55 lines
1.6 KiB
JavaScript
55 lines
1.6 KiB
JavaScript
import Returns from '../core/Returns.mjs'
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/* Lifted from mathjs/src/utils/number.js */
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/**
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* Minimum number added to one that makes the result different than one
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*/
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export const DBL_EPSILON = Number.EPSILON || 2.2204460492503130808472633361816E-16
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/**
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* Compares two floating point numbers.
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* @param {number} x First value to compare
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* @param {number} y Second value to compare
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* @param {number} [epsilon] The maximum relative difference between x and y
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* If epsilon is undefined or null, the function will
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* test whether x and y are exactly equal.
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* @return {boolean} whether the two numbers are nearly equal
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*/
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function nearlyEqual (x, y, epsilon) {
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// if epsilon is null or undefined, test whether x and y are exactly equal
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if (epsilon === null || epsilon === undefined) {
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return x === y
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}
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if (x === y) {
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return true
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}
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// NaN
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if (isNaN(x) || isNaN(y)) {
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return false
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}
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// at this point x and y should be finite
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if (isFinite(x) && isFinite(y)) {
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// check numbers are very close, needed when comparing numbers near zero
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const diff = Math.abs(x - y)
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if (diff < DBL_EPSILON) {
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return true
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} else {
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// use relative error
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return diff <= Math.max(Math.abs(x), Math.abs(y)) * epsilon
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}
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}
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// Infinite and Number or negative Infinite and positive Infinite cases
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return false
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}
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/* End of copied section */
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export const compare = {
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'number,number': ({
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config
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}) => Returns(
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'NumInt', (x,y) => nearlyEqual(x, y, config.epsilon) ? 0 : (x > y ? 1 : -1))
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}
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