/* nag_zpttrs (f07jsc) Example Program. * * Copyright 2004 Numerical Algorithms Group. * * Mark 23, 2011. */ #include #include #include #include #include int main(void) { /* Scalars */ Integer exit_status = 0, i, j, n, nrhs, pdb; Nag_OrderType order; /* Arrays */ Complex *b = 0, *e = 0; double *d = 0; /* Nag Types */ NagError fail; #ifdef NAG_COLUMN_MAJOR #define B(I, J) b[(J-1)*pdb + I - 1] order = Nag_ColMajor; #else #define B(I, J) b[(I-1)*pdb + J - 1] order = Nag_RowMajor; #endif INIT_FAIL(fail); printf("nag_zpttrs (f07jsc) Example Program Results\n\n"); /* Skip heading in data file */ scanf("%*[^\n]"); scanf("%ld%ld%*[^\n]", &n, &nrhs); if (n < 0 || nrhs < 0) { printf("Invalid n or nrhs\n"); exit_status = 1; goto END; } /* Allocate memory */ if (!(b = NAG_ALLOC(n * nrhs, Complex)) || !(e = NAG_ALLOC(n-1, Complex)) || !(d = NAG_ALLOC(n, double))) { printf("Allocation failure\n"); exit_status = -1; goto END; } #ifdef NAG_COLUMN_MAJOR pdb = n; #else pdb = nrhs; #endif /* Read the upper bidiagonal part of the tridiagonal matrix A from */ /* data file */ for (i = 0; i < n - 1; ++i) scanf(" ( %lf , %lf )", &e[i].re, &e[i].im); scanf("%*[^\n]"); for (i = 0; i < n; ++i) scanf("%lf", &d[i]); scanf("%*[^\n]"); /* Read the right hand matrix B */ for (i = 1; i <= n; ++i) for (j = 1; j <= nrhs; ++j) scanf(" ( %lf , %lf )", &B(i, j).re, &B(i, j).im); scanf("%*[^\n]"); /* Factorize the tridiagonal matrix A using nag_zpttrf (f07jrc). */ nag_zpttrf(n, d, e, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_zpttrf (f07jrc).\n%s\n", fail.message); exit_status = 1; goto END; } /* Solve the equations AX = B using nag_zpttrs (f07jsc). */ nag_zpttrs(order, Nag_Upper, n, nrhs, d, e, b, pdb, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_zpttrs (f07jsc).\n%s\n", fail.message); exit_status = 1; goto END; } /* Print the solution using nag_gen_complx_mat_print_comp (x04dbc). */ fflush(stdout); nag_gen_complx_mat_print_comp(order, Nag_GeneralMatrix, Nag_NonUnitDiag, n, nrhs, b, pdb, Nag_BracketForm, "%7.4f", "Solution(s)", Nag_IntegerLabels, 0, Nag_IntegerLabels, 0, 80, 0, 0, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_gen_complx_mat_print_comp (x04dbc).\n%s\n", fail.message); exit_status = 1; goto END; } END: NAG_FREE(b); NAG_FREE(e); NAG_FREE(d); return exit_status; } #undef B