Box Plot

A box plot (box-and-whisker plot) displays the five-number summary of one or more groups of values. Boxes show the interquartile range (Q1–Q3) with a median line; whiskers extend to the most extreme values within 1.5×IQR of the box edges (Tukey style). Individual data points can optionally be overlaid as a jittered strip or beeswarm.

Import path: kuva::plot::BoxPlot

Basic usage

Add one group per category with .with_group(label, values). Groups are rendered left-to-right in the order they are added.

#![allow(unused)]
fn main() {
use kuva::plot::BoxPlot;
use kuva::backend::svg::SvgBackend;
use kuva::render::render::render_multiple;
use kuva::render::layout::Layout;
use kuva::render::plots::Plot;

let plot = BoxPlot::new()
    .with_group("Control",     vec![4.1, 5.0, 5.3, 5.8, 6.2, 7.0, 5.5, 4.8])
    .with_group("Treatment A", vec![5.5, 6.1, 6.4, 7.2, 7.8, 8.5, 6.9, 7.0])
    .with_group("Treatment B", vec![3.2, 4.0, 4.5, 4.8, 5.1, 5.9, 4.3, 4.7])
    .with_group("Treatment C", vec![6.0, 7.2, 7.5, 8.1, 8.8, 9.5, 7.9, 8.2])
    .with_color("steelblue");

let plots = vec![Plot::Box(plot)];
let layout = Layout::auto_from_plots(&plots)
    .with_title("Box Plot")
    .with_y_label("Value");

let scene = render_multiple(plots, layout);
let svg = SvgBackend.render_scene(&scene);
std::fs::write("boxplot.svg", svg).unwrap();
}

What the box shows

Values outside the whisker range are not drawn automatically — use an overlay to show them.

Point overlays

Overlaying the raw data on top of each box makes the sample size and distribution shape immediately visible. Both modes accept an optional color and point size.

Jittered strip

.with_strip(jitter) scatters points randomly within a horizontal band. The jitter argument controls the spread width (in data-axis units; 0.2 is a reasonable starting value).

#![allow(unused)]
fn main() {
use kuva::plot::BoxPlot;
use kuva::render::plots::Plot;

let plot = BoxPlot::new()
    .with_group("Control",     vec![/* values */])
    .with_group("Treatment A", vec![/* values */])
    .with_color("steelblue")
    .with_strip(0.2)
    .with_overlay_color("rgba(0,0,0,0.4)")
    .with_overlay_size(3.0);
}

Beeswarm

.with_swarm_overlay() uses a beeswarm algorithm to spread points horizontally to avoid overlap. This gives a clearer picture of data density and is particularly useful for smaller datasets (roughly N < 200 per group).

#![allow(unused)]
fn main() {
use kuva::plot::BoxPlot;
use kuva::render::plots::Plot;

let plot = BoxPlot::new()
    .with_group("Control",     vec![/* values */])
    .with_group("Treatment A", vec![/* values */])
    .with_color("steelblue")
    .with_swarm_overlay()
    .with_overlay_color("rgba(0,0,0,0.4)")
    .with_overlay_size(3.0);
}

A semi-transparent overlay_color is recommended so the box remains visible beneath the points.

API reference