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 (19 years, 8 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
#	Content
1	#include <iostream>
2	#include <math.h>
3
4	#include "math/randomSPRNG.hpp"
5	#include "utils/simError.h"
6	#include <sprng.h>
7
8	#ifdef IS_MPI
9
10	#include <mpi.h>
11	#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	randomSPRNG::randomSPRNG( int iseed ) {
21	int newSeed;
22	nStreamsInitialized++;
23	newSeed = abs(iseed) + nStreamsInitialized;
24
25	if (newSeed < 0)
26	newSeed = abs(newSeed);
27
28	#ifdef IS_MPI
29
30	//random number generator should not depend on MpiSimulation
31	MPI_Comm_size(MPI_COMM_WORLD, &nSPRNGStreams);
32	myStreamNumber = worldRank;
33
34	#else
35
36	nSPRNGStreams = 1;
37	myStreamNumber = 0;
38
39	#endif
40
41	thisStream = init_sprng(GTYPE, myStreamNumber, nSPRNGStreams, newSeed,
42	SPRNG_DEFAULT);
43	}
44
45	randomSPRNG::~randomSPRNG() {
46	if (thisStream != NULL) {
47	free_sprng(thisStream);
48	nStreamsInitialized--;
49	}
50	}
51
52	double randomSPRNG::getRandom() { return sprng(thisStream); }
53
54	// Gaussian SPRNG class...
55
56	double gaussianSPRNG::getGaussian() {
57	double ranNum1;
58	double ranNum2;
59	double gaussianNumber;
60
61	ranNum1 = getRandom();
62	ranNum2 = getRandom();
63
64	gaussianNumber = sqrt(-2.0 * log(ranNum1)) * cos(2 * M_PI * ranNum2);
65
66	return gaussianNumber;
67	}