dd = treecorr.NNCorrelation(min_sep=min_sep, max_sep=max_sep, nbins=nbins, bin_slop=0.)
    dd.process(cat1, cat2, metric='Rperp')
    print('dd.npairs = ',dd.npairs)

    log_min_sep = numpy.log(min_sep)
    log_max_sep = numpy.log(max_sep)
    true_npairs = numpy.zeros(nbins)
    bin_size = (log_max_sep - log_min_sep) / nbins
    for i in range(ngal):
        for j in range(ngal):
            rsq = (x1[i]-x2[j])**2 + (y1[i]-y2[j])**2 + (z1[i]-z2[j])**2
            rsq -= (r1[i] - r2[j])**2
            logr = 0.5 * numpy.log(rsq)
            k = int(numpy.floor( (logr-log_min_sep) / bin_size ))
            if k < 0: continue
            if k >= nbins: continue
            true_npairs[k] += 1

    print('true_npairs = ',true_npairs)
    print('diff = ',dd.npairs - true_npairs)
    numpy.testing.assert_array_equal(dd.npairs, true_npairs)

    # Can also specify coords directly as x,y,z
    cat1 = treecorr.Catalog(x=x1, y=y1, z=z1)
    cat2 = treecorr.Catalog(x=x2, y=y2, z=z2)
    dd.process(cat1, cat2, metric='Rperp')
    numpy.testing.assert_array_equal(dd.npairs, true_npairs)
Beispiel #3
0
def test_direct_perp():
    # This is the same as the above test, but using the perpendicular distance metric

    get_from_wiki('nn_perp_data.dat')
    get_from_wiki('nn_perp_rand.dat')

    ngal = 100
    s = 10.
    numpy.random.seed(8675309)
    x1 = numpy.random.normal(312, s, (ngal,) )
    y1 = numpy.random.normal(728, s, (ngal,) )
    z1 = numpy.random.normal(-932, s, (ngal,) )
    r1 = numpy.sqrt( x1*x1 + y1*y1 + z1*z1 )
    dec1 = numpy.arcsin(z1/r1)
    ra1 = numpy.arctan2(y1,x1)
    cat1 = treecorr.Catalog(ra=ra1, dec=dec1, r=r1, ra_units='rad', dec_units='rad')

    x2 = numpy.random.normal(312, s, (ngal,) )
    y2 = numpy.random.normal(728, s, (ngal,) )
    z2 = numpy.random.normal(-932, s, (ngal,) )
    r2 = numpy.sqrt( x2*x2 + y2*y2 + z2*z2 )
    dec2 = numpy.arcsin(z2/r2)
    ra2 = numpy.arctan2(y2,x2)
    cat2 = treecorr.Catalog(ra=ra2, dec=dec2, r=r2, ra_units='rad', dec_units='rad')

    min_sep = 1.
    max_sep = 50.
    nbins = 50
    dd = treecorr.NNCorrelation(min_sep=min_sep, max_sep=max_sep, nbins=nbins, bin_slop=0.)
    dd.process(cat1, cat2, metric='Rperp')
    print('dd.npairs = ',dd.npairs)

    log_min_sep = numpy.log(min_sep)
    log_max_sep = numpy.log(max_sep)
    true_npairs = numpy.zeros(nbins)
    bin_size = (log_max_sep - log_min_sep) / nbins
    for i in range(ngal):
        for j in range(ngal):
            rsq = (x1[i]-x2[j])**2 + (y1[i]-y2[j])**2 + (z1[i]-z2[j])**2
            rsq -= (r1[i] - r2[j])**2
            logr = 0.5 * numpy.log(rsq)
            k = int(numpy.floor( (logr-log_min_sep) / bin_size ))
            if k < 0: continue
            if k >= nbins: continue
            true_npairs[k] += 1

    print('true_npairs = ',true_npairs)
    print('diff = ',dd.npairs - true_npairs)
    numpy.testing.assert_array_equal(dd.npairs, true_npairs)

    # Can also specify coords directly as x,y,z
    cat1 = treecorr.Catalog(x=x1, y=y1, z=z1)
    cat2 = treecorr.Catalog(x=x2, y=y2, z=z2)
    dd.process(cat1, cat2, metric='Rperp')
    numpy.testing.assert_array_equal(dd.npairs, true_npairs)
Beispiel #4
0
def test_fits():
    get_from_wiki('Aardvark.fit')
    file_name = os.path.join('data','Aardvark.fit')
    config = treecorr.read_config('Aardvark.yaml')
    config['verbose'] = 1

    # Just test a few random particular values
    cat1 = treecorr.Catalog(file_name, config)
    numpy.testing.assert_equal(len(cat1.ra), 390935)
    numpy.testing.assert_equal(cat1.nobj, 390935)
    numpy.testing.assert_almost_equal(cat1.ra[0], 56.4195 * (pi/180.))
    numpy.testing.assert_almost_equal(cat1.ra[390934], 78.4782 * (pi/180.))
    numpy.testing.assert_almost_equal(cat1.dec[290333], 83.1579 * (pi/180.))
    numpy.testing.assert_almost_equal(cat1.g1[46392], 0.0005066675)
    numpy.testing.assert_almost_equal(cat1.g2[46392], -0.0001006742)
    numpy.testing.assert_almost_equal(cat1.k[46392], -0.0008628797)

    # The catalog doesn't have x, y, or w, but test that functionality as well.
    del config['ra_col']
    del config['dec_col']
    config['x_col'] = 'RA'
    config['y_col'] = 'DEC'
    config['w_col'] = 'MU'
    config['flag_col'] = 'INDEX'
    config['ignore_flag'] = 64
    cat2 = treecorr.Catalog(file_name, config)
    numpy.testing.assert_almost_equal(cat2.x[390934], 78.4782, decimal=4)
    numpy.testing.assert_almost_equal(cat2.y[290333], 83.1579, decimal=4)
    numpy.testing.assert_almost_equal(cat2.w[46392], 0.)        # index = 1200379
    numpy.testing.assert_almost_equal(cat2.w[46393], 0.9995946) # index = 1200386

