从PHP中的数组值计算平均增长 [英] Calculating the average increase from array values in PHP

问题描述

我需要计算数组值的平均增加量，并且制作了一个可以运行的小脚本，但是我想知道是否:

I need to calculate the average increase of array values, and I've made a little script which works, but I'd like to know if:

1. 有一种更好，更有效的方法
2. 在计算平均增长率时，我的逻辑是正确的

让我们说我有一个像这样的数组:

Lets say I have an array like so:

$array = array(5,10,15,10,0,15);

我们还可以想象每个数组项是1天，而该值是该天的某个计数器.我想计算柜台上的平均增/减.

Lets also imagine that each array item is 1 day, and the value is some counter for that day. I would like to calculate the average increase/decrease in the counter.

我所做的事情，遍历了数组，并更改了值，以使当前项=当前项-上一项，我将以何种方式留给数组，如下所示:

What I've done, is looped through the array, and altered the values so that the current item = current item - previous item, what way I'm left with an array which would look like so:

$array = array(5,5,-5,-10,15);

然后我按照正常值计算平均值，在此示例中，该平均值将使我每天平均增加2.

Then I calculate the average as per normal, which in this example would give me a 2 average increase on a daily basis.

此处的代码:

$array = array(5,10,15,10,0,15);
$count = count($array);

for($i=0;$i<$count;$i++) {
    if($i==0) {
        $value = $array[$i];
        unset($array[$i]);
    }
    else {
        $tmp = $array[$i];
        $array[$i] -= $value;
        $value = $tmp;
    }
}

echo array_sum($array) / count($array);

这里的逻辑是正确的吗?有没有一种更有效的方式来做到这一点，也许没有循环?

Is the logic correct here, and is there a more efficient way of doing this, maybe without the loop?

先谢谢您了:)

更新了代码以排除第一个值

Updated code to account for excluding first value

推荐答案

这是怎么回事:

function moving_average($array) {

for ($i = 1; $i < sizeof($array); $i++) {
    $result[] = $array[$i] - $array[$i-1];
}

return array_sum($result)/count($result);
}

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