vectors/normalize-nd.js

A grab bag of vector utility functions for 2D and 3D vectors that operate on plain arrays

module.exports = normalize

function normalize(vec) {
  var mag = 0
  for (var n = 0; n < vec.length; n++) {
    mag += vec[n] * vec[n]
  }
  mag = Math.sqrt(mag)

  // avoid dividing by zero
  if (mag === 0) {
    return Array.apply(null, new Array(vec.length)).map(Number.prototype.valueOf, 0)
  }

  for (var n = 0; n < vec.length; n++) {
    vec[n] /= mag
  }

  return vec
}