altair_chart

Make reactive charts with Altair.

Usage

import altair as alt
import marimo as mo
from vega_datasets import data

chart = (
    alt.Chart(data.cars())
    .mark_point()
    .encode(
        x="Horsepower",
        y="Miles_per_Gallon",
        color="Origin",
    )
)

chart = mo.ui.altair_chart(chart)

# View the chart and selected data as a dataframe
mo.hstack([chart, chart.value])

Signature

mo.ui.altair_chart(
    chart: altair.Chart,
    chart_selection: Literal["point"] | Literal["interval"] | bool = True,
    legend_selection: list[str] | bool = True,
    *,
    label: str = "",
    on_change: Optional[Callable[[ChartDataType], None]] = None
)

Parameters

chart · altair.Chart · required

An Altair Chart object.

chart_selection · Literal['point'] | Literal['interval'] | bool · default: "True"

Selection type: "point", "interval", or a bool. Defaults to True which will automatically detect the best selection type. This is ignored if the chart already has a point/interval selection param.

legend_selection · list[str] | bool · default: "True"

List of legend fields (columns) for which to enable selection, True to enable selection for all fields, or False to disable selection entirely. This is ignored if the chart already has a legend selection param.

label · str · default: ""

Markdown label for the element.

on_change · Optional[Callable[[ChartDataType], None]] · default: "None"

Optional callback to run when this element’s value changes.

Attributes

value · ChartDataType

A dataframe of the plot data filtered by the selections.

dataframe · ChartDataType

A dataframe of the unfiltered chart data.

selections · ChartSelection

The selection of the chart; this may be an interval along the name of an axis or a selection of points.

Methods

apply_selection

Apply the selection to a DataFrame.

This method is useful when you have a layered chart and you want to apply the selection to a DataFrame.

selected_df = chart.apply_selection(cars)

Parameters:

• df (ChartDataType): A DataFrame to apply the selection to.

Returns: ChartDataType - A DataFrame of the plot data filtered by the selections.