

.. _sphx_glr_gallery_pylab_examples_log_demo.py:


========
Log Demo
========





.. image:: /gallery/pylab_examples/images/sphx_glr_log_demo_001.png
    :align: center





.. code-block:: python


    import numpy as np
    import matplotlib.pyplot as plt

    plt.subplots_adjust(hspace=0.4)
    t = np.arange(0.01, 20.0, 0.01)

    # log y axis
    plt.subplot(221)
    plt.semilogy(t, np.exp(-t/5.0))
    plt.title('semilogy')
    plt.grid(True)

    # log x axis
    plt.subplot(222)
    plt.semilogx(t, np.sin(2*np.pi*t))
    plt.title('semilogx')
    plt.grid(True)

    # log x and y axis
    plt.subplot(223)
    plt.loglog(t, 20*np.exp(-t/10.0), basex=2)
    plt.grid(True)
    plt.title('loglog base 2 on x')

    # with errorbars: clip non-positive values
    ax = plt.subplot(224)
    ax.set_xscale("log", nonposx='clip')
    ax.set_yscale("log", nonposy='clip')

    x = 10.0**np.linspace(0.0, 2.0, 20)
    y = x**2.0
    plt.errorbar(x, y, xerr=0.1*x, yerr=5.0 + 0.75*y)
    ax.set_ylim(ymin=0.1)
    ax.set_title('Errorbars go negative')


    plt.show()

**Total running time of the script:** ( 0 minutes  0.101 seconds)



.. container:: sphx-glr-footer


  .. container:: sphx-glr-download

     :download:`Download Python source code: log_demo.py <log_demo.py>`



  .. container:: sphx-glr-download

     :download:`Download Jupyter notebook: log_demo.ipynb <log_demo.ipynb>`

.. rst-class:: sphx-glr-signature

    `Generated by Sphinx-Gallery <https://sphinx-gallery.readthedocs.io>`_
