rand(3)                             CLIX                             rand(3)



  NAME

    rand, srand - Simple random-number generator

  LIBRARY

    Standard Math Library (libc.a)

  SYNOPSIS

    int rand(
      void );

    void srand(
      unsigned seed );

  PARAMETERS

    seed   An unsigned integer used to initialize the pseudo-random number
           generator.

  DESCRIPTION

    The rand() function uses a multiplicative congruential random-number
    generator with period 2^32 that returns successive pseudo-random numbers
    in the range from 0 to (2^15)-1.

    The srand() function can be called at any time to reset the random-number
    generator to a given starting point.  The generator is initially seeded
    with a value of 1.

  EXAMPLES

    To do fill an array with random integers:

    int index;
    int array[100];
    srand(23);     /*Set the generator.*/
    for(index = 0; index < 100; ++index)
         array[index] = rand();


  NOTES

    The spectral properties of rand() are limited.  The drand48() function
    provides a much better, though more elaborate, random-number generator.

    To compile a program with this function, use the -lm flag to the cc
    command to include the libm.a library.

  RETURN VALUES



  2/94 - Intergraph Corporation                                              1

  rand(3)                             CLIX                             rand(3)



    The rand() function returns a random number between 0 and (2^15)-1.  The
    function srand() does not return a value.

  RELATED INFORMATION

    Functions:  drand48(3)
















































  2                                              Intergraph Corporation - 2/94