src/math/randomSPRNG.cpp

#include <iostream>
#include <math.h>

#include "math/randomSPRNG.hpp"
#include "utils/simError.h"
#include <sprng.h>

#ifdef IS_MPI

#include <mpi.h>
#endif

using namespace std;

/* randomStreamSPRNF creates a new SPRNG stream for random numbers
 */

int randomSPRNG::nStreamsInitialized = 0;

randomSPRNG::randomSPRNG( int iseed ) {
    int newSeed;
    nStreamsInitialized++;
    newSeed = abs(iseed) + nStreamsInitialized;

    if (newSeed < 0)
        newSeed = abs(newSeed);

#ifdef IS_MPI

    //random number generator should not depend on MpiSimulation
    MPI_Comm_size(MPI_COMM_WORLD, &nSPRNGStreams);
    myStreamNumber = worldRank;

#else

    nSPRNGStreams = 1;
    myStreamNumber = 0;

#endif

    thisStream = init_sprng(GTYPE, myStreamNumber, nSPRNGStreams, newSeed,
                            SPRNG_DEFAULT);
}

randomSPRNG::~randomSPRNG() {
    if (thisStream != NULL) {
        free_sprng(thisStream);
        nStreamsInitialized--;
    }
}

double randomSPRNG::getRandom() { return sprng(thisStream); }

// Gaussian SPRNG class...

double gaussianSPRNG::getGaussian() {
    double ranNum1;
    double ranNum2;
    double gaussianNumber;

    ranNum1 = getRandom();
    ranNum2 = getRandom();

    gaussianNumber = sqrt(-2.0 * log(ranNum1)) * cos(2 * M_PI * ranNum2);

    return gaussianNumber;
}
Revision:	1725
Committed:	Wed Nov 10 22:01:06 2004 UTC (20 years, 11 months ago) by tim
File size:	1320 byte(s)
Log Message:	another painful day (1) SimCreator, SimInfo, mpiSimulation (2) DumpReader, DumpWriter (InitializeFrom File will be removed) (3) ForceField (at least LJ) and BondType, BendType, TorsionType (4)Integrator (5)oopse.cpp (6)visitors & Dump2XYZ (7)SimpleBuilder (8)Constraint & ZConstraint
#	User	Rev	Content
1	gezelter	1490	#include <iostream>
2			#include <math.h>
3
4	tim	1492	#include "math/randomSPRNG.hpp"
5			#include "utils/simError.h"
6	gezelter	1490	#include <sprng.h>
7
8			#ifdef IS_MPI
9	tim	1725
10			#include <mpi.h>
11	gezelter	1490	#endif
12
13			using namespace std;
14
15			/* randomStreamSPRNF creates a new SPRNG stream for random numbers
16			*/
17
18			int randomSPRNG::nStreamsInitialized = 0;
19
20	tim	1725	randomSPRNG::randomSPRNG( int iseed ) {
21			int newSeed;
22			nStreamsInitialized++;
23			newSeed = abs(iseed) + nStreamsInitialized;
24	gezelter	1490
25	tim	1725	if (newSeed < 0)
26			newSeed = abs(newSeed);
27
28	gezelter	1490	#ifdef IS_MPI
29
30	tim	1725	//random number generator should not depend on MpiSimulation
31			MPI_Comm_size(MPI_COMM_WORLD, &nSPRNGStreams);
32			myStreamNumber = worldRank;
33	gezelter	1490
34			#else
35
36	tim	1725	nSPRNGStreams = 1;
37			myStreamNumber = 0;
38	gezelter	1490
39			#endif
40
41	tim	1725	thisStream = init_sprng(GTYPE, myStreamNumber, nSPRNGStreams, newSeed,
42			SPRNG_DEFAULT);
43	gezelter	1490	}
44
45	tim	1725	randomSPRNG::~randomSPRNG() {
46			if (thisStream != NULL) {
47			free_sprng(thisStream);
48			nStreamsInitialized--;
49			}
50	gezelter	1490	}
51
52	tim	1725	double randomSPRNG::getRandom() { return sprng(thisStream); }
53	gezelter	1490
54			// Gaussian SPRNG class...
55
56	tim	1725	double gaussianSPRNG::getGaussian() {
57			double ranNum1;
58			double ranNum2;
59			double gaussianNumber;
60	gezelter	1490
61	tim	1725	ranNum1 = getRandom();
62			ranNum2 = getRandom();
63	gezelter	1490
64	tim	1725	gaussianNumber = sqrt(-2.0 * log(ranNum1)) * cos(2 * M_PI * ranNum2);
65	gezelter	1490
66	tim	1725	return gaussianNumber;
67	gezelter	1490	}