home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Language/OS - Multiplatform Resource Library
/
LANGUAGE OS.iso
/
cpp_libs
/
nihcl-30.lha
/
nihcl-3.0
/
lib
/
Random.c
< prev
next >
Wrap
C/C++ Source or Header
|
1990-05-20
|
3KB
|
134 lines
/* Random.c -- implementation of pseudo-random number generator
THIS SOFTWARE FITS THE DESCRIPTION IN THE U.S. COPYRIGHT ACT OF A
"UNITED STATES GOVERNMENT WORK". IT WAS WRITTEN AS A PART OF THE
AUTHOR'S OFFICIAL DUTIES AS A GOVERNMENT EMPLOYEE. THIS MEANS IT
CANNOT BE COPYRIGHTED. THIS SOFTWARE IS FREELY AVAILABLE TO THE
PUBLIC FOR USE WITHOUT A COPYRIGHT NOTICE, AND THERE ARE NO
RESTRICTIONS ON ITS USE, NOW OR SUBSEQUENTLY.
Author:
K. E. Gorlen
Bg. 12A, Rm. 2033
Computer Systems Laboratory
Division of Computer Research and Technology
National Institutes of Health
Bethesda, Maryland 20892
Phone: (301) 496-1111
uucp: uunet!nih-csl!kgorlen
Internet: kgorlen@alw.nih.gov
December, 1985
Function:
A psuedo-random number generator. The function next() returns random
numbers uniformly distributed over the interval (0.0,1.0).
Reference:
Pierre L'ecuyer, "Efficient and Portable Combined Random Number
Generators", Commun. ACM 31, 6 (June 1988), 742-749.
$Log: Random.c,v $
* Revision 3.0 90/05/20 17:40:49 kgorlen
* Release for 1st edition.
*
*/
#include "Random.h"
#include <time.h>
#include "nihclIO.h"
#define THIS Random
#define BASE Object
#define BASE_CLASSES BASE::desc()
#define MEMBER_CLASSES
#define VIRTUAL_BASE_CLASSES Object::desc()
DEFINE_CLASS(Random,2,"$Header: /afs/alw.nih.gov/unix/sun4_40c/usr/local/src/nihcl-3.0/share/lib/RCS/Random.c,v 3.0 90/05/20 17:40:49 kgorlen Rel $",NULL,NULL);
const long s1max = 2147483562;
const long s2max = 2147483398;
void Random::checkSeeds()
{
if (sizeof(long) != 4) {
cerr << "\nRandom only works on 32-bit machines\n";
exit(1);
}
if (s1 < 1 || s1 > s1max) s1 = (ABS(s1) % s1max) + 1;
if (s2 < 1 || s2 > s2max) s2 = (ABS(s2) % s2max) + 1;
}
Random::Random()
{
time(&s1);
s2 = (long)this;
checkSeeds();
}
Random::Random(long seed1, long seed2)
{
s1 = seed1; s2 = seed2;
checkSeeds();
}
float Random::next()
{
long Z,k;
k = s1/53668;
s1 = 40014 * (s1 - k * 53668) - k * 12211;
if (s1 < 0) s1 += s1max + 1;
k = s2/52774;
s2 = 40692 * (s2 - k * 52774) - k * 3791;
if (s2 < 0) s2 += s2max + 1;
Z = s1 - s2;
if (Z < 1) Z += s1max;
return Z * 4.656613E-10;
}
void Random::deepenShallowCopy() {}
unsigned Random::hash() const { return (unsigned)this; }
bool Random::isEqual(const Object& ob) const { return isSame(ob); }
void Random::printOn(ostream& strm) const
{
strm << s1 << ' ' << s2;
}
Random::Random(OIOin& strm)
: BASE(strm)
{
strm >> s1 >> s2;
}
void Random::storer(OIOout& strm) const
{
BASE::storer(strm);
strm << s1 << s2;
}
Random::Random(OIOifd& fd)
: BASE(fd)
{
fd >> s1 >> s2;
}
void Random::storer(OIOofd& fd) const
{
BASE::storer(fd);
fd << s1 << s2;
}
int Random::compare(const Object&) const
{
shouldNotImplement("compare");
return 0;
}