Program g03gafe

!     G03GAF Example Program Text
!     Mark 28.3 Release. NAG Copyright 2022.

!     .. Use Statements ..
      Use nag_library, Only: g03gaf, nag_wp, x04caf
!     .. Implicit None Statement ..
      Implicit None
!     .. Parameters ..
      Integer, Parameter               :: nin = 5, nout = 6
!     .. Local Scalars ..
      Real (Kind=nag_wp)               :: loglik, tol
      Integer                          :: i, ifail, ldprob, lds, ldx, m, n,    &
                                          ng, niter, nvar, popt, riter, sds,   &
                                          sopt
!     .. Local Arrays ..
      Real (Kind=nag_wp), Allocatable  :: f(:,:), g(:,:), prob(:,:), s(:,:,:), &
                                          w(:), x(:,:)
      Integer, Allocatable             :: isx(:)
!     .. Executable Statements ..
      Write (nout,*) 'G03GAF Example Program Results'
      Write (nout,*)
      Flush (nout)

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

!     Problem size
      Read (nin,*) n, m, nvar

!     Number of groups
      Read (nin,*) ng

!     Scaling option
      Read (nin,*) sopt

!     Initial probabilities option
      Read (nin,*) popt

!     Maximum number of iterations
      Read (nin,*) niter

!     Leading dimensions
      ldx = n
      ldprob = n

      Select Case (sopt)
      Case (1)
        Allocate (s(nvar,nvar,ng))
        lds = nvar
        sds = nvar
      Case (2)
        Allocate (s(nvar,nvar,1))
        lds = nvar
        sds = nvar
      Case (3)
        Allocate (s(nvar,ng,1))
        lds = nvar
        sds = ng
      Case (4)
        Allocate (s(nvar,1,1))
        lds = nvar
        sds = 1
      Case Default
        Allocate (s(1,1,1))
        lds = 1
        sds = 1
      End Select

      Allocate (x(ldx,m),prob(ldprob,ng),g(nvar,ng),w(ng),isx(m),f(n,ng))

!     Data matrix X
      Read (nin,*)(x(i,1:m),i=1,n)

!     Included variables
      If (nvar/=m) Then
        Read (nin,*) isx(1:m)
      End If

!     Optionally read initial probabilities of group membership
      If (popt==2) Then
        Read (nin,*)(prob(i,1:ng),i=1,n)
      End If

      tol = 0.0E0_nag_wp
      riter = 5

      ifail = 0
      Call g03gaf(n,m,x,ldx,isx,nvar,ng,popt,prob,ldprob,niter,riter,w,g,sopt, &
        s,lds,sds,f,tol,loglik,ifail)

!     Results
      Write (nout,*)
      Flush (nout)
      ifail = 0
      Call x04caf('g','n',1,ng,w,1,'Mixing proportions',ifail)

      Write (nout,*)
      Flush (nout)
      ifail = 0
      Call x04caf('g','n',nvar,ng,g,nvar,'Group means',ifail)

      Write (nout,*)
      Flush (nout)
      Select Case (sopt)
      Case (1)
        Do i = 1, ng
          ifail = 0
          Call x04caf('g','n',nvar,nvar,s(1,1,i),lds,                          &
            'Variance-covariance matrix',ifail)
        End Do
      Case (2)
        ifail = 0
        Call x04caf('g','n',nvar,nvar,s,lds,                                   &
          'Pooled Variance-covariance matrix',ifail)
      Case (3)
        ifail = 0
        Call x04caf('g','n',nvar,ng,s,lds,'Groupwise Variance',ifail)
      Case (4)
        ifail = 0
        Call x04caf('g','n',nvar,1,s,lds,'Pooled Variance',ifail)
      Case (5)
        ifail = 0
        Call x04caf('g','n',1,1,s,lds,'Overall Variance',ifail)
      End Select

      Write (nout,*)
      Flush (nout)
      ifail = 0
      Call x04caf('g','n',n,ng,f,n,'Densities',ifail)

      Write (nout,*)
      Flush (nout)
      ifail = 0
      Call x04caf('g','n',n,ng,prob,n,'Membership probabilities',ifail)

      Write (nout,*)
      Write (nout,'(1X,A,1X,I16)') 'No. iterations:', niter

      Write (nout,'(1X,A,1X,F16.4)') 'Log-likelihood:', loglik

      Deallocate (x,prob,g,s,w,isx,f)
    End Program g03gafe