testbed/astropy__astropy/astropy/visualization/tests/test_histogram.py

# Licensed under a 3-clause BSD style license - see LICENSE.rst


from numpy.testing import assert_allclose

try:
    import matplotlib.pyplot as plt
    HAS_PLT = True
except ImportError:
    HAS_PLT = False

try:
    import scipy  # noqa
    HAS_SCIPY = True
except ImportError:
    HAS_SCIPY = False

import pytest
import numpy as np

from astropy.visualization import hist
from astropy.stats import histogram


@pytest.mark.skipif('not HAS_PLT')
def test_hist_basic(rseed=0):
    rng = np.random.RandomState(rseed)
    x = rng.randn(100)

    for range in [None, (-2, 2)]:
        n1, bins1, patches1 = plt.hist(x, 10, range=range)
        n2, bins2, patches2 = hist(x, 10, range=range)

        assert_allclose(n1, n2)
        assert_allclose(bins1, bins2)


@pytest.mark.skipif('not HAS_PLT')
def test_hist_specify_ax(rseed=0):
    rng = np.random.RandomState(rseed)
    x = rng.randn(100)

    fig, ax = plt.subplots(2)
    n1, bins1, patches1 = hist(x, 10, ax=ax[0])
    assert patches1[0].axes is ax[0]

    n2, bins2, patches2 = hist(x, 10, ax=ax[1])
    assert patches2[0].axes is ax[1]


@pytest.mark.skipif('not HAS_PLT')
def test_hist_autobin(rseed=0):
    rng = np.random.RandomState(rseed)
    x = rng.randn(100)

    # 'knuth' bintype depends on scipy that is optional dependency
    if HAS_SCIPY:
        bintypes = [10, np.arange(-3, 3, 10), 'knuth', 'scott',
                    'freedman', 'blocks']
    else:
        bintypes = [10, np.arange(-3, 3, 10), 'scott',
                    'freedman', 'blocks']

    for bintype in bintypes:
        for range in [None, (-3, 3)]:
            n1, bins1 = histogram(x, bintype, range=range)
            n2, bins2, patches = hist(x, bintype, range=range)
            assert_allclose(n1, n2)
            assert_allclose(bins1, bins2)


def test_histogram_pathological_input():
    # Regression test for https://github.com/astropy/astropy/issues/7758

    # The key feature of the data below is that one of the points is very,
    # very different than the rest. That leads to a large number of bins.
    data = [9.99999914e+05, -8.31312483e-03, 6.52755852e-02, 1.43104653e-03,
            -2.26311017e-02, 2.82660007e-03, 1.80307521e-02, 9.26294279e-03,
            5.06606026e-02, 2.05418011e-03]

    with pytest.raises(ValueError):
        hist(data, bins='freedman', max_bins=10000)