module.exports = length

/**
 * Calculates the length of a vec4
 *
 * @param {vec4} a vector to calculate length of
 * @returns {Number} length of a
 */
function length (a) {
  var x = a[0],
    y = a[1],
    z = a[2],
    w = a[3]
  return Math.sqrt(x * x + y * y + z * z + w * w)
}