.. note:: :class: sphx-glr-download-link-note Click :ref:`here ` to download the full example code .. rst-class:: sphx-glr-example-title .. _sphx_glr_gallery_statistics_errorbar_features.py: ======================================= Different ways of specifying error bars ======================================= Errors can be specified as a constant value (as shown in `errorbar_demo.py`). However, this example demonstrates how they vary by specifying arrays of error values. If the raw ``x`` and ``y`` data have length N, there are two options: Array of shape (N,): Error varies for each point, but the error values are symmetric (i.e. the lower and upper values are equal). Array of shape (2, N): Error varies for each point, and the lower and upper limits (in that order) are different (asymmetric case) In addition, this example demonstrates how to use log scale with error bars. .. image:: /gallery/statistics/images/sphx_glr_errorbar_features_001.png :class: sphx-glr-single-img .. code-block:: default import numpy as np import matplotlib.pyplot as plt # example data x = np.arange(0.1, 4, 0.5) y = np.exp(-x) # example error bar values that vary with x-position error = 0.1 + 0.2 * x fig, (ax0, ax1) = plt.subplots(nrows=2, sharex=True) ax0.errorbar(x, y, yerr=error, fmt='-o') ax0.set_title('variable, symmetric error') # error bar values w/ different -/+ errors that # also vary with the x-position lower_error = 0.4 * error upper_error = error asymmetric_error = [lower_error, upper_error] ax1.errorbar(x, y, xerr=asymmetric_error, fmt='o') ax1.set_title('variable, asymmetric error') ax1.set_yscale('log') plt.show() .. _sphx_glr_download_gallery_statistics_errorbar_features.py: .. only :: html .. container:: sphx-glr-footer :class: sphx-glr-footer-example .. container:: sphx-glr-download :download:`Download Python source code: errorbar_features.py ` .. container:: sphx-glr-download :download:`Download Jupyter notebook: errorbar_features.ipynb ` .. only:: html .. rst-class:: sphx-glr-signature Keywords: matplotlib code example, codex, python plot, pyplot `Gallery generated by Sphinx-Gallery `_