.. _statistics-errorbar_limits: statistics example code: errorbar_limits.py =========================================== .. plot:: /home/tcaswell/src/p/matplotlib/doc/mpl_examples/statistics/errorbar_limits.py :: """ =========================================================== Demo of how to include upper and lower limits in error bars =========================================================== In matplotlib, errors bars can have "limits". Applying limits to the error bars essentially makes the error unidirectional. Because of that, upper and lower limits can be applied in both the y- and x-directions via the ``uplims``, ``lolims``, ``xuplims``, and ``xlolims`` parameters, respectively. These parameters can be scalar or boolean arrays. For example, if ``xlolims`` is ``True``, the x-error bars will only extend from the data towards increasing values. If ``uplims`` is an array filled with ``False`` except for the 4th and 7th values, all of the y-error bars will be bidirectional, except the 4th and 7th bars, which will extend from the data towards decreasing y-values. """ import numpy as np import matplotlib.pyplot as plt # example data x = np.array([0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0]) y = np.exp(-x) xerr = 0.1 yerr = 0.2 # lower & upper limits of the error lolims = np.array([0, 0, 1, 0, 1, 0, 0, 0, 1, 0], dtype=bool) uplims = np.array([0, 1, 0, 0, 0, 1, 0, 0, 0, 1], dtype=bool) ls = 'dotted' fig, ax = plt.subplots(figsize=(7, 4)) # standard error bars ax.errorbar(x, y, xerr=xerr, yerr=yerr, linestyle=ls) # including upper limits ax.errorbar(x, y + 0.5, xerr=xerr, yerr=yerr, uplims=uplims, linestyle=ls) # including lower limits ax.errorbar(x, y + 1.0, xerr=xerr, yerr=yerr, lolims=lolims, linestyle=ls) # including upper and lower limits ax.errorbar(x, y + 1.5, xerr=xerr, yerr=yerr, lolims=lolims, uplims=uplims, marker='o', markersize=8, linestyle=ls) # Plot a series with lower and upper limits in both x & y # constant x-error with varying y-error xerr = 0.2 yerr = np.zeros(x.shape) + 0.2 yerr[[3, 6]] = 0.3 # mock up some limits by modifying previous data xlolims = lolims xuplims = uplims lolims = np.zeros(x.shape) uplims = np.zeros(x.shape) lolims[[6]] = True # only limited at this index uplims[[3]] = True # only limited at this index # do the plotting ax.errorbar(x, y + 2.1, xerr=xerr, yerr=yerr, xlolims=xlolims, xuplims=xuplims, uplims=uplims, lolims=lolims, marker='o', markersize=8, linestyle='none') # tidy up the figure ax.set_xlim((0, 5.5)) ax.set_title('Errorbar upper and lower limits') plt.show() Keywords: python, matplotlib, pylab, example, codex (see :ref:`how-to-search-examples`)