Program f07awfe
! F07AWF Example Program Text
! Mark 30.0 Release. NAG Copyright 2024.
! .. Use Statements ..
Use nag_library, Only: nag_wp, x04dbf, zgetrf, zgetri
! .. Implicit None Statement ..
Implicit None
! .. Parameters ..
Integer, Parameter :: nin = 5, nout = 6
! .. Local Scalars ..
Integer :: i, ifail, info, lda, lwork, n
! .. Local Arrays ..
Complex (Kind=nag_wp), Allocatable :: a(:,:), work(:)
Integer, Allocatable :: ipiv(:)
Character (1) :: clabs(1), rlabs(1)
! .. Executable Statements ..
Write (nout,*) 'F07AWF Example Program Results'
! Skip heading in data file
Read (nin,*)
Read (nin,*) n
lda = n
lwork = 64*n
Allocate (a(lda,n),work(lwork),ipiv(n))
! Read A from data file
Read (nin,*)(a(i,1:n),i=1,n)
! Factorize A
! The NAG name equivalent of zgetrf is f07arf
Call zgetrf(n,n,a,lda,ipiv,info)
Write (nout,*)
Flush (nout)
If (info==0) Then
! Compute inverse of A
! The NAG name equivalent of zgetri is f07awf
Call zgetri(n,a,lda,ipiv,work,lwork,info)
! Print inverse
! ifail: behaviour on error exit
! =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft
ifail = 0
Call x04dbf('General',' ',n,n,a,lda,'Bracketed','F7.4','Inverse', &
'Integer',rlabs,'Integer',clabs,80,0,ifail)
Else
Write (nout,*) 'The factor U is singular'
End If
End Program f07awfe