/* nag_inteq_volterra_weights (d05bwc) Example Program. * * Copyright 2011, Numerical Algorithms Group. * * Mark 23, 2011. */ #include #include #include int main(void) { /* Scalars */ Integer exit_status = 0; Integer i, iorder, j, nomg, p, n; char methodstring[10]; /* Arrays */ double *omega = 0, *sw = 0; /* NAG types */ NagError fail; Nag_ODEMethod method; INIT_FAIL(fail); printf("nag_inteq_volterra_weights (d05bwc) Example Program Results\n"); /* Skip heading in data file*/ scanf("%*[^\n] "); scanf("%9s%*[^\n] ", methodstring); /* * nag_enum_name_to_value (x04nac). * Converts NAG enum member name to value. */ method = (Nag_ODEMethod) nag_enum_name_to_value(methodstring); scanf("%ld%*[^\n] ", &iorder); scanf("%ld%*[^\n] ", &nomg); switch (method) { case Nag_Adams: p = iorder - 1; break; case Nag_BDF: p = iorder; break; } n = nomg + p - 1; if ( !(omega = NAG_ALLOC(nomg, double)) || !(sw = NAG_ALLOC(p*n, double)) ) { printf("Allocation failure\n"); exit_status = -1; goto END; } /* nag_inteq_volterra_weights (d05bwc). Generate weights for use in solving Volterra equations. */ nag_inteq_volterra_weights(method, iorder, nomg, omega, sw, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_inteq_volterra_weights (d05bwc).\n%s\n", fail.message); exit_status = 1; goto END; } printf("\nThe convolution weights\n\n n-j omega\n"); for (j = 0; j < nomg; j++) printf("%3ld %10.4f\n", j+1, omega[j]); printf("\nThe weights W\n"); printf("\n i "); for (j = 0; j < p; j++) printf("%11s%ld ","j = ",j); printf("\n"); #define SW(I, J) sw[J * n + I] for (i = 0; i < n; i++) { printf("%3ld", i+1); for (j = 0; j < p; j++) printf("%13.4f", SW(i, j)); printf("\n"); } #undef SW END: NAG_FREE(sw); NAG_FREE(omega); return exit_status; }