/* nag_sparse_herm_basic_setup (f11grc) Example Program. * * Copyright 2011, Numerical Algorithms Group. * * Mark 23, 2011. */ #include #include #include #include int main(void) { /* Scalars */ Integer exit_status = 0; double anorm, dscale, dtol, sigerr, sigmax, sigtol, stplhs, stprhs, tol; Integer i, irevcm, iterm, itn, its, la, lfill, lwork, lwreq, maxitn, maxits, monit, n, nnz, nnzc, npivm; /* Arrays */ char nag_enum_arg[100]; Complex *a = 0, *b = 0, *work = 0, *x = 0; double *wgt = 0; Integer *icol = 0, *ipiv = 0, *irow = 0, *istr = 0; /* NAG types */ Nag_SparseSym_Method method; Nag_SparseSym_PrecType precon; Nag_SparseSym_Bisection sigcmp; Nag_NormType norm; Nag_SparseSym_Weight weight; Nag_SparseSym_Fact mic; Nag_SparseSym_Piv pstrat; NagError fail, fail1; INIT_FAIL(fail); INIT_FAIL(fail1); printf("nag_sparse_herm_basic_setup (f11grc) Example Program Results\n"); /* Skip heading in data file*/ scanf("%*[^\n]"); scanf("%ld%*[^\n]", &n); scanf("%ld%*[^\n]", &nnz); la = 2 * nnz; lwork = 200; if ( !(a = NAG_ALLOC(la, Complex)) || !(b = NAG_ALLOC(n, Complex)) || !(work = NAG_ALLOC(lwork, Complex)) || !(x = NAG_ALLOC(n, Complex)) || !(wgt = NAG_ALLOC(n, double)) || !(icol = NAG_ALLOC(la, Integer)) || !(ipiv = NAG_ALLOC(n, Integer)) || !(irow = NAG_ALLOC(la, Integer)) || !(istr = NAG_ALLOC(n + 1, Integer)) ) { printf("Allocation failure\n"); exit_status = -1; goto END; } /* Read or initialize the parameters for the iterative solver*/ /* nag_enum_name_to_value(x04nac). * Converts NAG enum member name to value */ scanf("%s%*[^\n] ", nag_enum_arg); method = (Nag_SparseSym_Method) nag_enum_name_to_value(nag_enum_arg); scanf("%s%*[^\n] ", nag_enum_arg); precon = (Nag_SparseSym_PrecType) nag_enum_name_to_value(nag_enum_arg); scanf("%s%*[^\n] ", nag_enum_arg); sigcmp = (Nag_SparseSym_Bisection) nag_enum_name_to_value(nag_enum_arg); scanf("%s%*[^\n] ", nag_enum_arg); norm = (Nag_NormType) nag_enum_name_to_value(nag_enum_arg); scanf("%s%*[^\n] ", nag_enum_arg); weight = (Nag_SparseSym_Weight) nag_enum_name_to_value(nag_enum_arg); scanf("%ld%*[^\n] ", &iterm); scanf("%lf%ld%*[^\n] ", &tol, &maxitn); scanf("%ld%*[^\n] ", &monit); /* Read the parameters for the preconditioner*/ scanf("%ld%lf%*[^\n] ", &lfill, &dtol); scanf("%s%*[^\n] ", nag_enum_arg); mic = (Nag_SparseSym_Fact) nag_enum_name_to_value(nag_enum_arg); scanf("%lf%*[^\n]", &dscale); scanf("%s%*[^\n] ", nag_enum_arg); pstrat = (Nag_SparseSym_Piv) nag_enum_name_to_value(nag_enum_arg); /* Read the non-zero elements of the matrix A*/ for (i = 0; i < nnz; i++) scanf(" ( %lf , %lf ) %ld%ld%*[^\n]", &a[i].re, &a[i].im, &irow[i], &icol[i]); /* Read right-hand side vector b and initial approximate solution x*/ for (i = 0; i < n; i++) scanf(" ( %lf , %lf ) ", &b[i].re, &b[i].im); scanf("%*[^\n]"); for (i = 0; i < n; i++) scanf(" ( %lf , %lf ) ", &x[i].re, &x[i].im); /* Calculate incomplete Cholesky factorization preconditioner using * nag_sparse_herm_chol_fac (f11jnc). * Complex sparse Hermitian matrix, incomplete Cholesky factorization */ nag_sparse_herm_chol_fac(n, nnz, a, la, irow, icol, lfill, dtol, mic, dscale, pstrat, ipiv, istr, &nnzc, &npivm, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_sparse_herm_chol_fac (f11jnc)\n%s\n", fail.message); exit_status = 1; goto