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    stats_rand_setall

    (PECL stats >= 1.0.0)

    stats_rand_setall — Set seed values to the random generator

    说明

    stats_rand_setall(int $iseed1, int $iseed2): void

    Set iseed1 and iseed2 as seed values to the random generator used in statistic functions.

    参数

    iseed1

    The value which is used as the random seed

    iseed2

    The value which is used as the random seed

    返回值

    No values are returned.

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    User Contributed Notes 1 note

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    geoffreyj dot lee at gmail dot com
    8 years ago
    tl;dr - This random number generator is implemented using linear congruential generators. The arguments iseed1 and iseed2 each expect a 32-bit integer.

    I can't believe this PECL package has such terrible documentation that I have to dig into the C source code to figure out how to use it.

    Documentation from PECL source, lines 246-262 of "com.c" found at:
    http://git.php.net/?p=pecl/math/stats.git;a=blob;f=com.c;h=7740ac636969e500254c61697125dfa8857dd715;hb=refs/heads/master

    /*
    **********************************************************************
    void setall(long iseed1,long iseed2)
              SET ALL random number generators
    Sets the initial seed of generator 1 to ISEED1 and ISEED2. The
    initial seeds of the other generators are set accordingly, and
    all generators states are set to these seeds.
    This is a transcription from Pascal to Fortran of routine
    Set_Initial_Seed from the paper
    L'Ecuyer, P. and Cote, S. "Implementing a Random Number Package
    with Splitting Facilities." ACM Transactions on Mathematical
    Software, 17:98-111 (1991)
                             Arguments
    iseed1 -> First of two integer seeds
    iseed2 -> Second of two integer seeds
    **********************************************************************
    */

    Looking further into the referenced paper, we see:

    PROCEDURE Set_lnitiaI_Seed (S1, S2 INTEGER);
    Resets the initial seed of generator 1 to the values S1 and S2, which must satisfy: 1 <= S1 <= 2147483562 and 1 <= S2 <= 2147483398. The initial seeds of all other generators are recomputed accordingly, and all generator’s states are reset to these initial seeds. This procedure is called automatically at the beginning of program execution, with (default) parameter values S1 = 1234567890 and S2 = 123456789.
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