/* nag_1d_cheb_deriv (e02ahc) Example Program. * * Copyright 2001 Numerical Algorithms Group. * * Mark 7, 2001. */ #include #include #include #include int main(void) { /* Initialized data */ const double xmin = -0.5; const double xmax = 2.5; const double a[7] = { 2.53213, 1.13032, 0.2715, 0.04434, 0.00547, 5.4e-4, 4e-5 }; /* Scalars */ double deriv, deriv2, patm1, x; Integer exit_status, i, m, n, one; NagError fail; /* Arrays */ double *adif = 0, *adif2 = 0; INIT_FAIL(fail); exit_status = 0; printf("nag_1d_cheb_deriv (e02ahc) Example Program Results\n"); n = 6; one = 1; /* Allocate memory */ if (!(adif = NAG_ALLOC(n + 1, double)) || !(adif2 = NAG_ALLOC(n + 1, double))) { printf("Allocation failure\n"); exit_status = -1; goto END; } /* nag_1d_cheb_deriv (e02ahc). * Derivative of fitted polynomial in Chebyshev series form */ nag_1d_cheb_deriv(n, xmin, xmax, a, one, &patm1, adif, one, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_1d_cheb_deriv (e02ahc) call 1.\n%s\n", fail.message); exit_status = 1; goto END; } /* nag_1d_cheb_deriv (e02ahc), see above. */ nag_1d_cheb_deriv(n, xmin, xmax, adif, one, &patm1, adif2, one, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_1d_cheb_deriv (e02ahc) call 2.\n%s\n", fail.message); exit_status = 1; goto END; } m = 4; printf("\n"); printf(" i Argument 1st deriv 2nd deriv\n"); for (i = 1; i <= m; ++i) { x = (xmin * (double)(m - i) + xmax * (double)(i - 1)) / (double)(m - 1); /* nag_1d_cheb_eval2 (e02akc). * Evaluation of fitted polynomial in one variable from * Chebyshev series form */ nag_1d_cheb_eval2(n, xmin, xmax, adif, one, x, &deriv, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_1d_cheb_eval2 (e02akc) call 1.\n%s\n", fail.message); exit_status = 1; goto END; } /* nag_1d_cheb_eval2 (e02akc), see above. */ nag_1d_cheb_eval2(n, xmin, xmax, adif2, one, x, &deriv2, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_1d_cheb_eval2 (e02akc) call 2.\n%s\n", fail.message); exit_status = 1; goto END; } printf("%4ld%9.4f %9.4f %9.4f \n", i, x, deriv, deriv2); } END: NAG_FREE(adif); NAG_FREE(adif2); return exit_status; }