test_collections.py

"""
Tests specific to the collections module.
"""
import io
import platform

import numpy as np
from numpy.testing import assert_array_equal, assert_array_almost_equal
import pytest

import matplotlib.pyplot as plt
import matplotlib.collections as mcollections
import matplotlib.transforms as mtransforms
from matplotlib.collections import Collection, LineCollection, EventCollection
from matplotlib.testing.decorators import image_comparison


def generate_EventCollection_plot():
    '''
    generate the initial collection and plot it
    '''
    positions = np.array([0., 1., 2., 3., 5., 8., 13., 21.])
    extra_positions = np.array([34., 55., 89.])
    orientation = 'horizontal'
    lineoffset = 1
    linelength = .5
    linewidth = 2
    color = [1, 0, 0, 1]
    linestyle = 'solid'
    antialiased = True

    coll = EventCollection(positions,
                           orientation=orientation,
                           lineoffset=lineoffset,
                           linelength=linelength,
                           linewidth=linewidth,
                           color=color,
                           linestyle=linestyle,
                           antialiased=antialiased
                           )

    fig = plt.figure()
    splt = fig.add_subplot(1, 1, 1)
    splt.add_collection(coll)
    splt.set_title('EventCollection: default')
    props = {'positions': positions,
             'extra_positions': extra_positions,
             'orientation': orientation,
             'lineoffset': lineoffset,
             'linelength': linelength,
             'linewidth': linewidth,
             'color': color,
             'linestyle': linestyle,
             'antialiased': antialiased
             }
    splt.set_xlim(-1, 22)
    splt.set_ylim(0, 2)
    return splt, coll, props


@image_comparison(['EventCollection_plot__default'])
def test__EventCollection__get_segments():
    '''
    check to make sure the default segments have the correct coordinates
    '''
    _, coll, props = generate_EventCollection_plot()
    check_segments(coll,
                   props['positions'],
                   props['linelength'],
                   props['lineoffset'],
                   props['orientation'])


def test__EventCollection__get_positions():
    '''
    check to make sure the default positions match the input positions
    '''
    _, coll, props = generate_EventCollection_plot()
    np.testing.assert_array_equal(props['positions'], coll.get_positions())


def test__EventCollection__get_orientation():
    '''
    check to make sure the default orientation matches the input
    orientation
    '''
    _, coll, props = generate_EventCollection_plot()
    assert props['orientation'] == coll.get_orientation()


def test__EventCollection__is_horizontal():
    '''
    check to make sure the default orientation matches the input
    orientation
    '''
    _, coll, _ = generate_EventCollection_plot()
    assert coll.is_horizontal()


def test__EventCollection__get_linelength():
    '''
    check to make sure the default linelength matches the input linelength
    '''
    _, coll, props = generate_EventCollection_plot()
    assert props['linelength'] == coll.get_linelength()


def test__EventCollection__get_lineoffset():
    '''
    check to make sure the default lineoffset matches the input lineoffset
    '''
    _, coll, props = generate_EventCollection_plot()
    assert props['lineoffset'] == coll.get_lineoffset()


def test__EventCollection__get_linestyle():
    '''
    check to make sure the default linestyle matches the input linestyle
    '''
    _, coll, _ = generate_EventCollection_plot()
    assert coll.get_linestyle() == [(None, None)]


def test__EventCollection__get_color():
    '''
    check to make sure the default color matches the input color
    '''
    _, coll, props = generate_EventCollection_plot()
    np.testing.assert_array_equal(props['color'], coll.get_color())
    check_allprop_array(coll.get_colors(), props['color'])


@image_comparison(['EventCollection_plot__set_positions'])
def test__EventCollection__set_positions():
    '''
    check to make sure set_positions works properly
    '''
    splt, coll, props = generate_EventCollection_plot()
    new_positions = np.hstack([props['positions'], props['extra_positions']])
    coll.set_positions(new_positions)
    np.testing.assert_array_equal(new_positions, coll.get_positions())
    check_segments(coll, new_positions,
                   props['linelength'],
                   props['lineoffset'],
                   props['orientation'])
    splt.set_title('EventCollection: set_positions')
    splt.set_xlim(-1, 90)


