Высчитываение средней медианы

array_median.php

<?php
/*
    Высчитываение средней медианы
    @params array массив чисел
*/
function array_median($array) {
    // perhaps all non numeric values should filtered out of $array here?
    $iCount = count($array);
    if ($iCount == 0) {
      throw new Exception('Median of an empty array is undefined');
    }
    // if we're down here it must mean $array
    // has at least 1 item in the array.
    $middle_index = floor($iCount / 2);
    sort($array, SORT_NUMERIC);
    $median = $array[$middle_index]; // assume an odd # of items
    // Handle the even case by averaging the middle 2 items
    if ($iCount % 2 == 0) {
      $median = ($median + $array[$middle_index - 1]) / 2;
    }
    return $median;
  }

//  пример
echo array_median([12, 16, 80, 70, 11, 14, 13, 20, 10]); // => 14