.. only:: html
.. 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_pyplots_axline.py:
==============
Infinite lines
==============
`~.axes.Axes.axvline` and `~.axes.Axes.axhline` draw infinite vertical /
horizontal lines, at given *x* / *y* positions. They are usually used to mark
special data values, e.g. in this example the center and limit values of the
sigmoid function.
`~.axes.Axes.axline` draws infinite straight lines in arbitrary directions.
.. code-block:: default
import numpy as np
import matplotlib.pyplot as plt
t = np.linspace(-10, 10, 100)
sig = 1 / (1 + np.exp(-t))
plt.axhline(y=0, color="black", linestyle="--")
plt.axhline(y=0.5, color="black", linestyle=":")
plt.axhline(y=1.0, color="black", linestyle="--")
plt.axvline(color="grey")
plt.axline((0, 0.5), slope=0.25, color="black", linestyle=(0, (5, 5)))
plt.plot(t, sig, linewidth=2, label=r"$\sigma(t) = \frac{1}{1 + e^{-t}}$")
plt.xlim(-10, 10)
plt.xlabel("t")
plt.legend(fontsize=14)
plt.show()
.. image:: /gallery/pyplots/images/sphx_glr_axline_001.png
:alt: axline
:class: sphx-glr-single-img
`~.axes.Axes.axline` can also be used with a ``transform`` parameter, which
applies to the point, but not to the slope. This can be useful for drawing
diagonal grid lines with a fixed slope, which stay in place when the
plot limits are moved.
.. code-block:: default
for pos in np.linspace(-2, 1, 10):
plt.axline((pos, 0), slope=0.5, color='k', transform=plt.gca().transAxes)
plt.ylim([0, 1])
plt.xlim([0, 1])
plt.show()
.. image:: /gallery/pyplots/images/sphx_glr_axline_002.png
:alt: axline
:class: sphx-glr-single-img
------------
References
""""""""""
The use of the following functions, methods, classes and modules is shown
in this example:
.. code-block:: default
import matplotlib
matplotlib.pyplot.axhline
matplotlib.pyplot.axvline
matplotlib.pyplot.axline
matplotlib.axes.Axes.axhline
matplotlib.axes.Axes.axvline
matplotlib.axes.Axes.axline
.. rst-class:: sphx-glr-script-out
Out:
.. code-block:: none
.. _sphx_glr_download_gallery_pyplots_axline.py:
.. only :: html
.. container:: sphx-glr-footer
:class: sphx-glr-footer-example
.. container:: sphx-glr-download sphx-glr-download-python
:download:`Download Python source code: axline.py `
.. container:: sphx-glr-download sphx-glr-download-jupyter
:download:`Download Jupyter notebook: axline.ipynb `
.. only:: html
.. rst-class:: sphx-glr-signature
Keywords: matplotlib code example, codex, python plot, pyplot
`Gallery generated by Sphinx-Gallery
`_