    # Test using a limited set of rows
    config['first_row'] = 101
    config['last_row'] = 50000
    cat3 = treecorr.Catalog(file_name, config)
    numpy.testing.assert_equal(len(cat3.x), 49900)
    numpy.testing.assert_equal(cat3.ntot, 49900)
    numpy.testing.assert_equal(cat3.nobj, sum(cat3.w != 0))
    numpy.testing.assert_equal(cat3.sumw, sum(cat3.w))
    numpy.testing.assert_equal(cat3.sumw, sum(cat2.w[100:50000]))
    numpy.testing.assert_almost_equal(cat3.g1[46292], 0.0005066675)
    numpy.testing.assert_almost_equal(cat3.g2[46292], -0.0001006742)
    numpy.testing.assert_almost_equal(cat3.k[46292], -0.0008628797)
Beispiel #5
0
def test_fits():
    get_from_wiki('Aardvark.fit')
    file_name = os.path.join('data', 'Aardvark.fit')
    config = treecorr.read_config('Aardvark.params')

    # Just test a few random particular values
    cat1 = treecorr.Catalog(file_name, config)
    numpy.testing.assert_equal(len(cat1.ra), 390935)
    numpy.testing.assert_equal(cat1.nobj, 390935)
    numpy.testing.assert_almost_equal(cat1.ra[0], 56.4195 * (pi / 180.))
    numpy.testing.assert_almost_equal(cat1.ra[390934], 78.4782 * (pi / 180.))
    numpy.testing.assert_almost_equal(cat1.dec[290333], 83.1579 * (pi / 180.))
    numpy.testing.assert_almost_equal(cat1.g1[46392], 0.0005066675)
    numpy.testing.assert_almost_equal(cat1.g2[46392], -0.0001006742)
    numpy.testing.assert_almost_equal(cat1.k[46392], -0.0008628797)

    # The catalog doesn't have x, y, or w, but test that functionality as well.
    del config['ra_col']
    del config['dec_col']
    config['x_col'] = 'RA'
    config['y_col'] = 'DEC'
    config['w_col'] = 'MU'
    config['flag_col'] = 'INDEX'
    config['ignore_flag'] = 64
    cat2 = treecorr.Catalog(file_name, config)
    numpy.testing.assert_almost_equal(cat2.x[390934], 78.4782, decimal=4)
    numpy.testing.assert_almost_equal(cat2.y[290333], 83.1579, decimal=4)
    numpy.testing.assert_almost_equal(cat2.w[46392], 0.)  # index = 1200379
    numpy.testing.assert_almost_equal(cat2.w[46393],
                                      0.9995946)  # index = 1200386

    # Test using a limited set of rows
    config['first_row'] = 101
    config['last_row'] = 50000
    cat3 = treecorr.Catalog(file_name, config)
    numpy.testing.assert_equal(len(cat3.x), 49900)
    numpy.testing.assert_equal(cat3.ntot, 49900)
    numpy.testing.assert_equal(cat3.nobj, sum(cat3.w != 0))
    numpy.testing.assert_equal(cat3.sumw, sum(cat3.w))
    numpy.testing.assert_equal(cat3.sumw, sum(cat2.w[100:50000]))
    numpy.testing.assert_almost_equal(cat3.g1[46292], 0.0005066675)
    numpy.testing.assert_almost_equal(cat3.g2[46292], -0.0001006742)
    numpy.testing.assert_almost_equal(cat3.k[46292], -0.0008628797)
Beispiel #6
0
def setup():
    from test_helper import get_from_wiki

    file_name = os.path.join('data', 'Aardvark.fit')
    patch_file = os.path.join('data', 'mpi_patches.fits')

    # Make sure we have Aardvark.fit
    get_from_wiki('Aardvark.fit')

    # And all the tests will use these patches.  Make them once and save them.
    # For a real-life example, this might be made once and saved.
    # Or it might be made from a smaller version of the catalog:
    # either with the every_nth option, or maybe on a redmagic catalog or similar,
    # which would be smaller than the full source catalog, etc.
    if not os.path.exists(patch_file):
        part_cat = treecorr.Catalog(file_name,
                                    ra_col='RA',
                                    dec_col='DEC',
                                    ra_units='deg',
                                    dec_units='deg',
                                    npatch=8)
        part_cat.write_patch_centers(patch_file)
        del part_cat
Beispiel #7
0
def download():
    # The download can be a bit slow, and the files need to be merged to get something
    # that includes both ra/dec and e1,e2.  So we did this block once and uploaded
    # the results to the wiki.  Normal test running can just get the result from the wiki.

    # Download the public DES SV files (if not already downloaded)
    host = 'http://desdr-server.ncsa.illinois.edu/despublic/sva1_files/'
    lens_file = 'redmagic_sva1_public_v6.3_faint.fits.gz'
    get_from_wiki(lens_file, host=host)
    lens_file = os.path.join('data', lens_file)

    ngmix_file = 'sva1_gold_r1.0_ngmix.fits.gz'
    get_from_wiki(ngmix_file, host=host)
    ngmix_file = os.path.join('data', ngmix_file)

    info_file = 'sva1_gold_r1.0_wlinfo.fits.gz'
    get_from_wiki(info_file, host=host)
    info_file = os.path.join('data', info_file)

    source_file = os.path.join('data', 'sva1_gold_r1.0_merged.fits')
    if not os.path.exists(source_file):
        print('Reading ngmix_data')
        ngmix_data = fitsio.read(ngmix_file)
        print('Reading info_data')
        info_data = fitsio.read(info_file)

        col_names = ['RA', 'DEC']
        cols = [info_data[n] for n in col_names]  # These come from wlinfo
        col_names += ['E_1', 'E_2', 'W']
        cols += [ngmix_data[n] for n in col_names[2:]]  # These are in ngmix

        # combine the two sensitivity estimates
        col_names += ['SENS']
        cols += [(ngmix_data['SENS_1'] + ngmix_data['SENS_2']) / 2.]

