flo-poly/src/basic/expansion/e-equal.ts

A practical, root-focused JavaScript polynomial utility library.

import { eCompare as eCompare_ } from "big-float-ts";

// We *have* to do the below❗ The assignee is a getter❗ The assigned is a pure function❗ Otherwise code is too slow❗
const eCompare = eCompare_;


/**
 * Returns true if two polynomials (with coefficients given as Shewchuk floating 
 * point expansions) are exactly equal by comparing coefficients, false otherwise.
 * 
 * @param p1 a polynomial with coefficients given densely as an array of Shewchuk
 * floating point expansions from highest to lowest power, e.g. `[[5],[-3],[0]]` 
 * represents the polynomial `5x^2 - 3x`
 * @param p2 another polynomial 
 * 
 * @example
 * ```typescript
 * eEqual([[1],[2],[3],[0,4]], [[1],[2],[3],[4]]);   //=> true
 * eEqual([[1],[2],[3],[4]], [[1],[2],[3],[4],[5]]); //=> false
 * ```
 * 
 * @doc
 */
function eEqual(p1: number[][], p2: number[][]): boolean {
	if (p1.length !== p2.length) { return false; }
	for (let i=0; i<p1.length; i++) {
		if (eCompare(p1[i], p2[i]) !== 0) { return false; }
	}
	return true;
}


export { eEqual }