Imported Upstream version 3.0+20111124upstream/3.0+20111124upstream

1 files changed, 152 insertions, 0 deletions

diff --git a/demo/demo-c.c b/demo/demo-c.c
new file mode 100644
index 0000000..300db4d
--- /dev/null
+++ b/demo/demo-c.c
@@ -0,0 +1,152 @@
+#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;
+}
+