        # Save time by cutting to only flag != 0 objects here.
        use = info_data['NGMIX_FLAG'] == 0
        print('total number of galaxies = ', len(use))
        print('number to use = ', np.sum(use))
        cols = [col[use] for col in cols]
        print('writing merged file: ', source_file)
        treecorr.util.gen_write(source_file, col_names, cols, file_type='FITS')

    return source_file, lens_file
Beispiel #8
0
def test_fits():
    try:
        import fitsio
    except ImportError:
        print('Skipping FITS tests, since fitsio is not installed')
        return

    get_from_wiki('Aardvark.fit')
    file_name = os.path.join('data','Aardvark.fit')
    config = treecorr.read_config('Aardvark.yaml')
    config['verbose'] = 1
    config['kk_file_name'] = 'kk.fits'
    config['gg_file_name'] = 'gg.fits'

    # Just test a few random particular values
    cat1 = treecorr.Catalog(file_name, config)
    np.testing.assert_equal(len(cat1.ra), 390935)
    np.testing.assert_equal(cat1.nobj, 390935)
    np.testing.assert_almost_equal(cat1.ra[0], 56.4195 * (pi/180.))
    np.testing.assert_almost_equal(cat1.ra[390934], 78.4782 * (pi/180.))
    np.testing.assert_almost_equal(cat1.dec[290333], 83.1579 * (pi/180.))
    np.testing.assert_almost_equal(cat1.g1[46392], 0.0005066675)
    np.testing.assert_almost_equal(cat1.g2[46392], -0.0001006742)
    np.testing.assert_almost_equal(cat1.k[46392], -0.0008628797)

    assert_raises(ValueError, treecorr.Catalog, file_name, config, ra_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, dec_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, r_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, w_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, wpos_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, flag_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, g1_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, g2_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, k_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, ra_col='0')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, dec_col='0')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, x_col='x')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, y_col='y')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, z_col='z')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, ra_col='0', dec_col='0')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, g1_col='0')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, g2_col='0')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, k_col='0')
    assert_raises(TypeError, treecorr.Catalog, file_name, config, x_units='arcmin')
    assert_raises(TypeError, treecorr.Catalog, file_name, config, y_units='arcmin')
    del config['ra_units']
    assert_raises(TypeError, treecorr.Catalog, file_name, config)
    del config['dec_units']
    assert_raises(TypeError, treecorr.Catalog, file_name, config, ra_units='deg')

    # The catalog doesn't have x, y, or w, but test that functionality as well.
    del config['ra_col']
    del config['dec_col']
    config['x_col'] = 'RA'
    config['y_col'] = 'DEC'
    config['w_col'] = 'MU'
    config['flag_col'] = 'INDEX'
    config['ignore_flag'] = 64
    cat2 = treecorr.Catalog(file_name, config)
    np.testing.assert_almost_equal(cat2.x[390934], 78.4782, decimal=4)
    np.testing.assert_almost_equal(cat2.y[290333], 83.1579, decimal=4)
    np.testing.assert_almost_equal(cat2.w[46392], 0.)        # index = 1200379
    np.testing.assert_almost_equal(cat2.w[46393], 0.9995946) # index = 1200386

    assert_raises(ValueError, treecorr.Catalog, file_name, config, x_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, y_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, z_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, ra_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, dec_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, r_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, w_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, wpos_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, flag_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, g1_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, g2_col='invalid')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, k_col='invalid')

    # Test using a limited set of rows
    config['first_row'] = 101
    config['last_row'] = 50000
    cat3 = treecorr.Catalog(file_name, config)
    np.testing.assert_equal(len(cat3.x), 49900)
    np.testing.assert_equal(cat3.ntot, 49900)
    np.testing.assert_equal(cat3.nobj, sum(cat3.w != 0))
    np.testing.assert_equal(cat3.sumw, sum(cat3.w))
    np.testing.assert_equal(cat3.sumw, sum(cat2.w[100:50000]))
    np.testing.assert_almost_equal(cat3.g1[46292], 0.0005066675)
    np.testing.assert_almost_equal(cat3.g2[46292], -0.0001006742)
    np.testing.assert_almost_equal(cat3.k[46292], -0.0008628797)

    cat4 = treecorr.read_catalogs(config, key='file_name', is_rand=True)[0]
    np.testing.assert_equal(len(cat4.x), 49900)
    np.testing.assert_equal(cat4.ntot, 49900)
    np.testing.assert_equal(cat4.nobj, sum(cat4.w != 0))
    np.testing.assert_equal(cat4.sumw, sum(cat4.w))
    np.testing.assert_equal(cat4.sumw, sum(cat2.w[100:50000]))
    assert cat4.g1 is None
    assert cat4.g2 is None
    assert cat4.k is None

    do_pickle(cat1)
    do_pickle(cat2)
    do_pickle(cat3)
    do_pickle(cat4)

    assert_raises(ValueError, treecorr.Catalog, file_name, config, first_row=-10)
    assert_raises(ValueError, treecorr.Catalog, file_name, config, first_row=0)
    assert_raises(ValueError, treecorr.Catalog, file_name, config, first_row=60000)
    assert_raises(ValueError, treecorr.Catalog, file_name, config, first_row=50001)

    assert_raises(TypeError, treecorr.read_catalogs, config)
    assert_raises(TypeError, treecorr.read_catalogs, config, key='file_name', list_key='file_name')

    # If gg output not given, it is still invalid to only have one or the other of g1,g2.
    del config['gg_file_name']
    assert_raises(ValueError, treecorr.Catalog, file_name, config, g1_col='0')
    assert_raises(ValueError, treecorr.Catalog, file_name, config, g2_col='0')
Beispiel #9
0
def test_dessv():
    try:
        import fitsio
    except ImportError:
        print('Skipping dessv test, since fitsio is not installed')
        return

    #treecorr.set_omp_threads(1);
    get_from_wiki('des_sv.fits')
    file_name = os.path.join('data', 'des_sv.fits')
    cat = treecorr.Catalog(file_name,
                           ra_col='ra',
                           dec_col='dec',
                           ra_units='deg',
                           dec_units='deg')

