.. This document is auto-generated by the altair-gallery extension. Do not modify directly.

.. _gallery_simple_heatmap:


Simple Heatmap
--------------
This example shows a simple heatmap for showing gridded data.


.. altair-plot::
    :code-below:

    
    import altair as alt
    import numpy as np
    import pandas as pd

    # Compute x^2 + y^2 across a 2D grid
    x, y = np.meshgrid(range(-5, 5), range(-5, 5))
    z = x ** 2 + y ** 2

    # Convert this grid to columnar data expected by Altair
    source = pd.DataFrame({'x': x.ravel(),
                         'y': y.ravel(),
                         'z': z.ravel()})

    alt.Chart(source).mark_rect().encode(
        x='x:O',
        y='y:O',
        color='z:Q'
    )


.. toctree::
   :hidden: