.. 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_specialty_plots_hinton_demo.py:
===============
Hinton diagrams
===============
Hinton diagrams are useful for visualizing the values of a 2D array (e.g.
a weight matrix): Positive and negative values are represented by white and
black squares, respectively, and the size of each square represents the
magnitude of each value.
Initial idea from David Warde-Farley on the SciPy Cookbook
.. image:: /gallery/specialty_plots/images/sphx_glr_hinton_demo_001.png
:alt: hinton demo
:class: sphx-glr-single-img
.. code-block:: default
import numpy as np
import matplotlib.pyplot as plt
def hinton(matrix, max_weight=None, ax=None):
"""Draw Hinton diagram for visualizing a weight matrix."""
ax = ax if ax is not None else plt.gca()
if not max_weight:
max_weight = 2 ** np.ceil(np.log(np.abs(matrix).max()) / np.log(2))
ax.patch.set_facecolor('gray')
ax.set_aspect('equal', 'box')
ax.xaxis.set_major_locator(plt.NullLocator())
ax.yaxis.set_major_locator(plt.NullLocator())
for (x, y), w in np.ndenumerate(matrix):
color = 'white' if w > 0 else 'black'
size = np.sqrt(np.abs(w) / max_weight)
rect = plt.Rectangle([x - size / 2, y - size / 2], size, size,
facecolor=color, edgecolor=color)
ax.add_patch(rect)
ax.autoscale_view()
ax.invert_yaxis()
if __name__ == '__main__':
# Fixing random state for reproducibility
np.random.seed(19680801)
hinton(np.random.rand(20, 20) - 0.5)
plt.show()
.. _sphx_glr_download_gallery_specialty_plots_hinton_demo.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: hinton_demo.py `
.. container:: sphx-glr-download sphx-glr-download-jupyter
:download:`Download Jupyter notebook: hinton_demo.ipynb `
.. only:: html
.. rst-class:: sphx-glr-signature
Keywords: matplotlib code example, codex, python plot, pyplot
`Gallery generated by Sphinx-Gallery
`_