Program zgetrs_example
! ZGETRS 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: zgetrf, zgetrs
Use lapack_precision, Only: dp
! .. Implicit None Statement ..
Implicit None
! .. Parameters ..
Integer, Parameter :: nin = 5, nout = 6
Character (1), Parameter :: trans = 'N'
! .. Local Scalars ..
Integer :: i, ifail, info, lda, ldb, n, nrhs
! .. Local Arrays ..
Complex (Kind=dp), Allocatable :: a(:, :), b(:, :)
Integer, Allocatable :: ipiv(:)
Character (1) :: clabs(1), rlabs(1)
! .. Executable Statements ..
Write (nout, *) 'ZGETRS Example Program Results'
! Skip heading in data file
Read (nin, *)
Read (nin, *) n, nrhs
lda = n
ldb = n
Allocate (a(lda,n), b(ldb,nrhs), ipiv(n))
! Read A and B from data file
Read (nin, *)(a(i,1:n), i=1, n)
Read (nin, *)(b(i,1:nrhs), i=1, n)
! Factorize A
Call zgetrf(n, n, a, lda, ipiv, info)
Write (nout, *)
Flush (nout)
If (info==0) Then
! Compute solution
Call zgetrs(trans, n, nrhs, a, lda, ipiv, b, ldb, info)
! Print solution
! 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, &
b, ldb, 'Bracketed', 'F7.4', 'Solution(s)', 'Integer', rlabs, &
'Integer', clabs, 80, 0, ifail)
Else
Write (nout, *) 'The factor U is singular'
End If
End Program