A Sankey diagram displays directed flows between nodes arranged in vertical columns. Nodes are rendered as rectangles; tapered ribbons connect them, with ribbon width proportional to flow magnitude.
Constructor
new
Create a Sankey plot with default settings.
use kuva::plot::SankeyPlot;
let sankey = SankeyPlot::new();
SankeyPlot
Defaults:
- Link color: source node color
- Link opacity: 0.5
- Node width: 20.0 pixels
- Node gap: 8.0 pixels
- No legend
Node Methods
with_node
Declare a node explicitly (no-op if it already exists).
pub fn with_node<S: Into<String>>(self, label: S) -> Self
let sankey = SankeyPlot::new()
.with_node("Source")
.with_node("Target");
with_node_color
Set the color for a node, creating it if absent.
pub fn with_node_color<S: Into<String>, C: Into<String>>(self, label: S, color: C) -> Self
let sankey = SankeyPlot::new()
.with_node_color("Source", "steelblue")
.with_node_color("Target", "firebrick");
with_node_column
Pin a node to a specific column, creating it if absent.
pub fn with_node_column<S: Into<String>>(self, label: S, col: usize) -> Self
Column index (0 = leftmost)
let sankey = SankeyPlot::new()
.with_node_column("Source", 0)
.with_node_column("Middle", 1)
.with_node_column("Target", 2);
Link Methods
with_link
Add a link, auto-creating nodes by label if needed.
pub fn with_link<S: Into<String>>(self, source: S, target: S, value: f64) -> Self
let sankey = SankeyPlot::new()
.with_link("A", "B", 120.0)
.with_link("A", "C", 80.0)
.with_link("B", "D", 50.0);
with_link_colored
Add a link with an explicit per-link color.
pub fn with_link_colored<S: Into<String>, C: Into<String>>(
self, source: S, target: S, value: f64, color: C,
) -> Self
CSS color string for this link
with_links
Bulk add links from an iterator of (source_label, target_label, value).
pub fn with_links<S, I>(self, links: I) -> Self
where
S: Into<String>,
I: IntoIterator<Item = (S, S, f64)>,
links
impl IntoIterator<Item = (String, String, f64)>
Iterator of (source, target, value) triplets
let links = vec![
("A", "B", 120.0),
("A", "C", 80.0),
("B", "D", 50.0),
];
let sankey = SankeyPlot::new().with_links(links);
Link Color Configuration
with_gradient_links
Use gradient ribbons (linearGradient from source to target color).
pub fn with_gradient_links(self) -> Self
let sankey = SankeyPlot::new()
.with_links(links)
.with_gradient_links();
with_per_link_colors
Use per-link colors (falls back to source color if link.color is None).
pub fn with_per_link_colors(self) -> Self
Layout Configuration
with_link_opacity
Set the ribbon fill opacity.
pub fn with_link_opacity(self, opacity: f64) -> Self
Opacity from 0.0 to 1.0 (default: 0.5)
with_node_width
Set the node rectangle width in pixels.
pub fn with_node_width(self, width: f64) -> Self
Node width in pixels (default: 20.0)
with_node_gap
Set the minimum gap between nodes in a column in pixels.
pub fn with_node_gap(self, gap: f64) -> Self
Gap in pixels (default: 8.0)
Legend
with_legend
Enable a node legend.
pub fn with_legend<S: Into<String>>(self, label: S) -> Self
Full Example
use kuva::plot::SankeyPlot;
use kuva::backend::svg::SvgBackend;
use kuva::render::render::render_multiple;
use kuva::render::layout::Layout;
use kuva::render::plots::Plot;
let sankey = SankeyPlot::new()
.with_node_color("Raw", "steelblue")
.with_node_color("QC Pass", "seagreen")
.with_node_color("QC Fail", "firebrick")
.with_node_color("Mapped", "goldenrod")
.with_link("Raw", "QC Pass", 850.0)
.with_link("Raw", "QC Fail", 150.0)
.with_link("QC Pass", "Mapped", 800.0)
.with_legend("Pipeline stages");
let plots = vec![Plot::Sankey(sankey)];
let layout = Layout::auto_from_plots(&plots)
.with_title("Sequencing Pipeline Flow");
let svg = SvgBackend.render_scene(&render_multiple(plots, layout));
std::fs::write("sankey.svg", svg).unwrap();