face-api/src/euclideanDistance.ts

export function euclideanDistance(arr1: number[] | Float32Array, arr2: number[] | Float32Array) {
  if (arr1.length !== arr2.length) throw new Error('euclideanDistance: arr1.length !== arr2.length');

  const desc1 = Array.from(arr1);
  const desc2 = Array.from(arr2);

  return Math.sqrt(
    desc1
      .map((val, i) => val - desc2[i])
      .reduce((res, diff) => res + (diff ** 2), 0),
  );
}