stats_cdf_poisson

(PECL stats >= 1.0.0)

stats_cdf_poisson — Calculates any one parameter of the Poisson distribution given values for the others.

Description

float stats_cdf_poisson ( float $par1 , float $par2 , int $which )

Warning

This function is currently not documented; only its argument list is available.

Parameters

par1
par2
which

Return Values

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s at nder dot com ¶

5 months ago


A simple poisson-distribution function, which only works for relatively small numbers (maximum of ~100/100 for most systems):



<?php



function factorial($number)

{

        if ($number < 2) {

                return 1;

        } else {

                return ($number * factorial($number-1));

        }

}



function poisson($chance, $occurrence)

{

        $e = exp(1);



        $a = pow($e, (-1 * $chance));

        $b = pow($chance,$occurrence);

        $c = factorial($occurrence);



        return $a * $b / $c;

}



$test = poisson(100,100);

echo $test . "\n";



?>

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