42 lines
1.2 KiB
JavaScript
42 lines
1.2 KiB
JavaScript
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/**
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* Compares two BigNumbers.
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* @param {BigNumber} x First value to compare
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* @param {BigNumber} 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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export 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.eq(y);
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} // use "==" operator, handles infinities
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if (x.eq(y)) {
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return true;
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} // NaN
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if (x.isNaN() || y.isNaN()) {
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return false;
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} // at this point x and y should be finite
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if (x.isFinite() && y.isFinite()) {
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// check numbers are very close, needed when comparing numbers near zero
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var diff = x.minus(y).abs();
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if (diff.isZero()) {
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return true;
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} else {
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// use relative error
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var max = x.constructor.max(x.abs(), y.abs());
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return diff.lte(max.times(epsilon));
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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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