.. _images_contours_and_fields-streamplot_demo_start_points: images_contours_and_fields example code: streamplot_demo_start_points.py ======================================================================== .. plot:: /home/tcaswell/src/p/matplotlib/doc/mpl_examples/images_contours_and_fields/streamplot_demo_start_points.py :: """ Demo of the `streamplot` function. A streamplot, or streamline plot, is used to display 2D vector fields. This example shows a few features of the stream plot function: * Varying the color along a streamline. * Varying the density of streamlines. * Varying the line width along a stream line. """ import numpy as np import matplotlib.pyplot as plt X, Y = (np.linspace(-3, 3, 100), np.linspace(-3, 3, 100)) U, V = np.mgrid[-3:3:100j, 0:0:100j] seed_points = np.array([[-2, 0, 1], [-2, 0, 1]]) fig0, ax0 = plt.subplots() strm = ax0.streamplot(X, Y, U, V, color=U, linewidth=2, cmap=plt.cm.autumn, start_points=seed_points.T) fig0.colorbar(strm.lines) ax0.plot(seed_points[0], seed_points[1], 'bo') ax0.axis((-3, 3, -3, 3)) plt.show() Keywords: python, matplotlib, pylab, example, codex (see :ref:`how-to-search-examples`)