@image_comparison(['EventCollection_plot__add_positions'])
def test__EventCollection__add_positions():
    '''
    check to make sure add_positions works properly
    '''
    splt, coll, props = generate_EventCollection_plot()
    new_positions = np.hstack([props['positions'],
                               props['extra_positions'][0]])
    coll.add_positions(props['extra_positions'][0])
    np.testing.assert_array_equal(new_positions, coll.get_positions())
    check_segments(coll,
                   new_positions,
                   props['linelength'],
                   props['lineoffset'],
                   props['orientation'])
    splt.set_title('EventCollection: add_positions')
    splt.set_xlim(-1, 35)


@image_comparison(['EventCollection_plot__append_positions'])
def test__EventCollection__append_positions():
    '''
    check to make sure append_positions works properly
    '''
    splt, coll, props = generate_EventCollection_plot()
    new_positions = np.hstack([props['positions'],
                               props['extra_positions'][2]])
    coll.append_positions(props['extra_positions'][2])
    np.testing.assert_array_equal(new_positions, coll.get_positions())
    check_segments(coll,
                   new_positions,
                   props['linelength'],
                   props['lineoffset'],
                   props['orientation'])
    splt.set_title('EventCollection: append_positions')
    splt.set_xlim(-1, 90)


@image_comparison(['EventCollection_plot__extend_positions'])
def test__EventCollection__extend_positions():
    '''
    check to make sure extend_positions works properly
    '''
    splt, coll, props = generate_EventCollection_plot()
    new_positions = np.hstack([props['positions'],
                               props['extra_positions'][1:]])
    coll.extend_positions(props['extra_positions'][1:])
    np.testing.assert_array_equal(new_positions, coll.get_positions())
    check_segments(coll,
                   new_positions,
                   props['linelength'],
                   props['lineoffset'],
                   props['orientation'])
    splt.set_title('EventCollection: extend_positions')
    splt.set_xlim(-1, 90)


@image_comparison(['EventCollection_plot__switch_orientation'])
def test__EventCollection__switch_orientation():
    '''
    check to make sure switch_orientation works properly
    '''
    splt, coll, props = generate_EventCollection_plot()
    new_orientation = 'vertical'
    coll.switch_orientation()
    assert new_orientation == coll.get_orientation()
    assert not coll.is_horizontal()
    new_positions = coll.get_positions()
    check_segments(coll,
                   new_positions,
                   props['linelength'],
                   props['lineoffset'], new_orientation)
    splt.set_title('EventCollection: switch_orientation')
    splt.set_ylim(-1, 22)
    splt.set_xlim(0, 2)


@image_comparison(['EventCollection_plot__switch_orientation__2x'])
def test__EventCollection__switch_orientation_2x():
    '''
    check to make sure calling switch_orientation twice sets the
    orientation back to the default
    '''
    splt, coll, props = generate_EventCollection_plot()
    coll.switch_orientation()
    coll.switch_orientation()
    new_positions = coll.get_positions()
    assert props['orientation'] == coll.get_orientation()
    assert coll.is_horizontal()
    np.testing.assert_array_equal(props['positions'], new_positions)
    check_segments(coll,
                   new_positions,
                   props['linelength'],
                   props['lineoffset'],
                   props['orientation'])
    splt.set_title('EventCollection: switch_orientation 2x')


@image_comparison(['EventCollection_plot__set_orientation'])
def test__EventCollection__set_orientation():
    '''
    check to make sure set_orientation works properly
    '''
    splt, coll, props = generate_EventCollection_plot()
    new_orientation = 'vertical'
    coll.set_orientation(new_orientation)
    assert new_orientation == coll.get_orientation()
    assert not coll.is_horizontal()
    check_segments(coll,
                   props['positions'],
                   props['linelength'],
                   props['lineoffset'],
                   new_orientation)
    splt.set_title('EventCollection: set_orientation')
    splt.set_ylim(-1, 22)
    splt.set_xlim(0, 2)


