php - 获取数组中每第 n 个值的平均值

Question

我有以下数组，它们的键是 unix 时间戳，如何在新数组中以每 30 秒的间隔获取平均值，键是 30 秒的间隔？

array (size=61)
1375398000 => int 350
1375398015 => int 357
1375398030 => int 354
1375398045 => int 353
1375398060 => int 361
// and so on...

期望的输出应该是

1375398000 => int 353
1375398030 => int 354

我尝试了一些使用 key($array) 获取第一个值的逻辑，但我无法弄清楚这在 foreach 循环中是否正常工作。

到目前为止我的逻辑

     while($a <= $end){

    $chartData[$a] = $array[$a] //do the average here - current($array) / count($array);

}

我不知道如何获取下一组要使用的键和值

Answer 1

我会这样做，我敢肯定这不是最优雅的，但它完成了工作。

// Make sure the array is in the correct order
ksort($charData);

// This will be our new array
$tmp = array();

$interval = 30;

// Set the array's pointer to the first element
reset($charData); 
$last_timestamp = key($charData);

$total = 0;
$count = 0;

foreach ($charData as $timestamp => $value) {
    $total += $value;
    $count++;

    // If the current timestamp is newer 
    // than 30secs (or any interval set) we record the value
    if($timestamp - $last_timestamp >= $interval) {
        // Calculate the avg
        $tmp[$last_timestamp] = $total / $count;

        // Reset our helper vars
        $last_timestamp = $timestamp;
        $total = 0;
        $count = 0;
    }
}

$charData = $tmp;