NAG Library Manual, Mark 27.3
```/* nag_fit_dim1_minimax_polynomial (e02alc) Example Program.
*
* Copyright 2021 Numerical Algorithms Group.
*
* Mark 27.3, 2021.
*/
#include <math.h>
#include <nag.h>

int main(void) {

/* Scalars */
Integer exit_status = 0;
double dxx, ref, s, t, xx;
Integer i, j, m, n, neval;
/* Local Arrays */
double *a = 0, *x = 0, *y = 0;
/* NAG types */
NagError fail;

INIT_FAIL(fail);

printf(
"nag_fit_dim1_minimax_polynomial (e02alc) Example Program Results\n\n");

/* Skip heading in data file */
scanf("%*[^\n] ");

/* n is number of data points to be fitted,
* m is degree of fitting polynomial
* neval is number of evaluation points of fitted polynomial
*/
scanf("%" NAG_IFMT "%" NAG_IFMT "%" NAG_IFMT "%*[^\n] ", &n, &m, &neval);

if (!(a = NAG_ALLOC((m + 1), double)) || !(x = NAG_ALLOC((n), double)) ||
!(y = NAG_ALLOC((n), double))) {
printf("Allocation failure\n");
exit_status = -1;
goto END;
}

for (i = 0; i < n; i++)
scanf("%lf%lf", &x[i], &y[i]);
scanf("%*[^\n] ");

/* Fit minimax polynomial of degree m using
* nag_fit_dim1_minimax_polynomial (e02alc).
*/
nag_fit_dim1_minimax_polynomial(n, x, y, m, a, &ref, &fail);
if (fail.code != NE_NOERROR) {
printf("Error from nag_fit_dim1_minimax_polynomial (e02alc).\n%s\n",
fail.message);
exit_status = 1;
goto END;
}
printf("\n  Polynomial coefficients\n");
for (i = 0; i < m + 1; i++)
printf("     %12.4e \n", a[i]);
printf("\n\n  Reference deviation = %10.2e\n\n", ref);
printf("  x      Fit     exp(x)   Residual\n");

/* The neval evaluation points are equispaced on [0,1]. */
dxx = 1.0 / (double)(neval - 1);
for (j = 0; j < neval; j++) {
xx = (double)(j)*dxx;
s = a[m];
for (i = m - 1; i >= 0; i--)
s = s * xx + a[i];
t = exp(xx);
printf("%5.2f%9.4f%9.4f%11.2e\n", xx, s, t, s - t);
}
END:
NAG_FREE(a);
NAG_FREE(x);
NAG_FREE(y);

return exit_status;
}
```