    # Use an odd number to make sure we force some of the shuffle bits in InitializeCenters
    # to happen.
    npatch = 43
    field = cat.getNField()
    t0 = time.time()
    patches = field.run_kmeans(npatch)
    t1 = time.time()
    print('patches = ', np.unique(patches))
    assert len(patches) == cat.ntot
    assert min(patches) == 0
    assert max(patches) == npatch - 1

    # KMeans minimizes the total inertia.
    # Check this value and the rms size, which should also be quite small.
    xyz = np.array([cat.x, cat.y, cat.z]).T
    cen = np.array([xyz[patches == i].mean(axis=0) for i in range(npatch)])
    inertia = np.array(
        [np.sum((xyz[patches == i] - cen[i])**2) for i in range(npatch)])
    sizes = np.array(
        [np.mean((xyz[patches == i] - cen[i])**2) for i in range(npatch)])**0.5
    sizes *= 180. / np.pi * 60.  # convert to arcmin
    counts = np.array([np.sum(patches == i) for i in range(npatch)])

    print('With standard algorithm:')
    print('time = ', t1 - t0)
    print('total inertia = ', np.sum(inertia))
    print('mean inertia = ', np.mean(inertia))
    print('rms inertia = ', np.std(inertia))
    print('mean size = ', np.mean(sizes))
    print('rms size = ', np.std(sizes))
    assert np.sum(
        inertia
    ) < 200.  # This is specific to this particular field and npatch.
    assert np.std(inertia) < 0.3 * np.mean(
        inertia)  # rms is usually < 0.2 * mean
    assert np.std(sizes) < 0.1 * np.mean(
        sizes)  # sizes have even less spread usually.

    # Should all have similar number of points.  Nothing is required here though.
    print('mean counts = ', np.mean(counts))
    print('min counts = ', np.min(counts))
    print('max counts = ', np.max(counts))

    # Check the alternate algorithm.  rms inertia should be lower.
    t0 = time.time()
    patches = field.run_kmeans(npatch, alt=True)
    t1 = time.time()
    assert len(patches) == cat.ntot
    assert min(patches) == 0
    assert max(patches) == npatch - 1

    cen = np.array([xyz[patches == i].mean(axis=0) for i in range(npatch)])
    inertia = np.array(
        [np.sum((xyz[patches == i] - cen[i])**2) for i in range(npatch)])
    sizes = np.array(
        [np.mean((xyz[patches == i] - cen[i])**2) for i in range(npatch)])**0.5
    sizes *= 180. / np.pi * 60.  # convert to arcmin
    counts = np.array([np.sum(patches == i) for i in range(npatch)])

    print('With alternate algorithm:')
    print('time = ', t1 - t0)
    print('total inertia = ', np.sum(inertia))
    print('mean inertia = ', np.mean(inertia))
    print('rms inertia = ', np.std(inertia))
    print('mean size = ', np.mean(sizes))
    print('rms size = ', np.std(sizes))
    assert np.sum(
        inertia
    ) < 200.  # Total shouldn't increase much. (And often decreases.)
    assert np.std(inertia) < 0.1 * np.mean(
        inertia)  # rms should be even smaller here.
    assert np.std(sizes) < 0.1 * np.mean(
        sizes)  # This is only a little bit smaller.

    # This doesn't keep the counts as equal as the standard algorithm.
    print('mean counts = ', np.mean(counts))
    print('min counts = ', np.min(counts))
    print('max counts = ', np.max(counts))

    # Finally, use a field with lots of top level cells to check the other branch in
    # InitializeCenters.
    field = cat.getNField(min_top=10)
    t0 = time.time()
    patches = field.run_kmeans(npatch)
    t1 = time.time()
    assert len(patches) == cat.ntot
    assert min(patches) == 0
    assert max(patches) == npatch - 1

    cen = np.array([xyz[patches == i].mean(axis=0) for i in range(npatch)])
    inertia = np.array(
        [np.sum((xyz[patches == i] - cen[i])**2) for i in range(npatch)])
    sizes = np.array(
        [np.mean((xyz[patches == i] - cen[i])**2) for i in range(npatch)])**0.5
    sizes *= 180. / np.pi * 60.  # convert to arcmin
    counts = np.array([np.sum(patches == i) for i in range(npatch)])

    # This doesn't give as good an initialization, so these are a bit worse usually.
    print('With min_top=10:')
    print('time = ', t1 - t0)
    print('total inertia = ', np.sum(inertia))
    print('mean inertia = ', np.mean(inertia))
    print('rms inertia = ', np.std(inertia))
    print('mean size = ', np.mean(sizes))
    print('rms size = ', np.std(sizes))
    assert np.sum(inertia) < 210.
    assert np.std(inertia) < 0.4 * np.mean(
        inertia)  # I've seen over 0.3 x mean here.
    assert np.std(sizes) < 0.15 * np.mean(sizes)
    print('mean counts = ', np.mean(counts))
    print('min counts = ', np.min(counts))
    print('max counts = ', np.max(counts))
Beispiel #10
0
def test_perp_minmax():
    """This test is based on a bug report from Erika Wagoner where the lowest bins were
    getting spuriously high w(rp) values.  It stemmed from a subtlety about how large
    rp can be compared to minsep.  The maximum rp is more than just rp + s1 + s2.
    So this test checks that when the min and max are expanded a bit, the number of pairs
    doesn't change much in the bins that used to be the min and max.
    """
    # Just use Erika's files for data and rand.
    config = {
        'ra_col' : 1,
        'dec_col' : 2,
        'ra_units' : 'deg',
        'dec_units' : 'deg',
        'r_col' : 3,
        'min_sep' : 20,
        'bin_size' : 0.036652,
        'nbins' : 50,
        'verbose' : 1
    }