END; } /* Initialize the solver using nag_sparse_herm_basic_setup (f11grc). */ anorm = 0.0; sigmax = 0.0; sigtol = 0.01; maxits = n; nag_sparse_herm_basic_setup(method, precon, sigcmp, norm, weight, iterm, n, tol, maxitn, anorm, sigmax, sigtol, maxits, monit, &lwreq, work, lwork, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_sparse_herm_basic_setup (f11grc)\n%s\n", fail.message); exit_status = 2; goto END; } /* Call solver repeatedly to solve the equations * Note that the arrays b and x are overwritten on final exit: * x will contain the solution and b the residual vector */ irevcm = 0; lwreq = lwork; /* First call to nag_sparse_herm_basic_solver (f11gsc). * Complex sparse Hermitian linear systems, preconditioned conjugate * gradient or Lanczos */ nag_sparse_herm_basic_solver(&irevcm, x, b, wgt, work, lwreq, &fail); while (irevcm != 4) { switch (irevcm) { case 1: /* nag_sparse_herm_matvec (f11xsc). * Complex sparse Hermitian matrix vector multiply */ nag_sparse_herm_matvec(n, nnz, a, irow, icol, Nag_SparseSym_NoCheck, x, b, &fail1); break; case 2: /* nag_sparse_herm_precon_ichol_solve (f11jpc). * Solution of complex linear system involving incomplete Cholesky * preconditioning matrix generated by f11jnc */ nag_sparse_herm_precon_ichol_solve(n, a, la, irow, icol, ipiv, istr, Nag_SparseSym_NoCheck, x, b, &fail1); break; case 3: /* nag_sparse_herm_basic_diagnostic (f11gtc). * Complex sparse Hermitian linear systems, diagnostic for f11gsc */ nag_sparse_herm_basic_diagnostic(&itn, &stplhs, &stprhs, &anorm, &sigmax, &its, &sigerr, work, lwreq, &fail1); printf("\nMonitoring at iteration no.%4ld\n", itn); printf("residual norm:%14.4e\n", stplhs); printf("%6sSolution vector%18sResidual vector\n", "", ""); for (i = 0; i < n; i++) printf(" (%11.4e, %11.4e) (%11.4e, %11.4e)\n", x[i].re, x[i].im, b[i].re, b[i].im); printf("\n"); } if (fail1.code != NE_NOERROR) irevcm = 6; /* Next call to nag_sparse_herm_basic_solver (f11gsc). */ nag_sparse_herm_basic_solver(&irevcm, x, b, wgt, work, lwreq, &fail); } if (fail.code != NE_NOERROR) { printf("Error from nag_sparse_herm_basic_solver (f11gsc).\n%s\n", fail.message); exit_status = 3; goto END; } /* Obtain information about the computation using nag_sparse_herm_basic_diagnostic (f11gtc) */ nag_sparse_herm_basic_diagnostic(&itn, &stplhs, &stprhs, &anorm, &sigmax, &its, &sigerr, work, lwreq, &fail); if (fail.code != NE_NOERROR) { printf("Error from nag_sparse_herm_basic_diagnostic (f11gtc)\n%s\n", fail.message); exit_status = 4; goto END; } /* Print the output data*/ printf("Final Results\n"); printf("Number of iterations for convergence: %5ld \n", itn); printf("Residual norm: %14.4e\n", stplhs); printf("Right-hand side of termination criterion: %14.4e \n", stprhs); printf("1-norm of matrix A: %14.4e \n", anorm); printf("Largest singular value of A_bar: %14.4e \n", sigmax); /* Output x*/ printf("\n%6sSolution vector%18sResidual vector\n", "", ""); for (i = 0; i < n; i++) printf(" (%11.4e, %11.4e) (%11.4e, %11.4e)\n", x[i].re, x[i].im, b[i].re, b[i].im); printf("\n"); END: if (a) NAG_FREE(a); if (b) NAG_FREE(b); if (work) NAG_FREE(work); if (x) NAG_FREE(x); if (wgt) NAG_FREE(wgt); if (icol) NAG_FREE(icol); if (ipiv) NAG_FREE(ipiv); if (irow) NAG_FREE(irow); if (istr) NAG_FREE(istr); return exit_status; }