/* nag_1d_everett_interp (e01abc) Example Program. * * Copyright 2011, Numerical Algorithms Group. * * Mark 23, 2011. */ #include #include #include #include int main(void) { /* Scalars */ Integer exit_status = 0; Integer i, n, r; double p; NagError fail; /* Local Arrays */ double *a = 0, *g = 0; INIT_FAIL(fail); printf("nag_1d_everett_interp (e01abc) Example Program Results\n"); /* Skip heading in data file*/ scanf("%*[^\n] "); scanf("%"NAG_IFMT "", &n); scanf("%lf", &p); scanf("%*[^\n] "); /* Allocate memory */ if (!(a = NAG_ALLOC((2*n), double)) || !(g = NAG_ALLOC((2*n+1), double))) { printf("Allocation failure\n"); exit_status = -1; goto END; } for (i = 0; i < 2*n; i++) scanf("%lf", &a[i]); scanf("%*[^\n] "); /* nag_1d_everett_interp (e01abc). * Interpolated values, Everett's formula, equally spaced data, one variable. */ nag_1d_everett_interp(n, p, a, g, &fail); if (fail.code != NE_NOERROR){ printf("Error from nag_1d_everett_interp (e01abc).\n%s\n", fail.message); exit_status = 1; goto END; } printf("\n"); for (r = 0; r <= n - 1; r++){ printf("Central differences order %"NAG_IFMT " of Y0 = %12.5f\n", r, g[2 * r]); printf(" Y1 = %12.5f\n", g[2 * r + 1]); } printf("\n"); printf("Function value at interpolation point = %12.5f\n", g[2*n]); END: if (a) NAG_FREE(a); if (g) NAG_FREE(g); return exit_status; }