matplotlib · patniharshit · Feb 26, 2017 · QuLogic · Feb 26, 2017 · QuLogic
diff --git a/examples/images_contours_and_fields/streamplot_demo_features.py b/examples/images_contours_and_fields/streamplot_demo_features.py
@@ -31,3 +31,56 @@
 ax2.streamplot(X, Y, U, V, density=0.6, color='k', linewidth=lw)
 
 plt.show()
+
+"""
+================================
+Streamplot function with masking
+================================
+
+This example shows how streamlines created by the streamplot function skips
+masked regions and NaN values.
+"""
+w = 3
+Y, X = np.mgrid[-w:w:100j, -w:w:100j]
+U = -1 - X**2 + Y
+V = 1 + X - Y**2
+speed = np.sqrt(U*U + V*V)
+
+mask = np.zeros(U.shape, dtype=bool)
+mask[40:60, 40:60] = True
+U[:20, :20] = np.nan
+U = np.ma.array(U, mask=mask)
+
+fig, ax = plt.subplots()
+ax.streamplot(X, Y, U, V, color='r')
+
+ax.imshow(~mask, extent=(-w, w, -w, w), alpha=0.5,
+          interpolation='nearest', cmap=plt.cm.gray)
+
+plt.show()
+
+"""
+========================================
+Streamplot function with starting points
+========================================
+
+This example shows how to fix the streamlines that are plotted, by passing
+an array of seed points to the `start_points` keyword argument.
+"""
+Y, X = np.mgrid[-3:3:100j, -3:3:100j]
+U = -1 - X**2 + Y
+V = 1 + X - Y**2
+
+# 5 points along the first diagonal and a point in the left upper quadrant
+seed_points = np.array([[-2, -1, 0, 1, 2, -1], [-2, -1,  0, 1, 2, 2]])
+
+fig, ax = plt.subplots()
+strm = ax.streamplot(X, Y, U, V, color=U, linewidth=2,
+                     cmap=plt.cm.autumn, start_points=seed_points.T)
+fig.colorbar(strm.lines)
+
+ax.plot(seed_points[0], seed_points[1], 'bo')
+
+ax.axis((-3, 3, -3, 3))
+
+plt.show()
diff --git a/examples/images_contours_and_fields/streamplot_demo_masking.py b/examples/images_contours_and_fields/streamplot_demo_masking.py
diff --git a/examples/images_contours_and_fields/streamplot_demo_start_points.py b/examples/images_contours_and_fields/streamplot_demo_start_points.py