/* nag_monotonic_deriv (e01bgc) Example Program. * * Copyright 1991 Numerical Algorithms Group. * * Mark 2, 1991. * Mark 8 revised, 2004. */ #include #include #include #include int main(void) { Integer exit_status = 0, i, m, n, r; NagError fail; double *d = 0, *f = 0, *pd = 0, *pf = 0, *px = 0, step, *x = 0; INIT_FAIL(fail); printf("nag_monotonic_deriv (e01bgc) Example Program Results\n"); scanf("%*[^\n]"); /* Skip heading in data file */ scanf("%ld", &n); if (n >= 2) { if (!(x = NAG_ALLOC(n, double)) || !(f = NAG_ALLOC(n, double)) || !(d = NAG_ALLOC(n, double))) { printf("Allocation failure\n"); exit_status = -1; goto END; } } else { printf("Invalid n.\n"); exit_status = 1; return exit_status; } for (r = 0; r < n; r++) scanf("%lf%lf%lf", &x[r], &f[r], &d[r]); scanf("%ld", &m); if (m >= 1) { if (!(pd = NAG_ALLOC(m, double)) || !(pf = NAG_ALLOC(m, double)) || !(px = NAG_ALLOC(m, double))) { printf("Allocation failure\n"); exit_status = -1; goto END; } } else { printf("Invalid m.\n"); exit_status = 1; return exit_status; } /* compute m equally spaced points from x[0] to x[n-1]. */ step = (x[n-1]-x[0]) / (double)(m-1); for (i = 0; i < m; i++) px[i] = MIN(x[0]+i*step, x[n-1]); /* nag_monotonic_deriv (e01bgc). * Evaluation of interpolant computed by * nag_monotonic_interpolant (e01bec), function and first * derivative */ nag_monotonic_deriv(n, x, f, d, m, px, pf, pd, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_monotonic_deriv (e01bgc).\n%s\n", fail.message); exit_status = 1; goto END; } printf(" Interpolated"); printf(" Interpolated\n"); printf(" Abscissa Value"); printf(" Derivative\n"); for (i = 0; i < m; i++) printf("%15.4f %15.4f %15.3e\n", px[i], pf[i], pd[i]); END: if (x) NAG_FREE(x); if (pd) NAG_FREE(pd); if (pf) NAG_FREE(pf); if (px) NAG_FREE(px); if (f) NAG_FREE(f); if (d) NAG_FREE(d); return exit_status; }