```/* nag_multid_quad_adapt_1 (d01wcc) Example Program.
*
* Copyright 2014 Numerical Algorithms Group.
*
* Mark 5, 1998.
* Mark 7 revised, 2001.
*
*/

#include <nag.h>
#include <stdio.h>
#include <nag_stdlib.h>
#include <math.h>
#include <nagd01.h>

#ifdef __cplusplus
extern "C" {
#endif
static double NAG_CALL f(Integer n, const double z[], Nag_User *comm);
#ifdef __cplusplus
}
#endif

#define NDIM   4
#define MAXPTS 1000*NDIM

int main(void)
{
static Integer use_comm[1] = {1};
Integer  exit_status = 0;
Integer  ndim = NDIM;
Integer  maxpts = MAXPTS;
double   a[4], b[4];
Integer  k;
double   finval;
Integer  minpts;
double   acc, eps;
Nag_User comm;
NagError fail;

INIT_FAIL(fail);

/* For communication with user-supplied functions: */
comm.p = (Pointer)&use_comm;

for (k = 0; k < 4; ++k)
{
a[k] = 0.0;
b[k] = 1.0;
}
eps = 0.0001;
minpts = 0;

*/
&comm, &fail);

if (fail.code != NE_NOERROR && fail.code != NE_QUAD_MAX_INTEGRAND_EVAL)
{
fail.message);
exit_status = 1;
goto END;
}
printf("Requested accuracy =%12.2e\n", eps);
printf("Estimated value    =%12.4f\n", finval);
printf("Estimated accuracy =%12.2e\n", acc);

END:
return exit_status;
}

static double NAG_CALL f(Integer n, const double z[], Nag_User *comm)
{
double tmp_pwr;
Integer *use_comm = (Integer *)comm->p;

if (use_comm[0])
{
printf("(User-supplied callback f, first invocation.)\n");
use_comm[0] = 0;
}

tmp_pwr = z[1]+1.0+z[n-1];
return z[0]*4.0*z[2]*z[2]*exp(z[0]*2.0*z[2])/(tmp_pwr*tmp_pwr);
}
```