Program e04ncae

!     E04NCA Example Program Text

!     Mark 30.1 Release. NAG Copyright 2024.

!     .. Use Statements ..
      Use nag_library, Only: dgemv, e04nca, e04wbf, nag_wp
!     .. Implicit None Statement ..
      Implicit None
!     .. Parameters ..
      Real (Kind=nag_wp), Parameter    :: one = 1.0_nag_wp
      Real (Kind=nag_wp), Parameter    :: zero = 0.0_nag_wp
      Integer, Parameter               :: inc1 = 1, lcwsav = 1, liwsav = 610,  &
                                          llwsav = 120, lrwsav = 475, nin = 5, &
                                          nout = 6
!     .. Local Scalars ..
      Real (Kind=nag_wp)               :: obj
      Integer                          :: i, ifail, iter, lda, ldc, liwork,    &
                                          lwork, m, n, nclin, sdc
!     .. Local Arrays ..
      Real (Kind=nag_wp), Allocatable  :: a(:,:), b(:), bl(:), bu(:), c(:,:),  &
                                          clamda(:), cvec(:), work(:), x(:)
      Real (Kind=nag_wp)               :: rwsav(lrwsav)
      Integer, Allocatable             :: istate(:), iwork(:), kx(:)
      Integer                          :: iwsav(liwsav)
      Logical                          :: lwsav(llwsav)
      Character (80)                   :: cwsav(lcwsav)
!     .. Intrinsic Procedures ..
      Intrinsic                        :: max
!     .. Executable Statements ..
      Write (nout,*) 'E04NCA Example Program Results'

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

      Read (nin,*) m, n, nclin
      liwork = n
      ldc = max(1,nclin)
      lda = max(1,m)

      If (nclin>0) Then
        sdc = n
      Else
        sdc = 1
      End If

!     This particular example problem is of type LS1, so we allocate
!     A(LDA,N), CVEC(1), B(M) and define LWORK as below

      If (nclin>0) Then
        lwork = 2*n**2 + 9*n + 6*nclin
      Else
        lwork = 9*n
      End If

      Allocate (istate(n+nclin),kx(n),iwork(liwork),c(ldc,sdc),bl(n+nclin),    &
        bu(n+nclin),cvec(1),x(n),a(lda,n),b(m),clamda(n+nclin),work(lwork))

      Read (nin,*)(a(i,1:n),i=1,m)
      Read (nin,*) b(1:m)
      Read (nin,*)(c(i,1:sdc),i=1,nclin)
      Read (nin,*) bl(1:(n+nclin))
      Read (nin,*) bu(1:(n+nclin))
      Read (nin,*) x(1:n)

!     Initialise E04NCA

      ifail = 0
      Call e04wbf('E04NCA',cwsav,lcwsav,lwsav,llwsav,iwsav,liwsav,rwsav,       &
        lrwsav,ifail)

!     Solve the problem

      ifail = -1
      Call e04nca(m,n,nclin,ldc,lda,c,bl,bu,cvec,istate,kx,x,a,b,iter,obj,     &
        clamda,iwork,liwork,work,lwork,lwsav,iwsav,rwsav,ifail)

      Select Case (ifail)
      Case (0:5,7:)
!       Print variable headers
        Write (nout,99999)

        Do i = 1, n
          Write (nout,99998) i, istate(i), x(i), clamda(i)
        End Do

        If (nclin>0) Then

!         C*x --> work
!         The NAG name equivalent of dgemv is f06paf
          Call dgemv('N',nclin,n,one,c,ldc,x,inc1,zero,work,inc1)

!         Print constraint headers
          Write (nout,99997)

          Do i = 1, nclin
            Write (nout,99996) i, istate(i+n), work(i), clamda(i+n)
          End Do

        End If

        Write (nout,99995) obj
      End Select

99999 Format (/,1X,'Varbl',3X,'Istate',4X,'Value',9X,'Lagr Mult')
99998 Format (1X,'V',2(1X,I3),4X,1P,E14.3,2X,1P,E12.3)
99997 Format (/,1X,'L Con',3X,'Istate',4X,'Value',9X,'Lagr Mult')
99996 Format (1X,'L',2(1X,I3),4X,1P,E14.3,2X,1P,E12.3)
99995 Format (/,1X,'Final objective value = ',1P,E15.3)
    End Program e04ncae