Program g10zafe

!     G10ZAF Example Program Text

!     Mark 29.1 Release. NAG Copyright 2023.

!     .. Use Statements ..
      Use nag_library, Only: g10zaf, nag_wp
!     .. Implicit None Statement ..
      Implicit None
!     .. Parameters ..
      Integer, Parameter               :: nin = 5, nout = 6
!     .. Local Scalars ..
      Real (Kind=nag_wp)               :: rss
      Integer                          :: i, ifail, lwt, n, nord
      Character (1)                    :: weight
!     .. Local Arrays ..
      Real (Kind=nag_wp), Allocatable  :: wt(:), wtord(:), x(:), xord(:),      &
                                          y(:), yord(:)
      Integer, Allocatable             :: iwrk(:)
!     .. Executable Statements ..
      Write (nout,*) 'G10ZAF Example Program Results'
      Write (nout,*)

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

!     Read in the problem size
      Read (nin,*) weight, n

      If (weight=='W' .Or. weight=='w') Then
        lwt = n
      Else
        lwt = 0
      End If
      Allocate (x(n),y(n),iwrk(n),wt(lwt),xord(n),yord(n),wtord(n))

!     Read in data
      If (lwt>0) Then
        Read (nin,*)(x(i),y(i),wt(i),i=1,n)
      Else
        Read (nin,*)(x(i),y(i),i=1,n)
      End If

!     Reorder data
      ifail = 0
      Call g10zaf(weight,n,x,y,wt,nord,xord,yord,wtord,rss,iwrk,ifail)

!     Display results
      Write (nout,99999) 'Number of distinct observations = ', nord
      Write (nout,99998) 'Residual sum of squares         = ', rss
      Write (nout,*)
      Write (nout,*) '             X                 Y                 WT'
      Write (nout,99997)(xord(i),yord(i),wtord(i),i=1,nord)

99999 Format (1X,A,I6)
99998 Format (1X,A,F13.5)
99997 Format (5X,F13.5,5X,F13.5,5X,F13.5)
    End Program g10zafe