@image_comparison(['EventCollection_plot__set_linelength'])
def test__EventCollection__set_linelength():
    '''
    check to make sure set_linelength works properly
    '''
    splt, coll, props = generate_EventCollection_plot()
    new_linelength = 15
    coll.set_linelength(new_linelength)
    assert new_linelength == coll.get_linelength()
    check_segments(coll,
                   props['positions'],
                   new_linelength,
                   props['lineoffset'],
                   props['orientation'])
    splt.set_title('EventCollection: set_linelength')
    splt.set_ylim(-20, 20)


@image_comparison(['EventCollection_plot__set_lineoffset'])
def test__EventCollection__set_lineoffset():
    '''
    check to make sure set_lineoffset works properly
    '''
    splt, coll, props = generate_EventCollection_plot()
    new_lineoffset = -5.
    coll.set_lineoffset(new_lineoffset)
    assert new_lineoffset == coll.get_lineoffset()
    check_segments(coll,
                   props['positions'],
                   props['linelength'],
                   new_lineoffset,
                   props['orientation'])
    splt.set_title('EventCollection: set_lineoffset')
    splt.set_ylim(-6, -4)


@image_comparison(['EventCollection_plot__set_linestyle'])
def test__EventCollection__set_linestyle():
    '''
    check to make sure set_linestyle works properly
    '''
    splt, coll, _ = generate_EventCollection_plot()
    new_linestyle = 'dashed'
    coll.set_linestyle(new_linestyle)
    assert coll.get_linestyle() == [(0, (6.0, 6.0))]
    splt.set_title('EventCollection: set_linestyle')


@image_comparison(['EventCollection_plot__set_ls_dash'], remove_text=True)
def test__EventCollection__set_linestyle_single_dash():
    '''
    check to make sure set_linestyle accepts a single dash pattern
    '''
    splt, coll, _ = generate_EventCollection_plot()
    new_linestyle = (0, (6., 6.))
    coll.set_linestyle(new_linestyle)
    assert coll.get_linestyle() == [(0, (6.0, 6.0))]
    splt.set_title('EventCollection: set_linestyle')


@image_comparison(['EventCollection_plot__set_linewidth'])
def test__EventCollection__set_linewidth():
    '''
    check to make sure set_linestyle works properly
    '''
    splt, coll, _ = generate_EventCollection_plot()
    new_linewidth = 5
    coll.set_linewidth(new_linewidth)
    assert coll.get_linewidth() == new_linewidth
    splt.set_title('EventCollection: set_linewidth')


@image_comparison(['EventCollection_plot__set_color'])
def test__EventCollection__set_color():
    '''
    check to make sure set_color works properly
    '''
    splt, coll, _ = generate_EventCollection_plot()
    new_color = np.array([0, 1, 1, 1])
    coll.set_color(new_color)
    np.testing.assert_array_equal(new_color, coll.get_color())
    check_allprop_array(coll.get_colors(), new_color)
    splt.set_title('EventCollection: set_color')


def check_segments(coll, positions, linelength, lineoffset, orientation):
    '''
    check to make sure all values in the segment are correct, given a
    particular set of inputs

    note: this is not a test, it is used by tests
    '''
    segments = coll.get_segments()
    if (orientation.lower() == 'horizontal'
            or orientation.lower() == 'none' or orientation is None):
        # if horizontal, the position in is in the y-axis
        pos1 = 1
        pos2 = 0
    elif orientation.lower() == 'vertical':
        # if vertical, the position in is in the x-axis
        pos1 = 0
        pos2 = 1
    else:
        raise ValueError("orientation must be 'horizontal' or 'vertical'")

