Program x04dffe

!     X04DFF Example Program Text

!     Mark 30.0 Release. NAG Copyright 2024.

!     .. Use Statements ..
      Use nag_library, Only: f01zdf, nag_wp, x04dff
!     .. Implicit None Statement ..
      Implicit None
!     .. Parameters ..
      Integer, Parameter               :: n = 5, nout = 6
      Character (7), Parameter         :: clabs(n) = (/'Un     ','Deux   ',    &
                                          'Trois  ','Quatre ','Cinq   '/)
      Character (7), Parameter         :: rlabs(n) = (/'Uno    ','Due    ',    &
                                          'Tre    ','Quattro','Cinque '/)
!     .. Local Scalars ..
      Real (Kind=nag_wp)               :: aa
      Integer                          :: i, ifail, indent, j, kl, ku, ku_a,   &
                                          lda, ldab, m, ncols
      Character (19)                   :: form
      Character (1)                    :: job
!     .. Local Arrays ..
      Complex (Kind=nag_wp), Allocatable :: a(:,:), ab(:,:)
!     .. Intrinsic Procedures ..
      Intrinsic                        :: cmplx, max, min, real
!     .. Executable Statements ..
      Write (nout,*) 'X04DFF Example Program Results'

      Write (nout,*)
      Flush (nout)

!     Generate a square array of data.

      m = n
      kl = 1
      ku_a = 2

      lda = m
      Allocate (a(lda,n))

      Do j = 1, n

        Do i = max(1,j-ku_a), min(m,j+kl)
          aa = real(10*i+j,kind=nag_wp)
          a(i,j) = cmplx(aa,-aa,kind=nag_wp)
        End Do

      End Do

!     Convert a to packed storage, ignoring the second superdiagonal.

      ldab = kl + ku_a + 1
      Allocate (ab(ldab,n))

      ku = 1

      job = 'P'

      ifail = 0
      Call f01zdf(job,m,n,kl,ku,a,lda,ab,ldab,ifail)

      ncols = 80
      indent = 0

!     Print m by n band matrix with kl subdiagonals, 1 superdiagonal,
!     default format, bracketed complex numbers, and integer row and
!     column labels

      form = ' '

      ifail = 0
      Call x04dff(m,n,kl,1,ab,ldab,'Bracketed',form,'Example 1:','Integer',    &
        rlabs,'Integer',clabs,ncols,indent,ifail)

      Write (nout,*)
      Flush (nout)

!     Convert the whole matrix a to packed storage.

      ku = ku_a

      job = 'P'

      ifail = 0
      Call f01zdf(job,m,n,kl,ku,a,lda,ab,ldab,ifail)

!     Print (m-1) by (n-1) band matrix with kl subdiagonals,
!     ku superdiagonals, user-supplied format and row and column labels.

      form = 'SS,F7.1,SP,F6.1,''i'''

      ifail = 0
      Call x04dff(m-1,n-1,kl,ku,ab,ldab,'Direct',form,'Example 2:',            &
        'Character',rlabs,'Character',clabs,ncols,indent,ifail)

      Write (nout,*)
      Flush (nout)

!     Print (m-1) by (n-1) band matrix with kl subdiagonals,
!     ku superdiagonals, in MATLAB format.
!     Row and column labelling and USEFRM are ignored.

      form = 'MATLABF7.1'

      ifail = 0
      Call x04dff(m-1,n-1,kl,ku,ab,ldab,' ',form,'A',' ',rlabs,' ',clabs,      &
        ncols,indent,ifail)

    End Program x04dffe