    # Speed up for nosetests runs
    if __name__ != "__main__":
        config['nbins'] = 5
        config['bin_size'] = 0.1

    get_from_wiki('nn_perp_data.dat')
    dcat = treecorr.Catalog('data/nn_perp_data.dat', config)

    dd1 = treecorr.NNCorrelation(config)
    dd1.process(dcat, metric='Rperp')

    lower_min_sep = config['min_sep'] * numpy.exp(-2.*config['bin_size'])
    more_nbins = config['nbins'] + 4
    dd2 = treecorr.NNCorrelation(config, min_sep=lower_min_sep, nbins=more_nbins)
    dd2.process(dcat, metric='Rperp')

    print('dd1 npairs = ',dd1.npairs)
    print('dd2 npairs = ',dd2.npairs[2:-2])
    # First a basic sanity check.  The values not near the edge should be identical.
    numpy.testing.assert_equal(dd1.npairs[2:-2], dd2.npairs[4:-4])
    # The edge bins may differ slightly from the binning approximations (bin_slop and such),
    # but the differences should be very small.  (When Erika reported the problem, the differences
    # were a few percent, which ended up making a bit difference in the correlation function.)
    numpy.testing.assert_almost_equal( dd1.npairs / dd2.npairs[2:-2], 1., decimal=4)

    if __name__ == '__main__':
        # If we're running from the command line, go ahead and finish the calculation
        # This catalog has 10^6 objects, which takes quite a while.  I should really investigate
        # how to speed up the Rperp distance calculation.  Probably by having a faster over-
        # and under-estimate first, and then only do the full calculation when it seems like we
        # will actually need it.
        # Anyway, until then, let's not take forever by using last_row=200000
        get_from_wiki('nn_perp_rand.dat')
        rcat = treecorr.Catalog('data/nn_perp_rand.dat', config, last_row=200000)

        rr1 = treecorr.NNCorrelation(config)
        rr1.process(rcat, metric='Rperp')
        rr2 = treecorr.NNCorrelation(config, min_sep=lower_min_sep, nbins=more_nbins)
        rr2.process(rcat, metric='Rperp')
        print('rr1 npairs = ',rr1.npairs)
        print('rr2 npairs = ',rr2.npairs[2:-2])
        numpy.testing.assert_almost_equal( rr1.npairs / rr2.npairs[2:-2], 1., decimal=4)

        dr1 = treecorr.NNCorrelation(config)
        dr1.process(dcat, rcat, metric='Rperp')
        dr2 = treecorr.NNCorrelation(config, min_sep=lower_min_sep, nbins=more_nbins)
        dr2.process(dcat, rcat, metric='Rperp')
        print('dr1 npairs = ',dr1.npairs)
        print('dr2 npairs = ',dr2.npairs[2:-2])
        numpy.testing.assert_almost_equal( dr1.npairs / dr2.npairs[2:-2], 1., decimal=4)

        xi1, varxi1 = dd1.calculateXi(rr1, dr1)
        xi2, varxi2 = dd2.calculateXi(rr2, dr2)
        print('xi1 = ',xi1)
        print('xi2 = ',xi2[2:-2])
        numpy.testing.assert_almost_equal( xi1 / xi2[2:-2], 1., decimal=2)

        # Check that we get the same result with the corr2 executable.
        import subprocess
        corr2_exe = get_script_name('corr2')
        p = subprocess.Popen( [corr2_exe,"nn_rperp.yaml"] )
        p.communicate()
        corr2_output = numpy.genfromtxt(os.path.join('output','nn_rperp.out'),names=True,skip_header=1)
        print('xi = ',xi1)
        print('from corr2 output = ',corr2_output['xi'])
        print('ratio = ',corr2_output['xi']/xi1)
        print('diff = ',corr2_output['xi']-xi1)
        numpy.testing.assert_almost_equal(corr2_output['xi']/xi1, 1., decimal=3)
Beispiel #11
0
def test_aardvark():

    # Eric Suchyta did a brute force calculation of the Aardvark catalog, so it is useful to
    # compare the output from my code with that.

    get_from_wiki('Aardvark.fit')
    file_name = os.path.join('data', 'Aardvark.fit')
    config = treecorr.read_config('Aardvark.params')
    cat1 = treecorr.Catalog(file_name, config)
    gg = treecorr.GGCorrelation(config)
    gg.process(cat1)

    direct_file_name = os.path.join('data', 'Aardvark.direct')
    direct_data = numpy.genfromtxt(direct_file_name)
    direct_xip = direct_data[:, 3]
    direct_xim = direct_data[:, 4]

    #print('gg.xip = ',gg.xip)
    #print('direct.xip = ',direct_xip)

    xip_err = gg.xip - direct_xip
    print('xip_err = ', xip_err)
    print('max = ', max(abs(xip_err)))
    assert max(abs(xip_err)) < 2.e-7
    print('xip_im = ', gg.xip_im)
    print('max = ', max(abs(gg.xip_im)))
    assert max(abs(gg.xip_im)) < 3.e-7

    xim_err = gg.xim - direct_xim
    print('xim_err = ', xim_err)
    print('max = ', max(abs(xim_err)))
    assert max(abs(xim_err)) < 1.e-7
    print('xim_im = ', gg.xim_im)
    print('max = ', max(abs(gg.xim_im)))
    assert max(abs(gg.xim_im)) < 1.e-7

    # However, after some back and forth about the calculation, we concluded that Eric hadn't
    # done the spherical trig correctly to get the shears relative to the great circle joining
    # the two positions.  So let's compare with my own brute force calculation (i.e. using
    # bin_slop = 0):
    # This also has the advantage that the radial bins are done the same way -- uniformly
    # spaced in log of the chord distance, rather than the great circle distance.

    bs0_file_name = os.path.join('data', 'Aardvark.bs0')
    bs0_data = numpy.genfromtxt(bs0_file_name)
    bs0_xip = bs0_data[:, 2]
    bs0_xim = bs0_data[:, 3]

    #print('gg.xip = ',gg.xip)
    #print('bs0.xip = ',bs0_xip)

    xip_err = gg.xip - bs0_xip
    print('xip_err = ', xip_err)
    print('max = ', max(abs(xip_err)))
    assert max(abs(xip_err)) < 1.e-7

    xim_err = gg.xim - bs0_xim
    print('xim_err = ', xim_err)
    print('max = ', max(abs(xim_err)))
    assert max(abs(xim_err)) < 5.e-8

