```/* nag_2d_triangulate (e01eac) Example Program.
*
* Copyright 2017 Numerical Algorithms Group.
*
* Mark 26.2, 2017.
*/

#include <stdio.h>
#include <nag.h>
#include <nag_stdlib.h>
#include <nage01.h>

int main(void)
{

/* Scalars */
Integer exit_status, i, m, n;

/* Arrays */
double *f = 0, *pf = 0, *px = 0, *py = 0, *x = 0, *y = 0;
Integer *triang = 0;

/* Nag Types */
NagError fail;

exit_status = 0;
INIT_FAIL(fail);

printf("nag_2d_triangulate (e01eac) Example Program Results\n\n");

scanf("%*[^\n]");
scanf("%" NAG_IFMT "%*[^\n]", &n);
scanf("%" NAG_IFMT "%*[^\n]", &m);

if (!(x = NAG_ALLOC(n, double)) ||
!(y = NAG_ALLOC(n, double)) ||
!(f = NAG_ALLOC(n, double)) ||
!(triang = NAG_ALLOC(7 * n, Integer)) ||
!(px = NAG_ALLOC(m, double)) ||
!(py = NAG_ALLOC(m, double)) || !(pf = NAG_ALLOC(m, double)))
{
printf("Allocation failure\n");
exit_status = -1;
goto END;
}

/* Read scattered 2d data points and function values. */
for (i = 0; i < n; i++) {
scanf("%lf%lf%lf%*[^\n]", &x[i], &y[i], &f[i]);
}

/* Obtain triangulation of scattered points (x,y) using
* nag_2d_triangulate (e01eac).
*/
nag_2d_triangulate(n, x, y, triang, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_2d_triangulate (e01eac).\n%s\n", fail.message);
exit_status = 1;
goto END;
}

/* Read points at which interpolated values required. */
for (i = 0; i < m; i++) {
scanf("%lf%lf%*[^\n]", &px[i], &py[i]);
}
/* Use triangulation to perform barycentric interpolation on to the
* set of m points (px,py) using nag_2d_triang_bary_eval (e01ebc).
*/
nag_2d_triang_bary_eval(m, n, x, y, f, triang, px, py, pf, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_2d_triang_bary_eval (e01ebc).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}

/* Display results */
printf("    %4s   %7s   %19s\n", "px", "py", "Interpolated Value");
for (i = 0; i < m; i++) {
printf("   %7.4f   %7.4f       %7.4f\n", px[i], py[i], pf[i]);
}

END:
NAG_FREE(f);
NAG_FREE(pf);
NAG_FREE(px);
NAG_FREE(py);
NAG_FREE(x);
NAG_FREE(y);
NAG_FREE(triang);

return exit_status;
}
```