1 unstable release

0.7.0 Apr 23, 2023

#141 in Visualization


14K SLoC

Vega-Lite V5 for Rust

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A Rust API for Vega-Lite V4 to build chart with a rusty API.

Similar to the Altair project in python, this crate build upon Vega-Lite specifications. Vega-Lite is a high-level grammar of interactive graphics. It provides a concise JSON syntax for rapidly generating visualizations to support analysis. Vega-Lite specifications can be compiled to Vega specifications. Those specifications are then parsed by Vega’s JavaScript runtime to generate both static images or interactive web-based views. This crate has a complete mapping of Vega-Lite 3.4 specification and can be found in src/schema.rs. With all the types and structs, it's possible to create your Rust Vegalite graph that will be serialize into a Vega-Lite JSON. Thanks to Showata the resulting visualization can be display in your Web-Browser or in a Rust Jupyter Notebook. It's also possible to use an existing Vega-Lite json and plug your data source seamlessly. This way you can leverage existing vizualisation and adapt it to your design.


In order to have a complete mapping of the Vega-Lite V4 specification the code for the schema was automaticlly generated. To help describe all the possible features a gallery of example is provided on github

To launch all examples

cargo install cargo-make
cargo make run-all-examples

Simple chart using ndarray generated data

let values: Array2<f64> = Array::random((100, 2), StandardNormal);

let chart = VegaliteBuilder::default()
    .title("Random points")

Simple chart using existing json definition with new data

// Use existing vega-lite json specification
let spec = r##"{
    "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
    "encoding": {
        "x": {
            "field": "data.0",
            "type": "quantitative"
        "y": {
            "field": "data.1",
            "type": "quantitative"
    "mark": "point",
    "title": "Random points"

// Use you own data to populate the chart
let values: Array2<f64> = Array::random((100, 2), StandardNormal);
let mut chart: Vegalite = serde_json::from_str(spec)?;
chart.data = values.into();

// display the chart using `showata`


name enabled by default functionnality related crate
show_vega yes can display charts in the browser or in a notebook showata
csv yes can load data from a csv csv
ndarray yes can load data from a ndarray ndarray
nalgebra no can load data from a nalgebra::Matrix nalgebra
rulinalg no can load data from a rulinalg::matrix::Matrix rulinalg
polars no can load data from a polars::prelude::DataFrame polars


Stack size

The vegalite json schema is large with lot of alternative, so the typed rust version create a large set of struct and enum (the generated source file before macro expension is 28K lines). So the size of a model in stack could be large (it's also why Box is used in the struct).

On wasm32, with the default stack size (~ 1 MB), using vegalite_5 can raise error like:

  • crash tab with SIGSEVG (on chromium based browser)
  • Uncaught (in promise) RuntimeError: memory access out of bounds or simply Uncaught (in promise) RuntimeError

The current work arround is to increase the stacksize (eg ~ 1.5 MB). For cargo based project you can add into .cargo/config file of the project:

rustflags = [
  "-C", "link-args=-z stack-size=1500000",


~190K SLoC