    # Check that we get the same result using the corr2 executable:
    # Note: This is the only test of the corr2 executable that we do with nosetests.
    # The other similar tests are blocked out with: if __name__ == '__main__':
    import subprocess
    corr2_exe = get_script_name('corr2')
    p = subprocess.Popen([corr2_exe, "Aardvark.params"])
    p.communicate()
    corr2_output = numpy.genfromtxt(os.path.join('output', 'Aardvark.out'),
                                    names=True)
    print('gg.xip = ', gg.xip)
    print('from corr2 output = ', corr2_output['xip'])
    print('ratio = ', corr2_output['xip'] / gg.xip)
    print('diff = ', corr2_output['xip'] - gg.xip)
    numpy.testing.assert_almost_equal(corr2_output['xip'] / gg.xip,
                                      1.,
                                      decimal=3)

    print('gg.xim = ', gg.xim)
    print('from corr2 output = ', corr2_output['xim'])
    print('ratio = ', corr2_output['xim'] / gg.xim)
    print('diff = ', corr2_output['xim'] - gg.xim)
    numpy.testing.assert_almost_equal(corr2_output['xim'] / gg.xim,
                                      1.,
                                      decimal=3)

    print('xip_im from corr2 output = ', corr2_output['xip_im'])
    print('max err = ', max(abs(corr2_output['xip_im'])))
    assert max(abs(corr2_output['xip_im'])) < 3.e-7
    print('xim_im from corr2 output = ', corr2_output['xim_im'])
    print('max err = ', max(abs(corr2_output['xim_im'])))
    assert max(abs(corr2_output['xim_im'])) < 1.e-7

    # As bin_slop decreases, the agreement should get even better.
    # This test is slow, so only do it if running test_gg.py directly.
    if __name__ == '__main__':
        config['bin_slop'] = 0.2
        gg = treecorr.GGCorrelation(config)
        gg.process(cat1)

        #print('gg.xip = ',gg.xip)
        #print('bs0.xip = ',bs0_xip)

        xip_err = gg.xip - bs0_xip
        print('xip_err = ', xip_err)
        print('max = ', max(abs(xip_err)))
        assert max(abs(xip_err)) < 1.e-8

        xim_err = gg.xim - bs0_xim
        print('xim_err = ', xim_err)
        print('max = ', max(abs(xim_err)))
        assert max(abs(xim_err)) < 1.e-8
Beispiel #12
0
def test_aardvark():

    # Eric Suchyta did a brute force calculation of the Aardvark catalog, so it is useful to
    # compare the output from my code with that.

    get_from_wiki('Aardvark.fit')
    file_name = os.path.join('data','Aardvark.fit')
    config = treecorr.read_config('Aardvark.yaml')
    cat1 = treecorr.Catalog(file_name, config)
    gg = treecorr.GGCorrelation(config)
    gg.process(cat1)

    direct_file_name = os.path.join('data','Aardvark.direct')
    direct_data = numpy.genfromtxt(direct_file_name)
    direct_xip = direct_data[:,3]
    direct_xim = direct_data[:,4]

    #print('gg.xip = ',gg.xip)
    #print('direct.xip = ',direct_xip)

    xip_err = gg.xip - direct_xip
    print('xip_err = ',xip_err)
    print('max = ',max(abs(xip_err)))
    assert max(abs(xip_err)) < 2.e-7
    print('xip_im = ',gg.xip_im)
    print('max = ',max(abs(gg.xip_im)))
    assert max(abs(gg.xip_im)) < 3.e-7

    xim_err = gg.xim - direct_xim
    print('xim_err = ',xim_err)
    print('max = ',max(abs(xim_err)))
    assert max(abs(xim_err)) < 1.e-7
    print('xim_im = ',gg.xim_im)
    print('max = ',max(abs(gg.xim_im)))
    assert max(abs(gg.xim_im)) < 1.e-7

    # However, after some back and forth about the calculation, we concluded that Eric hadn't
    # done the spherical trig correctly to get the shears relative to the great circle joining
    # the two positions.  So let's compare with my own brute force calculation (i.e. using
    # bin_slop = 0):
    # This also has the advantage that the radial bins are done the same way -- uniformly
    # spaced in log of the chord distance, rather than the great circle distance.

    bs0_file_name = os.path.join('data','Aardvark.bs0')
    bs0_data = numpy.genfromtxt(bs0_file_name)
    bs0_xip = bs0_data[:,2]
    bs0_xim = bs0_data[:,3]

    #print('gg.xip = ',gg.xip)
    #print('bs0.xip = ',bs0_xip)

    xip_err = gg.xip - bs0_xip
    print('xip_err = ',xip_err)
    print('max = ',max(abs(xip_err)))
    assert max(abs(xip_err)) < 1.e-7

    xim_err = gg.xim - bs0_xim
    print('xim_err = ',xim_err)
    print('max = ',max(abs(xim_err)))
    assert max(abs(xim_err)) < 5.e-8

    # Check that we get the same result using the corr2 executable:
    # Note: This is the only test of the corr2 executable that we do with nosetests.
    # The other similar tests are blocked out with: if __name__ == '__main__':
    import subprocess
    corr2_exe = get_script_name('corr2')
    p = subprocess.Popen( [corr2_exe,"Aardvark.yaml"] )
    p.communicate()
    corr2_output = numpy.genfromtxt(os.path.join('output','Aardvark.out'), names=True)
    print('gg.xip = ',gg.xip)
    print('from corr2 output = ',corr2_output['xip'])
    print('ratio = ',corr2_output['xip']/gg.xip)
    print('diff = ',corr2_output['xip']-gg.xip)
    numpy.testing.assert_almost_equal(corr2_output['xip']/gg.xip, 1., decimal=3)

    print('gg.xim = ',gg.xim)
    print('from corr2 output = ',corr2_output['xim'])
    print('ratio = ',corr2_output['xim']/gg.xim)
    print('diff = ',corr2_output['xim']-gg.xim)
    numpy.testing.assert_almost_equal(corr2_output['xim']/gg.xim, 1., decimal=3)

    print('xip_im from corr2 output = ',corr2_output['xip_im'])
    print('max err = ',max(abs(corr2_output['xip_im'])))
    assert max(abs(corr2_output['xip_im'])) < 3.e-7
    print('xim_im from corr2 output = ',corr2_output['xim_im'])
    print('max err = ',max(abs(corr2_output['xim_im'])))
    assert max(abs(corr2_output['xim_im'])) < 1.e-7