    # test to make sure each segment is correct
    for i, segment in enumerate(segments):
        assert segment[0, pos1] == lineoffset + linelength / 2
        assert segment[1, pos1] == lineoffset - linelength / 2
        assert segment[0, pos2] == positions[i]
        assert segment[1, pos2] == positions[i]


def check_allprop_array(values, target):
    '''
    check to make sure all values match the given target if arrays

    note: this is not a test, it is used by tests
    '''
    for value in values:
        np.testing.assert_array_equal(value, target)


def test_null_collection_datalim():
    col = mcollections.PathCollection([])
    col_data_lim = col.get_datalim(mtransforms.IdentityTransform())
    assert_array_equal(col_data_lim.get_points(),
                       mtransforms.Bbox.null().get_points())


def test_add_collection():
    # Test if data limits are unchanged by adding an empty collection.
    # GitHub issue #1490, pull #1497.
    plt.figure()
    ax = plt.axes()
    coll = ax.scatter([0, 1], [0, 1])
    ax.add_collection(coll)
    bounds = ax.dataLim.bounds
    coll = ax.scatter([], [])
    assert ax.dataLim.bounds == bounds


def test_quiver_limits():
    ax = plt.axes()
    x, y = np.arange(8), np.arange(10)
    u = v = np.linspace(0, 10, 80).reshape(10, 8)
    q = plt.quiver(x, y, u, v)
    assert q.get_datalim(ax.transData).bounds == (0., 0., 7., 9.)

    plt.figure()
    ax = plt.axes()
    x = np.linspace(-5, 10, 20)
    y = np.linspace(-2, 4, 10)
    y, x = np.meshgrid(y, x)
    trans = mtransforms.Affine2D().translate(25, 32) + ax.transData
    plt.quiver(x, y, np.sin(x), np.cos(y), transform=trans)
    assert ax.dataLim.bounds == (20.0, 30.0, 15.0, 6.0)


def test_barb_limits():
    ax = plt.axes()
    x = np.linspace(-5, 10, 20)
    y = np.linspace(-2, 4, 10)
    y, x = np.meshgrid(y, x)
    trans = mtransforms.Affine2D().translate(25, 32) + ax.transData
    plt.barbs(x, y, np.sin(x), np.cos(y), transform=trans)
    # The calculated bounds are approximately the bounds of the original data,
    # this is because the entire path is taken into account when updating the
    # datalim.
    assert_array_almost_equal(ax.dataLim.bounds, (20, 30, 15, 6),
                              decimal=1)


@image_comparison(['EllipseCollection_test_image.png'], remove_text=True,
                  tol={'aarch64': 0.02}.get(platform.machine(), 0.0))
def test_EllipseCollection():
    # Test basic functionality
    fig, ax = plt.subplots()
    x = np.arange(4)
    y = np.arange(3)
    X, Y = np.meshgrid(x, y)
    XY = np.vstack((X.ravel(), Y.ravel())).T

    ww = X / x[-1]
    hh = Y / y[-1]
    aa = np.ones_like(ww) * 20  # first axis is 20 degrees CCW from x axis

    ec = mcollections.EllipseCollection(ww, hh, aa,
                                        units='x',
                                        offsets=XY,
                                        transOffset=ax.transData,
                                        facecolors='none')
    ax.add_collection(ec)
    ax.autoscale_view()


@image_comparison(['polycollection_close.png'], remove_text=True)
def test_polycollection_close():
    from mpl_toolkits.mplot3d import Axes3D

    vertsQuad = [
        [[0., 0.], [0., 1.], [1., 1.], [1., 0.]],
        [[0., 1.], [2., 3.], [2., 2.], [1., 1.]],
        [[2., 2.], [2., 3.], [4., 1.], [3., 1.]],
        [[3., 0.], [3., 1.], [4., 1.], [4., 0.]]]

    fig = plt.figure()
    ax = Axes3D(fig)

    colors = ['r', 'g', 'b', 'y', 'k']
    zpos = list(range(5))

    poly = mcollections.PolyCollection(
        vertsQuad * len(zpos), linewidth=0.25)
    poly.set_alpha(0.7)

    # need to have a z-value for *each* polygon = element!
    zs = []
    cs = []
    for z, c in zip(zpos, colors):
        zs.extend([z] * len(vertsQuad))
        cs.extend([c] * len(vertsQuad))

    poly.set_color(cs)

    ax.add_collection3d(poly, zs=zs, zdir='y')

