@woosh/meep-engine/src/core/graph/graph_compute_degree_matrix.js

Pure JavaScript game engine. Fully featured and production ready.

import { assert } from "../assert.js";

/**
 * Builds a matrix with node cardinality for each Node, that is, number of edges attached to each Node
 * NOTE: does not clear matrix before writing
 * @template T
 * @param {Graph<T>} graph
 * @param {SquareMatrix} result Where to store the result
 * @param {Map<T,number>} node_indices de-referencing dictionary from Node to unsigned integer index
 */
export function graph_compute_degree_matrix(graph, result, node_indices) {
    const nodes = graph.getNodes();

    for (const node of nodes) {
        const node_index = node_indices.get(node);

        assert.isNonNegativeInteger(node_index, 'index');

        const degree = graph.getNodeDegree(node);

        result.setCellValue(node_index, node_index, degree);
    }
}