_math-scale.js 684 Bytes
// https://rwaldron.github.io/proposal-math-extensions/
module.exports = Math.scale || function scale(x, inLow, inHigh, outLow, outHigh) {
  if (
    arguments.length === 0
      // eslint-disable-next-line no-self-compare
      || x != x
      // eslint-disable-next-line no-self-compare
      || inLow != inLow
      // eslint-disable-next-line no-self-compare
      || inHigh != inHigh
      // eslint-disable-next-line no-self-compare
      || outLow != outLow
      // eslint-disable-next-line no-self-compare
      || outHigh != outHigh
  ) return NaN;
  if (x === Infinity || x === -Infinity) return x;
  return (x - inLow) * (outHigh - outLow) / (inHigh - inLow) + outLow;
};