    # As bin_slop decreases, the agreement should get even better.
    # This test is slow, so only do it if running test_gg.py directly.
    if __name__ == '__main__':
        config['bin_slop'] = 0.2
        gg = treecorr.GGCorrelation(config)
        gg.process(cat1)

        #print('gg.xip = ',gg.xip)
        #print('bs0.xip = ',bs0_xip)

        xip_err = gg.xip - bs0_xip
        print('xip_err = ',xip_err)
        print('max = ',max(abs(xip_err)))
        assert max(abs(xip_err)) < 1.e-8

        xim_err = gg.xim - bs0_xim
        print('xim_err = ',xim_err)
        print('max = ',max(abs(xim_err)))
        assert max(abs(xim_err)) < 1.e-8
Beispiel #13
0
def test_fits_reader():
    try:
        import fitsio
    except ImportError:
        print('Skipping FitsReader tests, since fitsio not installed.')
        return

    get_from_wiki('Aardvark.fit')
    r = FitsReader(os.path.join('data', 'Aardvark.fit'))

    # Check things not allowed if not in context
    with assert_raises(RuntimeError):
        r.read(['RA'], slice(0, 10, 2), 1)
    with assert_raises(RuntimeError):
        r.read('RA')
    with assert_raises(RuntimeError):
        r.row_count('DEC', 1)
    with assert_raises(RuntimeError):
        r.row_count()
    with assert_raises(RuntimeError):
        r.names(1)
    with assert_raises(RuntimeError):
        r.names()
    with assert_raises(RuntimeError):
        1 in r

    with r:
        assert_raises(ValueError, r.check_valid_ext, 'invalid')
        assert_raises(ValueError, r.check_valid_ext, 0)
        r.check_valid_ext('AARDWOLF')
        r.check_valid_ext(1)

        # Default ext is 1
        assert r.default_ext == 1

        # Default ext is "in" reader
        assert 1 in r

        # Probably can slice, but depends on installed fitsio version
        assert r.can_slice == (fitsio.__version__ > '1.0.6')

        s = slice(0, 10, 2)
        for ext in [1, 'AARDWOLF']:
            data = r.read(['RA'], s, ext)
            dec = r.read('DEC', s, ext)
            assert data['RA'].size == 5
            assert dec.size == 5

            assert r.row_count('RA', ext) == 390935
            assert r.row_count('GAMMA1', ext) == 390935
            assert set(r.names(ext)) == set(
                "INDEX RA DEC Z EPSILON GAMMA1 GAMMA2 KAPPA MU".split())
            assert set(r.names(ext)) == set(r.names())

        # Can read without slice or ext to use defaults
        assert r.row_count() == 390935
        g2 = r.read('GAMMA2')
        assert len(g2) == 390935
        d = r.read(['KAPPA', 'MU'])
        assert len(d['KAPPA']) == 390935
        assert len(d['MU']) == 390935

        # check we can also index by integer, not just number
        d = r.read(['DEC'], np.arange(10), 'AARDWOLF')
        assert d.size == 10

        if sys.version_info < (3, ): return  # mock only available on python 3
        from unittest import mock

    # Again check things not allowed if not in context
    with assert_raises(RuntimeError):
        r.read(['RA'], slice(0, 10, 2), 1)
    with assert_raises(RuntimeError):
        r.read('RA')
    with assert_raises(RuntimeError):
        r.row_count('DEC', 1)
    with assert_raises(RuntimeError):
        r.row_count()
    with assert_raises(RuntimeError):
        r.names(1)
    with assert_raises(RuntimeError):
        r.names()
    with assert_raises(RuntimeError):
        1 in r

    # Regardless of the system's fitsio version, check the two cases in code.
    with mock.patch('fitsio.__version__', '1.0.6'):
        with FitsReader(os.path.join('data', 'Aardvark.fit')) as r:
            assert not r.can_slice
    with mock.patch('fitsio.__version__', '1.1.0'):
        with FitsReader(os.path.join('data', 'Aardvark.fit')) as r:
            assert r.can_slice
Beispiel #14
0
def test_hdf_reader():
    try:
        import h5py
    except ImportError:
        print('Skipping HdfReader tests, since h5py not installed.')
        return

    get_from_wiki('Aardvark.hdf5')
    r = HdfReader(os.path.join('data', 'Aardvark.hdf5'))

    # Check things not allowed if not in context
    with assert_raises(RuntimeError):
        r.read(['RA'], slice(0, 10, 2), '/')
    with assert_raises(RuntimeError):
        r.read('RA')
    with assert_raises(RuntimeError):
        r.row_count('DEC', '/')
    with assert_raises(RuntimeError):
        r.row_count('DEC')
    with assert_raises(RuntimeError):
        r.names('/')
    with assert_raises(RuntimeError):
        r.names()
    with assert_raises(RuntimeError):
        '/' in r

    with r:

        # '/' is the only extension in this file.
        # TODO: Add an hdf5 example with other valid choices for ext
        assert_raises(ValueError, r.check_valid_ext, 'invalid')
        r.check_valid_ext('/')

        # Default ext is '/'
        assert r.default_ext == '/'

        # Default ext is "in" reader
        assert '/' in r

        # Can always slice
        assert r.can_slice

        s = slice(0, 10, 2)
        data = r.read(['RA'], s)
        dec = r.read('DEC', s)
        assert data['RA'].size == 5
        assert dec.size == 5

        assert r.row_count('RA') == 390935
        assert r.row_count('RA', '/') == 390935
        assert r.row_count('GAMMA1') == 390935
        # Unlike the other readers, this needs a column name.
        assert_raises(TypeError, r.row_count)
        assert set(r.names()) == set(
            "INDEX RA DEC Z EPSILON GAMMA1 GAMMA2 KAPPA MU".split())
        assert set(r.names('/')) == set(r.names())

