stats_harmonic_mean
(PECL stats >= 1.0.0)
stats_harmonic_mean — Returns the harmonic mean of an array of values
参数
a-
The input array
返回值
Returns the harmonic mean of the values in a,
or false if a is empty or is not an array.
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用户贡献的备注 1 note
Daniel Morris (www.danielxmorris.com) ¶
16 years ago
I wrote this to calculate harmonic averages in my shares program. Hopefully this can help someone who doesn't want to use PECL. The function accepts an unlimited number of arguments without the need to place them into an array, which is better than the way the PECL extension handles the function.
<?php
/**
* @author Daniel Morris
*/
function harmonic () {
$num_args = func_num_args ();
for ($i = 0; $i < $num_args; $i++) {
$sum += 1 / func_get_arg ($i);
}
return $num_args / $sum;
}
// Tests
echo harmonic (1, 2, 3, 4, 5);
echo harmonic (-1, 3, 4, 10293);
echo harmonic (-1, -2, -3, -4, -5);
// 2.1897810218978
// -9.6022389365052
// -2.1897810218978
?>备份地址：http://www.lvesu.com/blog/php/function.stats-harmonic-mean.php