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

.. _gallery_scatter_with_layered_histogram:


Interactive Scatter Plot and Linked Layered Histogram
=====================================================

This example shows how to link a scatter plot and a histogram
together such that clicking on a point in the scatter plot will
isolate the distribution corresponding to that point, and vice versa.


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

    

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

    # generate fake data
    source = pd.DataFrame({'gender': ['M']*1000 + ['F']*1000,
                   'height':np.concatenate((np.random.normal(69, 7, 1000),
                                           np.random.normal(64, 6, 1000))),
                   'weight': np.concatenate((np.random.normal(195.8, 144, 1000),
                                            np.random.normal(167, 100, 1000))),
                   'age': np.concatenate((np.random.normal(45, 8, 1000),
                                            np.random.normal(51, 6, 1000)))
            })

    selector = alt.selection_single(empty='all', fields=['gender'])

    color_scale = alt.Scale(domain=['M', 'F'],
                            range=['#1FC3AA', '#8624F5'])

    base = alt.Chart(source).properties(
        width=250,
        height=250
    ).add_selection(selector)

    points = base.mark_point(filled=True, size=200).encode(
        x=alt.X('mean(height):Q',
                scale=alt.Scale(domain=[0,84])),
        y=alt.Y('mean(weight):Q',
                scale=alt.Scale(domain=[0,250])),
        color=alt.condition(selector,
                            'gender:N',
                            alt.value('lightgray'),
                            scale=color_scale),
    )

    hists = base.mark_bar(opacity=0.5, thickness=100).encode(
        x=alt.X('age',
                bin=alt.Bin(step=5), # step keeps bin size the same
                scale=alt.Scale(domain=[0,100])),
        y=alt.Y('count()',
                stack=None,
                scale=alt.Scale(domain=[0,350])),
        color=alt.Color('gender:N',
                        scale=color_scale)
    ).transform_filter(
        selector
    )


    points | hists


.. toctree::
   :hidden: