<?php

// Example
$sma_array = simple_sma(array(3,10,11,19,18,12,6,5,9,0), 5);
print_r($sma_array); // Outputs 8, 13.3333, 16, 16.3333, 12, 7.6667, 6.6667, 4.6667

function simple_sma($array, $days) {
    if($days < 0) die("Days have to be higher than 0 in the simple_sma function.");
    $array = array_values($array);
    $x = 0;
    $sma_array = array();
    foreach($array as $key => $val) {
        $x++;
        for($y = 1; $y <= $days; $y++) {
            $sma_array[$key + $y] += ($val / $days);
        }
    }
    $sma_array = array_slice($sma_array, ($days-1), (count($array)-($days-1)) );
    return $sma_array;
}