NAG Library Manual, Mark 28.3
```    Program f01zdfe

!     F01ZDF Example Program Text

!     Mark 28.3 Release. NAG Copyright 2022.

!     .. Use Statements ..
Use nag_library, Only: f01zdf, nag_wp, x04daf
!     .. Implicit None Statement ..
Implicit None
!     .. Parameters ..
Integer, Parameter               :: nin = 5, nout = 6
!     .. Local Scalars ..
Integer                          :: i, ifail, kl, ku, lda, ldb, m, n
!     .. Local Arrays ..
Complex (Kind=nag_wp), Allocatable :: a(:,:), b(:,:)
!     .. Executable Statements ..
Write (nout,*) 'F01ZDF Example Program Results'
!     Skip heading in data file
Write (nout,*)
Flush (nout)
Read (nin,*) m, n, kl, ku
lda = n
ldb = lda
Allocate (a(lda,n),b(ldb,n))
!     Read a banded matrix of size m by n. kl is the number of
!     subdiagonals, ku the number of superdiagonals.
Do i = 1, n
End Do
!     Clear the packed matrix array B, so that no elements are
!     unassigned when we print B later.
b(1:(kl+ku+1),1:n) = (0.0E+0_nag_wp,0.0E+0_nag_wp)

!     ifail: behaviour on error exit
!             =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft
ifail = 0
!     Print the unpacked matrix
Call x04daf('G','X',n,n,a,lda,'Unpacked Matrix A:',ifail)

Write (nout,*)
Flush (nout)

!     Convert to packed matrix form
ifail = 0
Call f01zdf('Pack',m,n,kl,ku,a,lda,b,ldb,ifail)

!     Print the packed matrix
ifail = 0
Call x04daf('G','X',kl+ku+1,n,b,ldb,'Packed Matrix B:',ifail)

End Program f01zdfe
```