text: import number from "./number.js";
  export default function (array, f) {
    var s = 0,
        n = array.length,
        a,
        i = -1,
        j = n;
  
    if (f == null) {
      while (++i < n) if (!isNaN(a = number(array[i]))) s += a;else --j;
    } else {
      while (++i < n) if (!isNaN(a = number(f(array[i], i, array)))) s += a;else --j;
    }
  
    if (j) return s / j;
  }