php - 标准正态累积分布函数

Question

标准正态累积分布函数是否有php函数？

我找不到一个。

插件/库也很棒。

请告诉我它在哪里。

非常感谢提前!

stats_cdf_normal

给 Fatal error: Call to undefined function stats_cdf_normal()

Answer 1

有一个未记录的 stats_cdf_normal() PECL stats package 中的函数.

查看本页底部的注释:http://www.php.net/manual/en/ref.stats.php

oliver at •••••••• dot com:

There are some undocumented functions in this extension, eg I found the following by reading the DCDFLIB docs and some trial and error:

<?php

/**
 * stats_cdf_normal($x, $mean, $sd, 1)
 * @return float cumulative probablity
 */
echo stats_cdf_normal(1.96, 0, 1, 1) . "\n";

/**
 * stats_cdf_normal($p, $mean, $sd, 2)
 * @return float x which bounds cumulative probalility $p
 */
echo stats_cdf_normal(0.975, 0, 1, 2) . "\n";

// less useful
// echo stats_cdf_normal(0.4,0.5,0.6,3) . "\n";
// echo stats_cdf_normal(0.4,0.5,0.6,4) . "\n";
?>