Static code analysis and corrections

utils/venv/lib/python3.6/site-packages/matplotlib/tests/test_streamplot.py

@@ -0,0 +1,104 @@
+import sys
+import platform
+
+import numpy as np
+from numpy.testing import assert_array_almost_equal
+import matplotlib.pyplot as plt
+from matplotlib.testing.decorators import image_comparison
+import matplotlib.transforms as mtransforms
+
+
+on_win = (sys.platform == 'win32')
+
+
+def velocity_field():
+    Y, X = np.mgrid[-3:3:100j, -3:3:100j]
+    U = -1 - X**2 + Y
+    V = 1 + X - Y**2
+    return X, Y, U, V
+
+
+def swirl_velocity_field():
+    x = np.linspace(-3., 3., 100)
+    y = np.linspace(-3., 3., 100)
+    X, Y = np.meshgrid(x, y)
+    a = 0.1
+    U = np.cos(a) * (-Y) - np.sin(a) * X
+    V = np.sin(a) * (-Y) + np.cos(a) * X
+    return x, y, U, V
+
+
+@image_comparison(baseline_images=['streamplot_startpoints'],
+        remove_text=True, style='mpl20')
+def test_startpoints():
+    X, Y, U, V = velocity_field()
+    start_x = np.linspace(X.min(), X.max(), 10)
+    start_y = np.linspace(Y.min(), Y.max(), 10)
+    start_points = np.column_stack([start_x, start_y])
+    plt.streamplot(X, Y, U, V, start_points=start_points)
+    plt.plot(start_x, start_y, 'ok')
+
+
+@image_comparison(baseline_images=['streamplot_colormap'],
+                  tol=.04, remove_text=True, style='mpl20')
+def test_colormap():
+    X, Y, U, V = velocity_field()
+    plt.streamplot(X, Y, U, V, color=U, density=0.6, linewidth=2,
+                   cmap=plt.cm.autumn)
+    plt.colorbar()
+
+
+@image_comparison(baseline_images=['streamplot_linewidth'],
+                  tol={'aarch64': 0.02}.get(platform.machine(), 0.0),
+                  remove_text=True, style='mpl20')
+def test_linewidth():
+    X, Y, U, V = velocity_field()
+    speed = np.sqrt(U*U + V*V)
+    lw = 5*speed/speed.max()
+    df = 25. / 30.   # Compatibility factor for old test image
+    plt.streamplot(X, Y, U, V, density=[0.5 * df, 1. * df], color='k',
+                   linewidth=lw)
+
+
+@image_comparison(baseline_images=['streamplot_masks_and_nans'],
+                  tol=0.04 if on_win else 0,
+                  remove_text=True, style='mpl20')
+def test_masks_and_nans():
+    X, Y, U, V = velocity_field()
+    mask = np.zeros(U.shape, dtype=bool)
+    mask[40:60, 40:60] = 1
+    U[:20, :20] = np.nan
+    U = np.ma.array(U, mask=mask)
+    with np.errstate(invalid='ignore'):
+        plt.streamplot(X, Y, U, V, color=U, cmap=plt.cm.Blues)
+
+
+@image_comparison(baseline_images=['streamplot_maxlength'],
+                  extensions=['png'], remove_text=True, style='mpl20')
+def test_maxlength():
+    x, y, U, V = swirl_velocity_field()
+    plt.streamplot(x, y, U, V, maxlength=10., start_points=[[0., 1.5]],
+                   linewidth=2, density=2)
+
+
+@image_comparison(baseline_images=['streamplot_direction'],
+                  extensions=['png'], remove_text=True, style='mpl20')
+def test_direction():
+    x, y, U, V = swirl_velocity_field()
+    plt.streamplot(x, y, U, V, integration_direction='backward',
+                   maxlength=1.5, start_points=[[1.5, 0.]],
+                   linewidth=2, density=2)
+
+
+def test_streamplot_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)