Program ztprfs_example ! ZTPRFS Example Program Text ! Copyright 2017, Numerical Algorithms Group Ltd. http://www.nag.com ! .. Use Statements .. Use lapack_example_aux, Only: nagf_file_print_matrix_complex_gen_comp Use lapack_interfaces, Only: ztprfs, ztptrs Use lapack_precision, Only: dp ! .. Implicit None Statement .. Implicit None ! .. Parameters .. Integer, Parameter :: nin = 5, nout = 6 Character (1), Parameter :: diag = 'N', trans = 'N' ! .. Local Scalars .. Integer :: i, ifail, info, j, ldb, ldx, n, nrhs Character (1) :: uplo ! .. Local Arrays .. Complex (Kind=dp), Allocatable :: ap(:), b(:, :), work(:), x(:, :) Real (Kind=dp), Allocatable :: berr(:), ferr(:), rwork(:) Character (1) :: clabs(1), rlabs(1) ! .. Executable Statements .. Write (nout, *) 'ZTPRFS Example Program Results' ! Skip heading in data file Read (nin, *) Read (nin, *) n, nrhs ldb = n ldx = n Allocate (ap(n*(n+1)/2), b(ldb,nrhs), work(2*n), x(ldx,n), berr(nrhs), & ferr(nrhs), rwork(n)) ! Read A and B from data file, and copy B to X Read (nin, *) uplo If (uplo=='U') Then Read (nin, *)((ap(i+j*(j-1)/2),j=i,n), i=1, n) Else If (uplo=='L') Then Read (nin, *)((ap(i+(2*n-j)*(j-1)/2),j=1,i), i=1, n) End If Read (nin, *)(b(i,1:nrhs), i=1, n) x(1:n, 1:nrhs) = b(1:n, 1:nrhs) ! Compute solution in the array X Call ztptrs(uplo, trans, diag, n, nrhs, ap, x, ldx, info) ! Compute backward errors and estimated bounds on the ! forward errors Call ztprfs(uplo, trans, diag, n, nrhs, ap, b, ldb, x, ldx, ferr, berr, & work, rwork, info) ! Print solution Write (nout, *) Flush (nout) ! ifail: behaviour on error exit ! =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft ifail = 0 Call nagf_file_print_matrix_complex_gen_comp('General', ' ', n, nrhs, x, & ldx, 'Bracketed', 'F7.4', 'Solution(s)', 'Integer', rlabs, 'Integer', & clabs, 80, 0, ifail) Write (nout, *) Write (nout, *) 'Backward errors (machine-dependent)' Write (nout, 100) berr(1:nrhs) Write (nout, *) 'Estimated forward error bounds (machine-dependent)' Write (nout, 100) ferr(1:nrhs) 100 Format ((5X,1P,4(E11.1,7X))) End Program