cumnormdist()

Complexity

Conditions	2
Paths	2

Size

Total Lines	18
Code Lines	15

Duplication

Lines	0
Ratio	0 %

Importance

Changes

0

<?php
    function cumnormdist($x)
    {
        $b1 =  0.319381530;
        $b2 = -0.356563782;
        $b3 =  1.781477937;
        $b4 = -1.821255978;
        $b5 =  1.330274429;
        $p  =  0.2316419;
        $c  =  0.39894228;

        if ($x >= 0.0) {
            $t = 1.0 / ( 1.0 + $p * $x );
            return (1.0 - $c * exp(-$x * $x / 2.0) * $t *
                ($t *( $t * ($t * ($t * $b5 + $b4) + $b3) + $b2) + $b1));
        } else {
            $t = 1.0 / ( 1.0 - $p * $x );
            return ($c * exp(-$x * $x / 2.0) * $t *
                ($t *($t * ($t * ( $t * $b5 + $b4) + $b3) + $b2) + $b1));
        }