Program g05nffe

!     G05NFF Example Program Text

!     Mark 28.3 Release. NAG Copyright 2022.

!     .. Use Statements ..
      Use nag_library, Only: g05kff, g05nff, nag_wp
!     .. Implicit None Statement ..
      Implicit None
!     .. Parameters ..
      Integer, Parameter               :: lseed = 1, nin = 5, nout = 6
!     .. Local Scalars ..
      Integer                          :: genid, i, ifail, j, ldisampl, lipop, &
                                          lstate, m, n, nrs, otype, rtype,     &
                                          subid
!     .. Local Arrays ..
      Real (Kind=nag_wp), Allocatable  :: wt(:)
      Integer, Allocatable             :: ipop(:), isampl(:,:), state(:)
      Integer                          :: seed(lseed)
!     .. Intrinsic Procedures ..
      Intrinsic                        :: max, repeat
!     .. Executable Statements ..
      Write (nout,*) 'G05NFF Example Program Results'
      Write (nout,*)

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

!     Read in the base generator information and seed
      Read (nin,*) genid, subid, seed(1)

!     Initial call to the initializer to get the size of the STATE array
      lstate = 0
      Allocate (state(lstate))
      ifail = 0
      Call g05kff(genid,subid,seed,lseed,state,lstate,ifail)

!     Reallocate STATE
      Deallocate (state)
      Allocate (state(lstate))

!     Initialize the generator to a repeatable sequence
      ifail = 0
      Call g05kff(genid,subid,seed,lseed,state,lstate,ifail)

!     Read in the required resampling method and output type
      Read (nin,*) rtype, otype

!     Read in original sample size, resample size, number of samples
!     and population length
      Read (nin,*) n, m, nrs, lipop

      If (otype==1) Then
        ldisampl = m
      Else
        ldisampl = n
      End If

      Allocate (ipop(lipop),wt(n),isampl(ldisampl,nrs))

      If (lipop==n) Then
!       Read in the population and weights
        Do i = 1, n
          Read (nin,*) ipop(i), wt(i)
        End Do
      Else
!       Read in just the weights
        Do i = 1, n
          Read (nin,*) wt(i)
        End Do
      End If

!     Resample from the population using the supplied weights
      ifail = -1
      Call g05nff(rtype,n,wt,ipop,lipop,m,nrs,otype,isampl,ldisampl,state,     &
        ifail)
      If (ifail==0 .Or. ifail==91) Then
!       IFAIL = 91 is a warning, so we want to continue even if it occurs

!       Display the results
        If (otype==2) Then
          Write (nout,99996) repeat(' ',3*nrs+9), 'Count for Sample'
          Write (nout,99997) 'Value', (j,j=1,nrs)
          Write (nout,99996) repeat('-',max(30,6*nrs+18))
          Do i = 1, n
            If (lipop==0) Then
              Write (nout,99999) i, (isampl(i,j),j=1,nrs)
            Else
              Write (nout,99999) ipop(i), (isampl(i,j),j=1,nrs)
            End If
          End Do

        Else
          Write (nout,99996) repeat(' ',3*nrs), 'Sample'
          Write (nout,99998)(j,j=1,nrs)
          Write (nout,99996) repeat('-',6*nrs+3)
          Do i = 1, m
            Write (nout,99998)(isampl(i,j),j=1,nrs)
          End Do
        End If
      End If

99999 Format (1X,I5,9X,10(1X,I5))
99998 Format (10(1X,I5))
99997 Format (2X,A,8X,10(1X,I5))
99996 Format (3A)
    End Program g05nffe