    # Again check things not allowed if not in context
    with assert_raises(RuntimeError):
        r.read(['RA'], slice(0, 10, 2), '/')
    with assert_raises(RuntimeError):
        r.read('RA')
    with assert_raises(RuntimeError):
        r.row_count('DEC', '/')
    with assert_raises(RuntimeError):
        r.row_count('DEC')
    with assert_raises(RuntimeError):
        r.names('/')
    with assert_raises(RuntimeError):
        r.names()
    with assert_raises(RuntimeError):
        '/' in r
Beispiel #15
0
def test_dessv():
    try:
        import fitsio
    except ImportError:
        print('Skipping dessv test, since fitsio is not installed')
        return

    #treecorr.set_omp_threads(1);
    get_from_wiki('des_sv.fits')
    file_name = os.path.join('data','des_sv.fits')
    cat = treecorr.Catalog(file_name, ra_col='ra', dec_col='dec', ra_units='deg', dec_units='deg')

    # Use an odd number to make sure we force some of the shuffle bits in InitializeCenters
    # to happen.
    npatch = 43
    field = cat.getNField()
    t0 = time.time()
    patches = field.run_kmeans(npatch)
    t1 = time.time()
    print('patches = ',np.unique(patches))
    assert len(patches) == cat.ntot
    assert min(patches) == 0
    assert max(patches) == npatch-1

    # KMeans minimizes the total inertia.
    # Check this value and the rms size, which should also be quite small.
    xyz = np.array([cat.x, cat.y, cat.z]).T
    cen = np.array([xyz[patches==i].mean(axis=0) for i in range(npatch)])
    inertia = np.array([np.sum((xyz[patches==i] - cen[i])**2) for i in range(npatch)])
    sizes = np.array([np.mean((xyz[patches==i] - cen[i])**2) for i in range(npatch)])**0.5
    sizes *= 180. / np.pi * 60.  # convert to arcmin
    counts = np.array([np.sum(patches==i) for i in range(npatch)])

    print('With standard algorithm:')
    print('time = ',t1-t0)
    print('total inertia = ',np.sum(inertia))
    print('mean inertia = ',np.mean(inertia))
    print('rms inertia = ',np.std(inertia))
    print('mean size = ',np.mean(sizes))
    print('rms size = ',np.std(sizes))
    assert np.sum(inertia) < 200.  # This is specific to this particular field and npatch.
    assert np.std(inertia) < 0.2 * np.mean(inertia)  # rms is usually small  mean
    assert np.std(sizes) < 0.1 * np.mean(sizes)  # sizes have even less spread usually.

    # Should all have similar number of points.  Nothing is required here though.
    print('mean counts = ',np.mean(counts))
    print('min counts = ',np.min(counts))
    print('max counts = ',np.max(counts))

    # Check the alternate algorithm.  rms inertia should be lower.
    t0 = time.time()
    patches = field.run_kmeans(npatch, alt=True)
    t1 = time.time()
    assert len(patches) == cat.ntot
    assert min(patches) == 0
    assert max(patches) == npatch-1

    cen = np.array([xyz[patches==i].mean(axis=0) for i in range(npatch)])
    inertia = np.array([np.sum((xyz[patches==i] - cen[i])**2) for i in range(npatch)])
    sizes = np.array([np.mean((xyz[patches==i] - cen[i])**2) for i in range(npatch)])**0.5
    sizes *= 180. / np.pi * 60.  # convert to arcmin
    counts = np.array([np.sum(patches==i) for i in range(npatch)])

    print('With alternate algorithm:')
    print('time = ',t1-t0)
    print('total inertia = ',np.sum(inertia))
    print('mean inertia = ',np.mean(inertia))
    print('rms inertia = ',np.std(inertia))
    print('mean size = ',np.mean(sizes))
    print('rms size = ',np.std(sizes))
    assert np.sum(inertia) < 200.  # Total shouldn't increase much. (And often decreases.)
    assert np.std(inertia) < 0.1 * np.mean(inertia)  # rms should be even smaller here.
    assert np.std(sizes) < 0.1 * np.mean(sizes)  # This is only a little bit smaller.

    # This doesn't keep the counts as equal as the standard algorithm.
    print('mean counts = ',np.mean(counts))
    print('min counts = ',np.min(counts))
    print('max counts = ',np.max(counts))

    # Finally, use a field with lots of top level cells to check the other branch in
    # InitializeCenters.
    field = cat.getNField(min_top=10)
    t0 = time.time()
    patches = field.run_kmeans(npatch)
    t1 = time.time()
    assert len(patches) == cat.ntot
    assert min(patches) == 0
    assert max(patches) == npatch-1

    cen = np.array([xyz[patches==i].mean(axis=0) for i in range(npatch)])
    inertia = np.array([np.sum((xyz[patches==i] - cen[i])**2) for i in range(npatch)])
    sizes = np.array([np.mean((xyz[patches==i] - cen[i])**2) for i in range(npatch)])**0.5
    sizes *= 180. / np.pi * 60.  # convert to arcmin
    counts = np.array([np.sum(patches==i) for i in range(npatch)])

    # This doesn't give as good an initialization, so these are a bit worse usually.
    print('With min_top=10:')
    print('time = ',t1-t0)
    print('total inertia = ',np.sum(inertia))
    print('mean inertia = ',np.mean(inertia))
    print('rms inertia = ',np.std(inertia))
    print('mean size = ',np.mean(sizes))
    print('rms size = ',np.std(sizes))
    assert np.sum(inertia) < 210.
    assert np.std(inertia) < 0.4 * np.mean(inertia)  # I've seen over 0.3 x mean here.
    assert np.std(sizes) < 0.1 * np.mean(sizes)
    print('mean counts = ',np.mean(counts))
    print('min counts = ',np.min(counts))
    print('max counts = ',np.max(counts))