假设我有4个数组,每个数组里面的值数量相同:
$array1 = array(0, 7, 5, 0);
$array2 = array(2, 6, 10, 0);
$array3 = array(4, 8, 15, 10);
$array4 = array(6, 7, 20, 10);
我想计算这4个数组的每个索引的平均值。因此,我应该得到类似于以下内容的东西:
array(3, 7, 12.5, 5);
假设我有4个数组,每个数组里面的值数量相同:
$array1 = array(0, 7, 5, 0);
$array2 = array(2, 6, 10, 0);
$array3 = array(4, 8, 15, 10);
$array4 = array(6, 7, 20, 10);
array(3, 7, 12.5, 5);
如果你需要使用6个或更多数组,可以使用以下代码来实现更为动态的用法:
$all_arrays = [
array(0, 7, 5, 0),
array(2, 6, 10, 0),
array(4, 8, 15, 10),
array(6, 7, 20, 10),
array(1, 2, 3, 4),
array(5, 6, 7, 8),
// more arrays
];
$each_array_count = count($all_arrays[0]); // 4
$all_arrays_count = count($all_arrays); // 6
$output = [];
for ($i = 0; $i < $each_array_count; $i++) {
for ($j=0; $j < $all_arrays_count; $j++) {
$output[$i] += $all_arrays[$j][$i] / $all_arrays_count;
}
}
echo "<pre>";
var_dump($output);
输出结果: (演示)
Warning: Undefined array key 0 in /in/E783F on line 20
Warning: Undefined array key 1 in /in/E783F on line 20
Warning: Undefined array key 2 in /in/E783F on line 20
Warning: Undefined array key 3 in /in/E783F on line 20
<pre>array(4) {
[0]=>
float(3)
[1]=>
float(6)
[2]=>
float(10)
[3]=>
float(5.333333333333333)
}
我承担了构建一个完全动态函数的任务,您可以输入任意数量的数组。我还添加了一个null
检查,如下面的示例所示,以防您需要跳过数组中的某个值。
# Function takes in unlimited arrays,
# and returns the average of each index of
# those arrays as a new array.
function arrayAverage(...$array){
# Loop through the arrays in the input arguments.
# For every array, extract all numeric values from each
# element, and group them by index in a temporary
# multi-dimensional array. If a value is null, or
# cannot be converted into an integer/float, skip it.
foreach($array as $arr){
for($i = 0; $i < count($arr); $i++){
if(!is_null($arr[$i]) && ($arr[$i] == (int)$arr[$i]))
$temparr[$i][] = (int)$arr[$i];
elseif(!is_null($arr[$i]) && ($arr[$i] == (float)$arr[$i]))
$temparr[$i][] = (float)$arr[$i];
}
}
# Loop through the multi-dimensional array,
# and calculate the average of each.
# Store results in a separate array to
# be returned after the loop is finished.
for($j = 0; $j < count($temparr); $j++)
$averages[] = array_sum($temparr[$j]) / count($temparr[$j]);
# Return aforementioned array containing the averages.
return $averages;
}
# Arrays can have a different amount of key=>value pairs,
# and integer values stored as strings can be parsed,
# as shown in "$array2".
$array1 = array(0, 7, 5, 0);
$array2 = array(2, 6, 10, 0, "100");
$array3 = array(4, 8, 15, 10);
$array4 = array(6, 7, 20, 10);
# Example on how to skip values just in case the need arises
# (So averages won't be affected by having an extra number)
$array5 = array(null, null, null, null, 300);
$averages = arrayAverage($array1, $array2, $array3, $array4, $array5);
print_r($averages);
Array
(
[0] => 3
[1] => 7
[2] => 12.5
[3] => 5
[4] => 200
)
这里有一个简单的解决方案,但你可以进一步概括并使其更加通用,不过现在它能够工作。可以相应地进行更新:
注意:假设数组的计数与您所提到的相同。
$result = [];
for ($i = 0; $i < count($array1); $i++) {
$result [] = ($array1[$i] + $array2[$i] + $array3[$i] + $array4[$i]) / count($array1);
}
dd($result);
/ count($array1)
。 - SirPilancount($array1)
将起作用。 - dev_mustafa(1+1+1+1) / 3
,这已经不是平均值了。 - SirPilan$arrays = [$array1, $array2, $array3, $array4];
$result = [];
for ($i = 0; $i < count($array1); $i++) {
$result[] = array_sum(array_column($arrays, $i)) / count($arrays);
}
正在工作example。
为了获得一个流畅、功能性的代码片段,可以使用array_map()
函数来“转置”数据行。这意味着数据列将被传递到自定义函数中。从那里开始进行平均数计算。
代码:(演示)
$array1 = [0, 7, 5, 0];
$array2 = [2, 6, 10, 0];
$array3 = [4, 8, 15, 10];
$array4 = [6, 7, 20, 10];
var_export(
array_map(
fn() => array_sum(func_get_args()) / func_num_args(),
$array1,
$array2,
$array3,
$array4
)
);
// fn(...$col) => array_sum($col) / count($col), would also work
输出:
array (
0 => 3,
1 => 7,
2 => 12.5,
3 => 5,
)
null
(计为0
)填充列中的空白:Demo。array_map()
中。var_export(array_map(fn() => array_sum(func_get_args()) / func_num_args(), ...$arrays));
var_export(
array_map(
fn(...$col) => array_sum($col) / count(array_filter($col, fn($v) => !is_null($v))),
...$arrays
)
);
// or: fn(...$col) => array_sum($col) / count(array_diff($col, ['']))