NAG Library Manual, Mark 28.5
```    Program f08kwfe

!     F08KWF Example Program Text

!     Mark 28.5 Release. NAG Copyright 2022.

!     .. Use Statements ..
Use nag_library, Only: ddisna, nag_wp, x02ajf, x04daf, zgesvj
!     .. Implicit None Statement ..
Implicit None
!     .. Parameters ..
Integer, Parameter               :: nin = 5, nout = 6
!     .. Local Scalars ..
Real (Kind=nag_wp)               :: eps, serrbd
Integer                          :: i, ifail, info, j, lda, ldv, lrwork, &
lwork, m, n
!     .. Local Arrays ..
Complex (Kind=nag_wp), Allocatable :: a(:,:), cwork(:), v(:,:)
Real (Kind=nag_wp), Allocatable  :: rcondu(:), rcondv(:), rwork(:),      &
sva(:)
!     .. Intrinsic Procedures ..
Intrinsic                        :: abs, max, nint
!     .. Executable Statements ..
Write (nout,*) 'F08KWF Example Program Results'
Write (nout,*)
Flush (nout)
!     Skip heading in data file
lda = m
ldv = n
lwork = n + m
lrwork = max(6,n)
Allocate (a(lda,n),rcondu(m),rcondv(m),sva(n),v(ldv,n),cwork(lwork),     &
rwork(lrwork))

!     Read the m by n matrix A from data file

!     Compute the singular values and left and right singular vectors
!     of A (A = U*S*V, m.ge.n)

!     The NAG name equivalent of zgesvj is f08kwf
Call zgesvj('G','U','V',m,n,a,lda,sva,0,v,ldv,cwork,lwork,rwork,lrwork,  &
info)
If (info==0) Then

!       Compute the approximate error bound for the computed singular values
!       using the 2-norm, s(1) = norm(A), and machine precision, eps.
eps = x02ajf()
serrbd = eps*sva(1)

!       Print solution
Write (nout,*) 'Singular values'
Write (nout,99999)(sva(j),j=1,n)

If (abs(rwork(1)-1.0_nag_wp)>eps) Then
Write (nout,99996) 'Values need scaling by factor = ', rwork(1)
End If
Write (nout,*)
Flush (nout)

!       ifail: behaviour on error exit
!              =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft
ifail = 0
Call x04daf('General',' ',m,n,a,lda,'Left singular vectors',ifail)

Write (nout,*)
Flush (nout)

ifail = 0
Call x04daf('General',' ',n,n,v,ldv,'Right singular vectors',ifail)

!       Call DDISNA (F08FLF) to estimate reciprocal condition
!       numbers for the singular vectors
Call ddisna('Left',m,n,sva,rcondu,info)
Call ddisna('Right',m,n,sva,rcondv,info)

!       Print the approximate error bounds for the singular values
!       and vectors
Write (nout,'(/1X,A)')                                                 &
'Error estimates (as multiples of machine precision):'
Write (nout,'(/1X,A)') '  for the singular values'
Write (nout,99998) nint(serrbd/x02ajf())
Write (nout,'(/1X,A)') '  for left singular vectors'
Write (nout,99998)(nint(serrbd/rcondu(i)/x02ajf()),i=1,n)
Write (nout,'(/1X,A)') '  for right singular vectors'
Write (nout,99998)(nint(serrbd/rcondv(i)/x02ajf()),i=1,n)
Else
Write (nout,99997) 'Failure in ZGESVJ. INFO =', info
End If

99999 Format (3X,(8F8.4))
99998 Format (4X,6I4)
99997 Format (1X,A,I4)
99996 Format (/,1X,A,1P,E13.5)
End Program f08kwfe
```