Program f11mdfe

!     F11MDF Example Program Text

!     Mark 28.5 Release. NAG Copyright 2022.

!     .. Use Statements ..
      Use nag_library, Only: f11mdf
!     .. Implicit None Statement ..
      Implicit None
!     .. Parameters ..
      Integer, Parameter               :: nin = 5, nout = 6
!     .. Local Scalars ..
      Integer                          :: ifail, n, nnz
      Character (1)                    :: spec
!     .. Local Arrays ..
      Integer, Allocatable             :: icolzp(:), iprm(:), irowix(:)
!     .. Executable Statements ..
      Write (nout,*) 'F11MDF Example Program Results'
!     Skip heading in data file
      Read (nin,*)

!     Read order of matrix

      Read (nin,*) n

      Allocate (icolzp(n+1),iprm(7*n))

!     Read the matrix

      Read (nin,*) icolzp(1:n+1)
      nnz = icolzp(n+1) - 1

      Allocate (irowix(nnz))

      Read (nin,*) irowix(1:nnz)

!     Calculate COLAMD permutation

      spec = 'M'

!     ifail: behaviour on error exit
!             =0 for hard exit, =1 for quiet-soft, =-1 for noisy-soft
      ifail = 0
      Call f11mdf(spec,n,icolzp,irowix,iprm,ifail)

!     Output results

      Write (nout,*)
      Write (nout,*) 'COLAMD Permutation'
      Write (nout,'(10I6)') iprm(n+1:2*n)

!     Calculate user permutation

      spec = 'U'
      iprm(1) = 4
      iprm(2) = 3
      iprm(3) = 2
      iprm(4) = 1
      iprm(5) = 0

      ifail = 0
      Call f11mdf(spec,n,icolzp,irowix,iprm,ifail)

!     Output results

      Write (nout,*)
      Write (nout,*) 'User Permutation'
      Write (nout,'(10I6)') iprm(n+1:2*n)

!     Calculate natural permutation

      spec = 'N'

      ifail = 0
      Call f11mdf(spec,n,icolzp,irowix,iprm,ifail)

!     Output results

      Write (nout,*)
      Write (nout,*) 'Natural Permutation'
      Write (nout,'(10I6)') iprm(n+1:2*n)

    End Program f11mdfe