NAG Library Manual, Mark 27.3
Interfaces:  FL   CL   CPP   AD
```    Program e04nfae

!     E04NFA Example Program Text

!     Mark 27.3 Release. NAG Copyright 2021.

!     .. Use Statements ..
Use nag_library, Only: e04nfa, e04wbf, e54nfu, nag_wp
!     .. Implicit None Statement ..
Implicit None
!     .. Parameters ..
Integer, Parameter               :: lcwsav = 1, liwsav = 610,            &
llwsav = 120, lrwsav = 475, nin = 5, &
nout = 6
!     .. Local Scalars ..
Real (Kind=nag_wp)               :: obj
Integer                          :: i, ifail, iter, j, lda, ldh, liwork, &
lwork, n, nclin, sda
!     .. Local Arrays ..
Real (Kind=nag_wp), Allocatable  :: a(:,:), ax(:), bl(:), bu(:),         &
clamda(:), cvec(:), h(:,:), work(:), &
x(:)
Real (Kind=nag_wp)               :: ruser(1), rwsav(lrwsav)
Integer, Allocatable             :: istate(:), iwork(:)
Integer                          :: iwsav(liwsav)
Logical                          :: lwsav(llwsav)
Character (80)                   :: cwsav(lcwsav)
!     .. Intrinsic Procedures ..
Intrinsic                        :: max
!     .. Executable Statements ..
Write (nout,*) 'E04NFA Example Program Results'

!     Skip heading in data file

Read (nin,*) n, nclin
liwork = 2*n + 3
lda = max(1,nclin)

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

!     This particular example problem is of type QP2 with H stored explicitly,
!     so we allocate CVEC(N) and H(LDH,N), and define LDH and LWORK as below

ldh = n

If (nclin>0) Then
lwork = 2*n**2 + 8*n + 5*nclin
Else
lwork = n**2 + 8*n
End If

Allocate (istate(n+nclin),ax(max(1,nclin)),iwork(liwork),h(ldh,n),bl(n+  &
nclin),bu(n+nclin),cvec(n),x(n),a(lda,sda),clamda(n+nclin),            &
work(lwork))

!     Initialise E04NFA

ifail = 0
Call e04wbf('E04NFA',cwsav,lcwsav,lwsav,llwsav,iwsav,liwsav,rwsav,       &
lrwsav,ifail)

!     Solve the problem

ifail = -1
Call e04nfa(n,nclin,a,lda,bl,bu,cvec,h,ldh,e54nfu,istate,x,iter,obj,ax,  &
clamda,iwork,liwork,work,lwork,iwsav,ruser,lwsav,iwsav,rwsav,ifail)

Select Case (ifail)
Case (0:5,7:)
Write (nout,*)
Write (nout,99999)
Write (nout,*)

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

If (nclin>0) Then
Write (nout,*)
Write (nout,*)
Write (nout,99997)
Write (nout,*)

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

End If

Write (nout,*)
Write (nout,*)
Write (nout,99995) obj
Write (nout,*)
Write (nout,*)
Write (nout,99994) iter
End Select

99999 Format (1X,'Varbl',2X,'Istate',3X,'Value',9X,'Lagr Mult')
99998 Format (1X,'V',2(1X,I3),4X,1P,G14.6,2X,1P,G12.4)
99997 Format (1X,'L Con',2X,'Istate',3X,'Value',9X,'Lagr Mult')
99996 Format (1X,'L',2(1X,I3),4X,1P,G14.6,2X,1P,G12.4)
99995 Format (1X,'Final objective value = ',G15.7)
99994 Format (1X,'Exit from problem after',1X,I6,1X,'iterations.')
End Program e04nfae
```