stats_harmonic_mean
(PECL stats >= 1.0.0)
stats_harmonic_mean — Returns the harmonic mean of an array of values
说明
$a
)本函数还未编写文档，仅有参数列表。
参数
-
a -
返回值
用户评论:
[#1] Daniel Morris (www.danielxmorris.com) [2008-08-15 07:51:17]
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
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
?>