Altair Renderer and Data Transformer

VegaFusion Renderer

As an alternative to using the VegaFusionWidget directly, VegaFusion provides a custom Altair renderer. This uses the a VegaFusionWidget for display, but it doesn’t require the explicit construction of a VegaFusionWidget instance.

VegaFusion Data Transformer

VegaFusion also provides a custom data transformer. When an Altair chart is created based on a pandas DataFrame, the VegaFusion transformer will extract the DataFrame and save it to a feather file in the _vegafusion_data directory in the current directory. The feather file’s name is generated based on a hash of the DataFrame’s contents, so new files will only be added to the directory when charts are created with new DataFrames. Feel free to delete the directory when no interactive VegaFusion charts are currently being displayed, but deleting the directory while an interactive chart is being displayed may result in an error.

Activating Renderer and Data Transformer

The VegaFusion renderer and data transformer can both be activated using the enable function from the vegafusion-jupyter package.

import vegafusion as vf

After calling enable, subsequent Altair charts will automatically be rendered using VegaFusion.

import altair as alt
from vega_datasets import data

source = data.movies.url

    alt.X("IMDB_Rating:Q", bin=True),