Enum Arrangement 

pub enum Arrangement {
    Snap,
    Perpendicular,
    Freeform,
    Fixed,
}

An enumeration representing node arrangement strategies for Sankey diagrams.

The Arrangement enum controls how nodes are positioned relative to each other:

• Snap — If value is snap (the default), the node arrangement is assisted by automatic snapping of elements to preserve space between nodes specified via nodepad.
• Perpendicular — Nodes can only move along a line perpendicular to the primary flow.
• Freeform — Nodes can freely move anywhere on the plane without automatic constraints.
• Fixed — Nodes remain stationary at their specified positions and are not adjusted by the layout algorithm.

Example

use plotlars::{Arrangement, SankeyDiagram, Orientation, Plot, Rgb, Text};
use polars::prelude::*;

let dataset = df![
    "source" => &["A1", "A2", "A1", "B1", "B2", "B2"],
    "target" => &["B1", "B2", "B2", "C1", "C1", "C2"],
    "value"  => &[8, 4, 2, 8, 4, 2],
].unwrap();

SankeyDiagram::builder()
    .data(&dataset)
    .sources("source")
    .targets("target")
    .values("value")
    .orientation(Orientation::Horizontal)
    .arrangement(Arrangement::Freeform)
    .node_colors(vec![
        Rgb(222, 235, 247),
        Rgb(198, 219, 239),
        Rgb(158, 202, 225),
        Rgb(107, 174, 214),
        Rgb( 66, 146, 198),
        Rgb( 33, 113, 181),
    ])
    .link_colors(vec![
        Rgb(222, 235, 247),
        Rgb(198, 219, 239),
        Rgb(158, 202, 225),
        Rgb(107, 174, 214),
        Rgb( 66, 146, 198),
        Rgb( 33, 113, 181),
    ])
    .build()
    .plot();

Variants

Snap

Perpendicular

Freeform

Fixed