Get SD

by stopsatgreen

JavaScript

const inputArray = [1,2,3];

function standardDeviation (values) {

  function getMean (arr) {
    const sum = arr.reduce((sum, value) => {
      return sum + value;
    }, 0);
    return sum / arr.length;
  }

  const avg = getMean(values);
  const squaredDiffs = values.map((value) => {
  	return Math.pow(value - avg, 2);
  });

	const variance = getMean(squaredDiffs);
  const stdDev = Math.sqrt(variance);
  return stdDev;
}

console.log(standardDeviation(inputArray));