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#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "cuba.h"
static inline double Sq(double x)
{
return x*x;
}
static int Integrand(const int *ndim, const double xx[],
const int *ncomp, double ff[], void *userdata)
{
#define x xx[0]
#define y xx[1]
#define z xx[2]
#define f ff[0]
#define FUN 1
const double rsq = Sq(x) + Sq(y) + Sq(z);
#if FUN == 1
f = sin(x)*cos(y)*exp(z);
#elif FUN == 2
f = 1/(Sq(x + y) + .003)*cos(y)*exp(z);
#elif FUN == 3
f = 1/(3.75 - cos(M_PI*x) - cos(M_PI*y) - cos(M_PI*z));
#elif FUN == 4
f = fabs(rsq - .125);
#elif FUN == 5
f = exp(-rsq);
#elif FUN == 6
f = 1/(1 - x*y*z + 1e-10);
#elif FUN == 7
f = sqrt(fabs(x - y - z));
#elif FUN == 8
f = exp(-x*y*z);
#elif FUN == 9
f = Sq(x)/(cos(x + y + z + 1) + 5);
#elif FUN == 10
f = (x > .5) ? 1/sqrt(x*y*z + 1e-5) : sqrt(x*y*z);
#else
f = (rsq < 1) ? 1 : 0;
#endif
return 0;
}
/*********************************************************************/
#define NDIM 3
#define NCOMP 1
#define USERDATA NULL
#define EPSREL 1e-3
#define EPSABS 1e-12
#define LAST 4
#define SEED 0
#define MINEVAL 0
#define MAXEVAL 50000
#define NSTART 1000
#define NINCREASE 500
#define NBATCH 1000
#define GRIDNO 0
#define STATEFILE NULL
#define NNEW 1000
#define FLATNESS 25.
#define KEY1 47
#define KEY2 1
#define KEY3 1
#define MAXPASS 5
#define BORDER 0.
#define MAXCHISQ 10.
#define MINDEVIATION .25
#define NGIVEN 0
#define LDXGIVEN NDIM
#define NEXTRA 0
#define KEY 0
int main()
{
int verbose, comp, nregions, neval, fail;
double integral[NCOMP], error[NCOMP], prob[NCOMP];
const char *env = getenv("CUBAVERBOSE");
verbose = 2;
if( env ) verbose = atoi(env);
printf("-------------------- Vegas test --------------------\n");
Vegas(NDIM, NCOMP, Integrand, USERDATA,
EPSREL, EPSABS, verbose, SEED,
MINEVAL, MAXEVAL, NSTART, NINCREASE, NBATCH,
GRIDNO, STATEFILE,
&neval, &fail, integral, error, prob);
printf("VEGAS RESULT:\tneval %d\tfail %d\n",
neval, fail);
for( comp = 0; comp < NCOMP; ++comp )
printf("VEGAS RESULT:\t%.8f +- %.8f\tp = %.3f\n",
integral[comp], error[comp], prob[comp]);
printf("\n-------------------- Suave test --------------------\n");
Suave(NDIM, NCOMP, Integrand, USERDATA,
EPSREL, EPSABS, verbose | LAST, SEED,
MINEVAL, MAXEVAL, NNEW, FLATNESS,
&nregions, &neval, &fail, integral, error, prob);
printf("SUAVE RESULT:\tnregions %d\tneval %d\tfail %d\n",
nregions, neval, fail);
for( comp = 0; comp < NCOMP; ++comp )
printf("SUAVE RESULT:\t%.8f +- %.8f\tp = %.3f\n",
integral[comp], error[comp], prob[comp]);
printf("\n------------------- Divonne test -------------------\n");
Divonne(NDIM, NCOMP, Integrand, USERDATA,
EPSREL, EPSABS, verbose, SEED,
MINEVAL, MAXEVAL, KEY1, KEY2, KEY3, MAXPASS,
BORDER, MAXCHISQ, MINDEVIATION,
NGIVEN, LDXGIVEN, NULL, NEXTRA, NULL,
&nregions, &neval, &fail, integral, error, prob);
printf("DIVONNE RESULT:\tnregions %d\tneval %d\tfail %d\n",
nregions, neval, fail);
for( comp = 0; comp < NCOMP; ++comp )
printf("DIVONNE RESULT:\t%.8f +- %.8f\tp = %.3f\n",
integral[comp], error[comp], prob[comp]);
printf("\n-------------------- Cuhre test --------------------\n");
Cuhre(NDIM, NCOMP, Integrand, USERDATA,
EPSREL, EPSABS, verbose | LAST,
MINEVAL, MAXEVAL, KEY,
&nregions, &neval, &fail, integral, error, prob);
printf("CUHRE RESULT:\tnregions %d\tneval %d\tfail %d\n",
nregions, neval, fail);
for( comp = 0; comp < NCOMP; ++comp )
printf("CUHRE RESULT:\t%.8f +- %.8f\tp = %.3f\n",
integral[comp], error[comp], prob[comp]);
return 0;
}
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