Program f03bafe

!     F03BAF Example Program Text

!     Mark 27.3 Release. NAG Copyright 2021.

!     .. Use Statements ..
      Use nag_library, Only: dgetrf, f03baf, nag_wp, x04caf
!     .. Implicit None Statement ..
      Implicit None
!     .. Parameters ..
      Integer, Parameter               :: nin = 5, nout = 6
!     .. Local Scalars ..
      Real (Kind=nag_wp)               :: d
      Integer                          :: i, id, ifail, info, lda, n
!     .. Local Arrays ..
      Real (Kind=nag_wp), Allocatable  :: a(:,:)
      Integer, Allocatable             :: ipiv(:)
!     .. Executable Statements ..
      Write (nout,*) 'F03BAF Example Program Results'

!     Skip heading in data file
      Read (nin,*)

      Read (nin,*) n
      lda = n
      Allocate (a(lda,n),ipiv(n))

      Read (nin,*)(a(i,1:n),i=1,n)

!     LU Factorize A
!     The NAG name equivalent of dgetrf is f07adf
      Call dgetrf(n,n,a,lda,ipiv,info)

      Write (nout,*)
      Flush (nout)
      ifail = 0
      Call x04caf('G','N',n,n,a,lda,'Array A after factorization',ifail)

      Write (nout,*)
      Write (nout,*) 'Pivots'
      Write (nout,99999) ipiv(1:n)
      Write (nout,*)
      Flush (nout)

      ifail = 0
      Call f03baf(n,a,lda,ipiv,d,id,ifail)

      Write (nout,99998) d, id
      Write (nout,*)
      Write (nout,99997) d*2.0_nag_wp**id

99999 Format (1X,8(1X,I13))
99998 Format (1X,'D = ',F13.5,' ID = ',I12)
99997 Format (1X,'Value of determinant = ',E13.5)
    End Program f03bafe