.. _pylab_examples-errorbar_demo: pylab_examples example code: errorbar_demo.py ============================================= .. plot:: /home/mdboom/Work/builds/matplotlib/doc/mpl_examples/pylab_examples/errorbar_demo.py :: #!/usr/bin/env python import numpy as np import matplotlib.pyplot as plt # example data x = np.arange(0.1, 4, 0.5) y = np.exp(-x) # example variable error bar values yerr = 0.1 + 0.2*np.sqrt(x) xerr = 0.1 + yerr # First illustrate basic pyplot interface, using defaults where possible. plt.figure() plt.errorbar(x, y, xerr=0.2, yerr=0.4) plt.title("Simplest errorbars, 0.2 in x, 0.4 in y") # Now switch to a more OO interface to exercise more features. fig, axs = plt.subplots(nrows=2, ncols=2, sharex=True) ax = axs[0,0] ax.errorbar(x, y, yerr=yerr, fmt='o') ax.set_title('Vert. symmetric') # With 4 subplots, reduce the number of axis ticks to avoid crowding. ax.locator_params(nbins=4) ax = axs[0,1] ax.errorbar(x, y, xerr=xerr, fmt='o') ax.set_title('Hor. symmetric') ax = axs[1,0] ax.errorbar(x, y, yerr=[yerr, 2*yerr], xerr=[xerr, 2*xerr], fmt='--o') ax.set_title('H, V asymmetric') ax = axs[1,1] ax.set_yscale('log') # Here we have to be careful to keep all y values positive: ylower = np.maximum(1e-2, y - yerr) yerr_lower = y - ylower ax.errorbar(x, y, yerr=[yerr_lower, 2*yerr], xerr=xerr, fmt='o', ecolor='g', capthick=2) ax.set_title('Mixed sym., log y') fig.suptitle('Variable errorbars') plt.show() Keywords: python, matplotlib, pylab, example, codex (see :ref:`how-to-search-examples`)