Question

我是PHP开发的新手，我有一个任务来查找多维数组的每日平均值。由于我从未做过类似的事情，所以我不知道如何做到这一点。任何帮助将深表感谢。这是一段代码：

PrintWriter out = new PrintWriter(source);
out.print("I hate Mondays");
out.close();

我需要这种格式的答案：

 <?php
    $measurements = array(
        '1_DAY_2017' => array('humidity'    => array(15,15,15,15,7,16,11,2), 'temperature'   => array(32,28,27,26,24,24,28,31)),
        '2_DAY_2017' => array('temperature' => array(26,24,24,28,28,26),     'precipitation' => array(12,15,10,12,7,4,2)),
        '3_DAY_2017' => array('humidity'    => array(16,12,15,15,7,16,11,2), 'temperature'   => array(32,28,27,26,24,24,28)),
        '4_DAY_2017' => array('humidity'    => array(11,11,15,15,7,16,10,2), 'temperature'   => array(26,24,24,28,31,31,28,26)),
        '5_DAY_2017' => array('humidity'    => array(12,15,10,12,7,16,2),    'temperature'   => array(25,24,24,28,31,30,27,26)),
        '6_DAY_2017' => array('humidity'    => array(15,11,13,12,7,16,11,2), 'temperature'   => array(25,24,23,28,31,31,27,26)),
        '7_DAY_2017' => array('humidity'    => array(14,15,15,15,7,16,11,2), 'temperature'   => array(26,24,24,28,32,31,28,27)),
    );

我希望它会有所帮助。

Answer 1

$result = [];

foreach ($measurements as $day => $data) {
    foreach ($data as $measurement_type => $values) {
            $result[$day][$measurement_type] = array_sum($values) / count($values);
    }
}

输出：

Array
(
    [1_DAY_2017] => Array
        (
            [humidity] => 12
            [temperature] => 27.5
        )

    [2_DAY_2017] => Array
        (
            [temperature] => 26
            [precipitation] => 8.8571428571429
        )

    [3_DAY_2017] => Array
        (
            [humidity] => 11.75
            [temperature] => 27
        )
    ...

Answer 2

显式：

<?php
$measurements = array(
    '1_DAY_2017' => array('humidity'    => array(15,15,15,15,7,16,11,2), 'temperature'   => array(32,28,27,26,24,24,28,31)),
    '2_DAY_2017' => array('temperature' => array(26,24,24,28,28,26),     'humidity' => array(12,15,10,12,7,4,2)),
);

$average = function(array $nums)
{
    return array_sum($nums)/count($nums);
};

$averages = [];
foreach($measurements as $key => $value)
{
    $averages[$key]['humidity']    = $average($value['humidity']);
    $averages[$key]['temperature'] = $average($value['temperature']);
}

var_export($averages);

输出：

array (
    '1_DAY_2017' => 
    array (
      'humidity' => 12,
      'temperature' => 27.5,
    ),
    '2_DAY_2017' => 
    array (
      'humidity' => 8.857142857142858,
      'temperature' => 26,
    ),
  )

如何在多维数组中找到平均值

2 个答案: