PHPのお勉強！

PHP TOP
PHP 8.4.2 Released!

    stats_rand_gen_normal

    (PECL stats >= 1.0.0)

    stats_rand_gen_normal — Generates a single random deviate from a normal distribution

    説明

    stats_rand_gen_normal(float $av, float $sd): float

    Returns a random deviate from the normal distribution with mean, av, and standard deviation, sd.

    パラメータ

    av

    The mean of the normal distribution

    sd

    The standard deviation of the normal distribution

    戻り値

    A random deviate

    Found A Problem?

    Learn How To Improve This Page • Submit a Pull Request • Report a Bug
    ＋add a note

    User Contributed Notes 1 note

    up
    4
    KEINOS
    4 years ago
    Alternative of "stats_rand_gen_normal()".

    <?php
    /**
    * "Box–Muller transform" based random deviate generator.
    *
    * @ref https://en.wikipedia.org/wiki/Box%E2%80%93Muller_transform
    *
    * @param float|int $av Average/Mean
    * @param float|int $sd Standard deviation
    * @return float
    */
    if (! function_exists('stats_rand_gen_normal')) {
    function     stats_rand_gen_normal($av, $sd): float
    {
    $x = mt_rand() / mt_getrandmax();
    $y = mt_rand() / mt_getrandmax();

    return     sqrt(-2 * log($x)) * cos(2 * pi() * $y) * $sd + $av;
    }
    }
    ?>
    ＋add a note
    To Top