Bump Chart

A bump chart shows how the rank of each series changes across discrete time points or conditions. Lines connect consecutive ranks; the best rank (1) appears at the top.

Basic usage (pre-ranked)

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

let plot = BumpPlot::new()
    .with_series("Alpha", vec![1, 3, 2, 1])
    .with_series("Beta",  vec![2, 1, 1, 3])
    .with_series("Gamma", vec![3, 2, 3, 2])
    .with_x_labels(["2021", "2022", "2023", "2024"]);

let plots = vec![Plot::Bump(plot)];
let layout = Layout::auto_from_plots(&plots).with_title("Rank over time");
let svg = SvgBackend.render_scene(&render_multiple(plots, layout));
std::fs::write("bump.svg", svg).unwrap();
}

Auto-ranking from raw values

Instead of supplying pre-computed ranks you can provide raw values; kuva ranks them per time point automatically.

#![allow(unused)]
fn main() {
use kuva::plot::bump::BumpPlot;

let plot = BumpPlot::new()
    .with_raw_series("A", vec![95.0, 80.0, 88.0])
    .with_raw_series("B", vec![80.0, 95.0, 72.0])
    .with_raw_series("C", vec![70.0, 85.0, 95.0])
    .with_x_labels(["Q1", "Q2", "Q3"]);
}

By default, higher value = rank 1 (better). Pass .with_rank_ascending(true) to flip this so lower value = rank 1.

Builder reference

Method	Default	Description
`.with_series(name, ranks)`	—	Add a pre-ranked series (integer or float ranks).
`.with_ranked_series(name, ranks)`	—	Pre-ranked series that allows `None` gaps.
`.with_raw_series(name, values)`	—	Raw values; ranks computed automatically.
`.with_raw_series_opt(name, values)`	—	Raw values with optional gaps (`None` breaks the line).
`.with_x_labels(labels)`	—	Labels for each time point / condition on the x-axis.
`.with_curve_style(style)`	`Sigmoid`	Line style between rank points: `Sigmoid` or `Straight`.
`.with_show_rank_labels(bool)`	`false`	Draw the rank number inside each dot.
`.with_show_series_labels(bool)`	`true`	Draw series name labels at the left and right edges.
`.with_dot_radius(f64)`	`6.0`	Dot radius in pixels.
`.with_stroke_width(f64)`	`2.5`	Line stroke width in pixels.
`.with_highlight(name)`	`None`	Highlight one series; all others are muted to 20 % opacity.
`.with_legend(bool)`	`true`	Show / hide the legend.
`.with_rank_ascending(bool)`	`false`	If `true`, lower raw value → better (lower) rank number.
`.with_tie_break(mode)`	`Average`	Tie-breaking for auto-ranking: `Average`, `Min`, `Max`, `Stable`.

Highlight mode

Highlighting one series draws it with a thicker stroke and bolder endpoint labels; all others are rendered at reduced opacity and with muted grey labels.

#![allow(unused)]
fn main() {
let plot = BumpPlot::new()
    .with_series("Alpha", vec![1, 3, 2, 1])
    .with_series("Beta",  vec![2, 1, 1, 3])
    .with_series("Gamma", vec![3, 2, 3, 2])
    .with_highlight("Alpha");
}

Missing time points

Supply None entries via .with_ranked_series or .with_raw_series_opt to produce line breaks at absent time points:

#![allow(unused)]
fn main() {
let plot = BumpPlot::new()
    .with_ranked_series("Alpha", vec![Some(1.0), None, Some(2.0), Some(1.0)])
    .with_x_labels(["A", "B", "C", "D"]);
}

Tie-breaking modes

Mode	Behavior
`Average` (default)	Tied series share the average of the occupied rank positions (e.g. 2.5, 2.5).
`Min`	All tied series receive the best (minimum) rank number.
`Max`	All tied series receive the worst (maximum) rank number.
`Stable`	Tied series retain their insertion order.