/* nag_zpprfs (f07gvc) Example Program. * * Copyright 2001 Numerical Algorithms Group. * * Mark 7, 2001. */ #include #include #include #include #include int main(void) { /* Scalars */ Integer i, j, n, nrhs, ap_len, afp_len; Integer berr_len, ferr_len, pdb, pdx; Integer exit_status = 0; NagError fail; Nag_UploType uplo; Nag_OrderType order; /* Arrays */ char nag_enum_arg[40]; Complex *afp = 0, *ap = 0, *b = 0, *x = 0; double *berr = 0, *ferr = 0; #ifdef NAG_COLUMN_MAJOR #define A_UPPER(I, J) ap[J*(J-1)/2 + I - 1] #define A_LOWER(I, J) ap[(2*n-J)*(J-1)/2 + I - 1] #define B(I, J) b[(J-1)*pdb + I - 1] #define X(I, J) x[(J-1)*pdx + I - 1] order = Nag_ColMajor; #else #define A_LOWER(I, J) ap[I*(I-1)/2 + J - 1] #define A_UPPER(I, J) ap[(2*n-I)*(I-1)/2 + J - 1] #define B(I, J) b[(I-1)*pdb + J - 1] #define X(I, J) x[(I-1)*pdx + J - 1] order = Nag_RowMajor; #endif INIT_FAIL(fail); printf("nag_zpprfs (f07gvc) Example Program Results\n\n"); /* Skip heading in data file */ scanf("%*[^\n] "); scanf("%ld%ld%*[^\n] ", &n, &nrhs); ap_len = n * (n + 1)/2; afp_len = n * (n + 1)/2; berr_len = nrhs; ferr_len = nrhs; #ifdef NAG_COLUMN_MAJOR pdb = n; pdx = n; #else pdb = nrhs; pdx = nrhs; #endif /* Allocate memory */ if (!(afp = NAG_ALLOC(afp_len, Complex)) || !(ap = NAG_ALLOC(ap_len, Complex)) || !(b = NAG_ALLOC(n * nrhs, Complex)) || !(x = NAG_ALLOC(n * nrhs, Complex)) || !(berr = NAG_ALLOC(berr_len, double)) || !(ferr = NAG_ALLOC(ferr_len, double))) { printf("Allocation failure\n"); exit_status = -1; goto END; } /* Read A and B from data file, and copy A to AFP and B to X */ scanf(" %s%*[^\n] ", nag_enum_arg); /* nag_enum_name_to_value(x04nac). * Converts NAG enum member name to value */ uplo = (Nag_UploType) nag_enum_name_to_value(nag_enum_arg); if (uplo == Nag_Upper) { for (i = 1; i <= n; ++i) { for (j = i; j <= n; ++j) scanf(" ( %lf , %lf )", &A_UPPER(i, j).re, &A_UPPER(i, j).im); } scanf("%*[^\n] "); } else { for (i = 1; i <= n; ++i) { for (j = 1; j <= i; ++j) scanf(" ( %lf , %lf )", &A_LOWER(i, j).re, &A_LOWER(i, j).im); } scanf("%*[^\n] "); } 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] "); for (i = 1; i <= n * (n + 1) / 2; ++i) { afp[i-1].re = ap[i-1].re; afp[i-1].im = ap[i-1].im; } for (i = 1; i <= n; ++i) { for (j = 1; j <= nrhs; ++j) { X(i, j).re = B(i, j).re; X(i, j).im = B(i, j).im; } } /* Factorize A in the array AFP */ /* nag_zpptrf (f07grc). * Cholesky factorization of complex Hermitian * positive-definite matrix, packed storage */ nag_zpptrf(order, uplo, n, afp, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_zpptrf (f07grc).\n%s\n", fail.message); exit_status = 1; goto END; } /* Compute solution in the array X */ /* nag_zpptrs (f07gsc). * Solution of complex Hermitian positive-definite system of * linear equations, multiple right-hand sides, matrix * already factorized by nag_zpptrf (f07grc), packed storage */ nag_zpptrs(order, uplo, n, nrhs, afp, x, pdx, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_zpptrs (f07gsc).\n%s\n", fail.message); exit_status = 1; goto END; } /* Improve solution, and compute backward errors and */ /* estimated bounds on the forward errors */ /* nag_zpprfs (f07gvc). * Refined solution with error bounds of complex Hermitian * positive-definite system of linear equations, multiple * right-hand sides, packed storage */ nag_zpprfs(order, uplo, n, nrhs, ap, afp, b, pdb, x, pdx, ferr, berr, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_zpprfs (f07gvc).\n%s\n", fail.message); exit_status = 1; goto END; } /* Print solution */ /* nag_gen_complx_mat_print_comp (x04dbc). * Print complex general matrix (comprehensive) */ fflush(stdout); nag_gen_complx_mat_print_comp(order, Nag_GeneralMatrix, Nag_NonUnitDiag, n, nrhs, x, pdx, 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; } printf("\nBackward errors (machine-dependent)\n"); for (j = 1; j <= nrhs; ++j) printf("%11.1e%s", berr[j-1], j%4 == 0?"\n":" "); printf("\nEstimated forward error bounds (machine-dependent)\n"); for (j = 1; j <= nrhs; ++j) printf("%11.1e%s", ferr[j-1], j%4 == 0?"\n":" "); printf("\n"); END: if (afp) NAG_FREE(afp); if (ap) NAG_FREE(ap); if (b) NAG_FREE(b); if (x) NAG_FREE(x); if (berr) NAG_FREE(berr); if (ferr) NAG_FREE(ferr); return exit_status; }