voronoi.js

// Import the d3 library
var d3 = require("d3");

// Define the circle and proportions
var center = {x: 0, y: 0};
var radius = 1;
var proportions = [0.2, 0.3, 0.5];

// Create the Voronoi diagram
var voronoi = d3.voronoi()
    .extent([[-radius, -radius], [radius, radius]]);

// Create the points for the Voronoi diagram
var points = proportions.map(function(proportion, i) {
    var angle = proportion * 2 * Math.PI;
    return [center.x + radius * Math.cos(angle), center.y + radius * Math.sin(angle)];
});

// Compute the Voronoi diagram
var diagram = voronoi(points);

// The Voronoi polygons are now in diagram.polygons()

https://graphics.uni-konstanz.de/publikationen/Balzer2005VoronoiTreemaps/index.html and https://onlinelibrary.wiley.com/doi/10.1111/j.1467-8659.2012.03078.x use these scientific papers to create pseudo code for splitting a circle into polygons of different proportions

https://www.jasondavies.com/voronoi-treemap/

https://zbryikt.github.io/voronoijs/