.. 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 `_