.. _pylab_examples-quadmesh_demo: pylab_examples example code: quadmesh_demo.py ============================================= .. plot:: /home/tcaswell/source/p/matplotlib/doc/mpl_examples/pylab_examples/quadmesh_demo.py :: """ pcolormesh uses a QuadMesh, a faster generalization of pcolor, but with some restrictions. This demo illustrates a bug in quadmesh with masked data. """ import numpy as np from matplotlib.pyplot import figure, show, savefig from matplotlib import cm, colors from numpy import ma n = 12 x = np.linspace(-1.5, 1.5, n) y = np.linspace(-1.5, 1.5, n*2) X, Y = np.meshgrid(x, y) Qx = np.cos(Y) - np.cos(X) Qz = np.sin(Y) + np.sin(X) Qx = (Qx + 1.1) Z = np.sqrt(X**2 + Y**2)/5 Z = (Z - Z.min()) / (Z.max() - Z.min()) # The color array can include masked values: Zm = ma.masked_where(np.fabs(Qz) < 0.5*np.amax(Qz), Z) fig = figure() ax = fig.add_subplot(121) ax.pcolormesh(Qx, Qz, Z, shading='gouraud') ax.set_title('Without masked values') ax = fig.add_subplot(122) # You can control the color of the masked region: # cmap = cm.RdBu # cmap.set_bad('y', 1.0) # ax.pcolormesh(Qx, Qz, Zm, cmap=cmap) # Or use the default, which is transparent: col = ax.pcolormesh(Qx, Qz, Zm, shading='gouraud') ax.set_title('With masked values') show() Keywords: python, matplotlib, pylab, example, codex (see :ref:`how-to-search-examples`)