import platform import sys import numpy as np import pytest from matplotlib import pyplot as plt from matplotlib.testing.decorators import image_comparison def draw_quiver(ax, **kw): X, Y = np.meshgrid(np.arange(0, 2 * np.pi, 1), np.arange(0, 2 * np.pi, 1)) U = np.cos(X) V = np.sin(Y) Q = ax.quiver(U, V, **kw) return Q @pytest.mark.skipif(platform.python_implementation() != 'CPython', reason='Requires CPython') def test_quiver_memory_leak(): fig, ax = plt.subplots() Q = draw_quiver(ax) ttX = Q.X Q.remove() del Q assert sys.getrefcount(ttX) == 2 @pytest.mark.skipif(platform.python_implementation() != 'CPython', reason='Requires CPython') def test_quiver_key_memory_leak(): fig, ax = plt.subplots() Q = draw_quiver(ax) qk = ax.quiverkey(Q, 0.5, 0.92, 2, r'$2 \frac{m}{s}$', labelpos='W', fontproperties={'weight': 'bold'}) assert sys.getrefcount(qk) == 3 qk.remove() assert sys.getrefcount(qk) == 2 def test_quiver_number_of_args(): X = [1, 2] with pytest.raises( TypeError, match='takes 2-5 positional arguments but 1 were given'): plt.quiver(X) with pytest.raises( TypeError, match='takes 2-5 positional arguments but 6 were given'): plt.quiver(X, X, X, X, X, X) def test_quiver_arg_sizes(): X2 = [1, 2] X3 = [1, 2, 3] with pytest.raises( ValueError, match=('X and Y must be the same size, but ' 'X.size is 2 and Y.size is 3.')): plt.quiver(X2, X3, X2, X2) with pytest.raises( ValueError, match=('Argument U has a size 3 which does not match ' '2, the number of arrow positions')): plt.quiver(X2, X2, X3, X2) with pytest.raises( ValueError, match=('Argument V has a size 3 which does not match ' '2, the number of arrow positions')): plt.quiver(X2, X2, X2, X3) with pytest.raises( ValueError, match=('Argument C has a size 3 which does not match ' '2, the number of arrow positions')): plt.quiver(X2, X2, X2, X2, X3) def test_no_warnings(): fig, ax = plt.subplots() X, Y = np.meshgrid(np.arange(15), np.arange(10)) U = V = np.ones_like(X) phi = (np.random.rand(15, 10) - .5) * 150 ax.quiver(X, Y, U, V, angles=phi) fig.canvas.draw() # Check that no warning is emitted. def test_zero_headlength(): # Based on report by Doug McNeil: # http://matplotlib.1069221.n5.nabble.com/quiver-warnings-td28107.html fig, ax = plt.subplots() X, Y = np.meshgrid(np.arange(10), np.arange(10)) U, V = np.cos(X), np.sin(Y) ax.quiver(U, V, headlength=0, headaxislength=0) fig.canvas.draw() # Check that no warning is emitted. @image_comparison(['quiver_animated_test_image.png']) def test_quiver_animate(): # Tests fix for #2616 fig, ax = plt.subplots() Q = draw_quiver(ax, animated=True) ax.quiverkey(Q, 0.5, 0.92, 2, r'$2 \frac{m}{s}$', labelpos='W', fontproperties={'weight': 'bold'}) @image_comparison(['quiver_with_key_test_image.png']) def test_quiver_with_key(): fig, ax = plt.subplots() ax.margins(0.1) Q = draw_quiver(ax) ax.quiverkey(Q, 0.5, 0.95, 2, r'$2\, \mathrm{m}\, \mathrm{s}^{-1}$', angle=-10, coordinates='figure', labelpos='W', fontproperties={'weight': 'bold', 'size': 'large'}) @image_comparison(['quiver_single_test_image.png'], remove_text=True) def test_quiver_single(): fig, ax = plt.subplots() ax.margins(0.1) ax.quiver([1], [1], [2], [2]) def test_quiver_copy(): fig, ax = plt.subplots() uv = dict(u=np.array([1.1]), v=np.array([2.0])) q0 = ax.quiver([1], [1], uv['u'], uv['v']) uv['v'][0] = 0 assert q0.V[0] == 2.0 @image_comparison(['quiver_key_pivot.png'], remove_text=True) def test_quiver_key_pivot(): fig, ax = plt.subplots() u, v = np.mgrid[0:2*np.pi:10j, 0:2*np.pi:10j] q = ax.quiver(np.sin(u), np.cos(v)) ax.set_xlim(-2, 11) ax.set_ylim(-2, 11) ax.quiverkey(q, 0.5, 1, 1, 'N', labelpos='N') ax.quiverkey(q, 