    # axis limit settings:
    ax.set_xlim3d(0, 4)
    ax.set_zlim3d(0, 3)
    ax.set_ylim3d(0, 4)


@image_comparison(['regularpolycollection_rotate.png'], remove_text=True)
def test_regularpolycollection_rotate():
    xx, yy = np.mgrid[:10, :10]
    xy_points = np.transpose([xx.flatten(), yy.flatten()])
    rotations = np.linspace(0, 2*np.pi, len(xy_points))

    fig, ax = plt.subplots()
    for xy, alpha in zip(xy_points, rotations):
        col = mcollections.RegularPolyCollection(
            4, sizes=(100,), rotation=alpha,
            offsets=[xy], transOffset=ax.transData)
        ax.add_collection(col, autolim=True)
    ax.autoscale_view()


@image_comparison(['regularpolycollection_scale.png'], remove_text=True)
def test_regularpolycollection_scale():
    # See issue #3860

    class SquareCollection(mcollections.RegularPolyCollection):
        def __init__(self, **kwargs):
            super().__init__(4, rotation=np.pi/4., **kwargs)

        def get_transform(self):
            """Return transform scaling circle areas to data space."""
            ax = self.axes

            pts2pixels = 72.0 / ax.figure.dpi

            scale_x = pts2pixels * ax.bbox.width / ax.viewLim.width
            scale_y = pts2pixels * ax.bbox.height / ax.viewLim.height
            return mtransforms.Affine2D().scale(scale_x, scale_y)

    fig, ax = plt.subplots()

    xy = [(0, 0)]
    # Unit square has a half-diagonal of `1 / sqrt(2)`, so `pi * r**2`
    # equals...
    circle_areas = [np.pi / 2]
    squares = SquareCollection(sizes=circle_areas, offsets=xy,
                               transOffset=ax.transData)
    ax.add_collection(squares, autolim=True)
    ax.axis([-1, 1, -1, 1])


def test_picking():
    fig, ax = plt.subplots()
    col = ax.scatter([0], [0], [1000], picker=True)
    fig.savefig(io.BytesIO(), dpi=fig.dpi)

    class MouseEvent:
        pass
    event = MouseEvent()
    event.x = 325
    event.y = 240

    found, indices = col.contains(event)
    assert found
    assert_array_equal(indices['ind'], [0])


def test_linestyle_single_dashes():
    plt.scatter([0, 1, 2], [0, 1, 2], linestyle=(0., [2., 2.]))
    plt.draw()


@image_comparison(['size_in_xy.png'], remove_text=True)
def test_size_in_xy():
    fig, ax = plt.subplots()

    widths, heights, angles = (10, 10), 10, 0
    widths = 10, 10
    coords = [(10, 10), (15, 15)]
    e = mcollections.EllipseCollection(
        widths, heights, angles,
        units='xy',
        offsets=coords,
        transOffset=ax.transData)

    ax.add_collection(e)

    ax.set_xlim(0, 30)
    ax.set_ylim(0, 30)


def test_pandas_indexing(pd):

    # Should not fail break when faced with a
    # non-zero indexed series
    index = [11, 12, 13]
    ec = fc = pd.Series(['red', 'blue', 'green'], index=index)
    lw = pd.Series([1, 2, 3], index=index)
    ls = pd.Series(['solid', 'dashed', 'dashdot'], index=index)
    aa = pd.Series([True, False, True], index=index)

    Collection(edgecolors=ec)
    Collection(facecolors=fc)
    Collection(linewidths=lw)
    Collection(linestyles=ls)
    Collection(antialiaseds=aa)


@pytest.mark.style('default')
def test_lslw_bcast():
    col = mcollections.PathCollection([])
    col.set_linestyles(['-', '-'])
    col.set_linewidths([1, 2, 3])

    assert col.get_linestyles() == [(None, None)] * 6
    assert col.get_linewidths() == [1, 2, 3] * 2

    col.set_linestyles(['-', '-', '-'])
    assert col.get_linestyles() == [(None, None)] * 3
    assert (col.get_linewidths() == [1, 2, 3]).all()


@pytest.mark.style('default')
def test_capstyle():
    col = mcollections.PathCollection([], capstyle='round')
    assert col.get_capstyle() == 'round'
    col.set_capstyle('butt')
    assert col.get_capstyle() == 'butt'


@pytest.mark.style('default')
def test_joinstyle():
    col = mcollections.PathCollection([], joinstyle='round')
    assert col.get_joinstyle() == 'round'
    col.set_joinstyle('miter')
    assert col.get_joinstyle() == 'miter'


@image_comparison(['cap_and_joinstyle.png'])
def test_cap_and_joinstyle_image():
    fig = plt.figure()
    ax = fig.add_subplot(1, 1, 1)
    ax.set_xlim([-0.5, 1.5])
    ax.set_ylim([-0.5, 2.5])

    x = np.array([0.0, 1.0, 0.5])
    ys = np.array([[0.0], [0.5], [1.0]]) + np.array([[0.0, 0.0, 1.0]])

    segs = np.zeros((3, 3, 2))
    segs[:, :, 0] = x
    segs[:, :, 1] = ys
    line_segments = LineCollection(segs, linewidth=[10, 15, 20])
    line_segments.set_capstyle("round")
    line_segments.set_joinstyle("miter")

    ax.add_collection(line_segments)
    ax.set_title('Line collection with customized caps and joinstyle')


@image_comparison(['scatter_post_alpha.png'],
                  remove_text=True, style='default')
def test_scatter_post_alpha():
    fig, ax = plt.subplots()
    sc = ax.scatter(range(5), range(5), c=range(5))
    # this needs to be here to update internal state
    fig.canvas.draw()
    sc.set_alpha(.1)


def test_pathcollection_legend_elements():
    np.random.seed(19680801)
    x, y = np.random.rand(2, 10)
    y = np.random.rand(10)
    c = np.random.randint(0, 5, size=10)
    s = np.random.randint(10, 300, size=10)

    fig, ax = plt.subplots()
    sc = ax.scatter(x, y, c=c, s=s, cmap="jet", marker="o", linewidths=0)

    h, l = sc.legend_elements(fmt="{x:g}")
    assert len(h) == 5
    assert_array_equal(np.array(l).astype(float), np.arange(5))
    colors = np.array([line.get_color() for line in h])
    colors2 = sc.cmap(np.arange(5)/4)
    assert_array_equal(colors, colors2)
    l1 = ax.legend(h, l, loc=1)

    h2, lab2 = sc.legend_elements(num=9)
    assert len(h2) == 9
    l2 = ax.legend(h2, lab2, loc=2)

    h, l = sc.legend_elements(prop="sizes", alpha=0.5, color="red")
    alpha = np.array([line.get_alpha() for line in h])
    assert_array_equal(alpha, 0.5)
    color = np.array([line.get_markerfacecolor() for line in h])
    assert_array_equal(color, "red")
    l3 = ax.legend(h, l, loc=4)

    h, l = sc.legend_elements(prop="sizes", num=4, fmt="{x:.2f}",
                              func=lambda x: 2*x)
    actsizes = [line.get_markersize() for line in h]
    labeledsizes = np.sqrt(np.array(l).astype(float)/2)
    assert_array_almost_equal(actsizes, labeledsizes)
    l4 = ax.legend(h, l, loc=3)

    import matplotlib.ticker as mticker
    loc = mticker.MaxNLocator(nbins=9, min_n_ticks=9-1,
                              steps=[1, 2, 2.5, 3, 5, 6, 8, 10])
    h5, lab5 = sc.legend_elements(num=loc)
    assert len(h2) == len(h5)

    levels = [-1, 0, 55.4, 260]
    h6, lab6 = sc.legend_elements(num=levels, prop="sizes", fmt="{x:g}")
    assert_array_equal(np.array(lab6).astype(float), levels[2:])

    for l in [l1, l2, l3, l4]:
        ax.add_artist(l)

    fig.canvas.draw()


def test_EventCollection_nosort():
    # Check that EventCollection doesn't modify input in place
    arr = np.array([3, 2, 1, 10])
    coll = EventCollection(arr)
    np.testing.assert_array_equal(arr, np.array([3, 2, 1, 10]))