Statistic 函数

Table of Contents

User Contributed Notes

Anonymous 08-May-2013 12:09
The source code actually has much more complete documentation (more functions, a better description of what they do, and parameters). You can see the latest here:
http://svn.php.net/viewvc/pecl/stats/trunk/

Notably, try clicking the latest revision number for php_stats.c
oliver at realtsp dot com 25-Jul-2008 10:17
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, 1)
 * @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";
?>