1, 0.5, 1, 'E', labelpos='E') ax.quiverkey(q, 0.5, 0, 1, 'S', labelpos='S') ax.quiverkey(q, 0, 0.5, 1, 'W', labelpos='W') @image_comparison(['quiver_key_xy.png'], remove_text=True) def test_quiver_key_xy(): # With scale_units='xy', ensure quiverkey still matches its quiver. # Note that the quiver and quiverkey lengths depend on the axes aspect # ratio, and that with angles='xy' their angles also depend on the axes # aspect ratio. X = np.arange(8) Y = np.zeros(8) angles = X * (np.pi / 4) uv = np.exp(1j * angles) U = uv.real V = uv.imag fig, axs = plt.subplots(2) for ax, angle_str in zip(axs, ('uv', 'xy')): ax.set_xlim(-1, 8) ax.set_ylim(-0.2, 0.2) q = ax.quiver(X, Y, U, V, pivot='middle', units='xy', width=0.05, scale=2, scale_units='xy', angles=angle_str) for x, angle in zip((0.2, 0.5, 0.8), (0, 45, 90)): ax.quiverkey(q, X=x, Y=0.8, U=1, angle=angle, label='', color='b') @image_comparison(['barbs_test_image.png'], remove_text=True) def test_barbs(): x = np.linspace(-5, 5, 5) X, Y = np.meshgrid(x, x) U, V = 12*X, 12*Y fig, ax = plt.subplots() ax.barbs(X, Y, U, V, np.hypot(U, V), fill_empty=True, rounding=False, sizes=dict(emptybarb=0.25, spacing=0.2, height=0.3), cmap='viridis') @image_comparison(['barbs_pivot_test_image.png'], remove_text=True) def test_barbs_pivot(): x = np.linspace(-5, 5, 5) X, Y = np.meshgrid(x, x) U, V = 12*X, 12*Y fig, ax = plt.subplots() ax.barbs(X, Y, U, V, fill_empty=True, rounding=False, pivot=1.7, sizes=dict(emptybarb=0.25, spacing=0.2, height=0.3)) ax.scatter(X, Y, s=49, c='black') @image_comparison(['barbs_test_flip.png'], remove_text=True) def test_barbs_flip(): """Test barbs with an array for flip_barb.""" x = np.linspace(-5, 5, 5) X, Y = np.meshgrid(x, x) U, V = 12*X, 12*Y fig, ax = plt.subplots() ax.barbs(X, Y, U, V, fill_empty=True, rounding=False, pivot=1.7, sizes=dict(emptybarb=0.25, spacing=0.2, height=0.3), flip_barb=Y < 0) def test_barb_copy(): fig, ax = plt.subplots() u = np.array([1.1]) v = np.array([2.2]) b0 = ax.barbs([1], [1], u, v) u[0] = 0 assert b0.u[0] == 1.1 v[0] = 0 assert b0.v[0] == 2.2 def test_bad_masked_sizes(): """Test error handling when given differing sized masked arrays.""" x = np.arange(3) y = np.arange(3) u = np.ma.array(15. * np.ones((4,))) v = np.ma.array(15. * np.ones_like(u)) u[1] = np.ma.masked v[1] = np.ma.masked fig, ax = plt.subplots() with pytest.raises(ValueError): ax.barbs(x, y, u, v) def test_angles_and_scale(): # angles array + scale_units kwarg fig, ax = plt.subplots() X, Y = np.meshgrid(np.arange(15), np.arange(10)) U = V = np.ones_like(X) phi = (np.random.rand(15, 10) - .5) * 150 ax.quiver(X, Y, U, V, angles=phi, scale_units='xy') @image_comparison(['quiver_xy.png'], remove_text=True) def test_quiver_xy(): # simple arrow pointing from SW to NE fig, ax = plt.subplots(subplot_kw=dict(aspect='equal')) ax.quiver(0, 0, 1, 1, angles='xy', scale_units='xy', scale=1) ax.set_xlim(0, 1.1) ax.set_ylim(0, 1.1) ax.grid() def test_quiverkey_angles(): # Check that only a single arrow is plotted for a quiverkey when an array # of angles is given to the original quiver plot fig, ax = plt.subplots() X, Y = np.meshgrid(np.arange(2), np.arange(2)) U = V = angles = np.ones_like(X) q = ax.quiver(X, Y, U, V, angles=angles) qk = ax.quiverkey(q, 1, 1, 2, 'Label') # The arrows are only created when the key is drawn fig.canvas.draw() assert len(qk.verts) == 1 def test_quiver_setuvc_numbers(): """Check that it is possible to set all arrow UVC to the same numbers""" fig, ax = plt.subplots() X, Y = np.meshgrid(np.arange(2), np.arange(2)) U = V = np.ones_like(X) q = ax.quiver(X, Y, U, V) q.set_UVC(0, 1)