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

.. _gallery_simple_scatter_with_errorbars:


Simple Scatter Plot with Errorbars
----------------------------------

A simple scatter plot of a data set with errorbars.



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

    

    import altair as alt

    import numpy as np
    import pandas as pd

    # generate some data points with uncertainties
    np.random.seed(0)
    x = [1, 2, 3, 4, 5]
    y = np.random.normal(10, 0.5, size=len(x))
    yerr = 0.2

    # set up data frame
    data = pd.DataFrame({"x":x, "y":y, "yerr":yerr})

    # generate the points
    points = alt.Chart(data).mark_point(filled=True, size=50).encode(
        alt.X("x", 
              scale=alt.Scale(domain=(0,6)),
              axis=alt.Axis(title='x')
        ),
        y=alt.Y('y', 
                scale=alt.Scale(zero=False, domain=(10, 11)),
                axis=alt.Axis(title="y")),
        color=alt.value('black')
    )

    # generate the error bars
    errorbars = alt.Chart(data).mark_rule().encode(
        x=alt.X("x"),
        y="ymin:Q",
        y2="ymax:Q"
    ).transform_calculate(
        ymin="datum.y-datum.yerr",
        ymax="datum.y+datum.yerr"
    )

    points + errorbars


.. toctree::
   :hidden: