e3181f26b1
Changed MPI routines to hypre_MPI routines. Added hypre_printf, etc. routines. Added AUTOTEST tests to look for 'int' and 'MPI_' calls. Added a new approach for the Fortran interface (not implemented everywhere yet).
89 lines
2.8 KiB
C
89 lines
2.8 KiB
C
/*BHEADER**********************************************************************
|
|
* Copyright (c) 2008, Lawrence Livermore National Security, LLC.
|
|
* Produced at the Lawrence Livermore National Laboratory.
|
|
* This file is part of HYPRE. See file COPYRIGHT for details.
|
|
*
|
|
* HYPRE is free software; you can redistribute it and/or modify it under the
|
|
* terms of the GNU Lesser General Public License (as published by the Free
|
|
* Software Foundation) version 2.1 dated February 1999.
|
|
*
|
|
* $Revision$
|
|
***********************************************************************EHEADER*/
|
|
|
|
/******************************************************************************
|
|
*
|
|
* This file contains routines that implement a pseudo-random number generator
|
|
* detailed in the following paper.
|
|
*
|
|
* @article{RNG_Park_Miller,
|
|
* author = {S. K. Park and K. W. Miller},
|
|
* title = {Random number generators: good ones are hard to find},
|
|
* journal = {Commun. ACM},
|
|
* volume = {31},
|
|
* number = {10},
|
|
* year = {1988},
|
|
* pages = {1192--1201},
|
|
* }
|
|
*
|
|
* This RNG has been shown to appear fairly random, it is a full period
|
|
* generating function (the sequence uses all of the values available to it up
|
|
* to 2147483647), and can be implemented on any architecture using 32-bit
|
|
* integers. The implementation in this file will not overflow for 32-bit
|
|
* arithmetic, which all modern computers should support.
|
|
*
|
|
* @author David Alber
|
|
* @date March 2005
|
|
*
|
|
*****************************************************************************/
|
|
|
|
#include "_hypre_utilities.h"
|
|
|
|
/*--------------------------------------------------------------------------
|
|
* Static variables
|
|
*--------------------------------------------------------------------------*/
|
|
|
|
static HYPRE_Int Seed = 13579;
|
|
|
|
#define a 16807
|
|
#define m 2147483647
|
|
#define q 127773
|
|
#define r 2836
|
|
|
|
/*--------------------------------------------------------------------------
|
|
* Initializes the pseudo-random number generator to a place in the sequence.
|
|
*
|
|
* @param seed an HYPRE_Int containing the seed for the RNG.
|
|
*--------------------------------------------------------------------------*/
|
|
|
|
void hypre_SeedRand( HYPRE_Int seed )
|
|
{
|
|
Seed = seed;
|
|
}
|
|
|
|
/*--------------------------------------------------------------------------
|
|
* Computes the next pseudo-random number in the sequence using the global
|
|
* variable Seed.
|
|
*
|
|
* @return a double containing the next number in the sequence divided by
|
|
* 2147483647 so that the numbers are in (0, 1].
|
|
*--------------------------------------------------------------------------*/
|
|
|
|
double hypre_Rand()
|
|
{
|
|
HYPRE_Int low, high, test;
|
|
|
|
high = Seed / q;
|
|
low = Seed % q;
|
|
test = a * low - r * high;
|
|
if(test > 0)
|
|
{
|
|
Seed = test;
|
|
}
|
|
else
|
|
{
|
|
Seed = test + m;
|
|
}
|
|
|
|
return ((double)(Seed) / m);
|
|
}
|