NAG Library Manual, Mark 30.2
Interfaces:  FL   CL   CPP   AD 

NAG FL Interface Introduction
Example description
!   E04MKF Example Program Text

!   Mark 30.2 Release. NAG Copyright 2024.

    Program e04mkfe

!     .. Use Statements ..
      Use iso_c_binding, Only: c_null_ptr, c_ptr
      Use nag_library, Only: e04mkf, e04mku, e04raf, e04rff, e04rhf, e04rjf,   &
                             e04rwf, e04rzf, e04zmf, nag_wp
!     .. Implicit None Statement ..
      Implicit None
!     .. Parameters ..
      Integer, Parameter               :: nin = 5, nout = 6
!     .. Local Scalars ..
      Type (c_ptr)                     :: cpuser, handle
      Integer                          :: idlc, ifail, ioflag, liarr, m, n,    &
                                          nnza, nnzc, nnzu
!     .. Local Arrays ..
      Real (Kind=nag_wp), Allocatable  :: a(:), bla(:), bua(:), c(:), u(:),    &
                                          x(:), xl(:), xu(:)
      Real (Kind=nag_wp)               :: h(1), rinfo(100), ruser(1),          &
                                          stats(100)
      Integer, Allocatable             :: cindex(:), hs(:), icola(:), irowa(:)
      Integer                          :: icolh(1), irowh(1), iuser(2)
!     .. Executable Statements ..

      Write (nout,*) 'E04MKF Example Program Results'

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

!     read dimensions of the problem
      Read (nin,*) m, n, nnza, nnzc
      nnzu = 2*n + 2*m

!     Allocate memory
      Allocate (cindex(nnzc),icola(nnza),irowa(nnza),a(nnza),bla(m),bua(m),    &
        xl(n),xu(n),c(nnzc),x(n),u(nnzu),hs(m+n))

!     Read problem data
      Read (nin,*) cindex(1:nnzc)
      Read (nin,*) c(1:nnzc)
      Read (nin,*) irowa(1:nnza)
      Read (nin,*) icola(1:nnza)
      Read (nin,*) a(1:nnza)
      Read (nin,*) bla(1:m)
      Read (nin,*) bua(1:m)
      Read (nin,*) xl(1:n)
      Read (nin,*) xu(1:n)
      Read (nin,*) x(1:n)

!     Create the problem handle
!     Initialize handle
      ifail = 0
      Call e04raf(handle,n,ifail)

!     Set objective function
      Call e04rff(handle,nnzc,cindex,c,0,irowh,icolh,h,ifail)

!     Set box constraints
      Call e04rhf(handle,n,xl,xu,ifail)

!     Set linear constraints.
      idlc = 0
      Call e04rjf(handle,m,bla,bua,nnza,irowa,icola,a,idlc,ifail)

!     Turn off option printing
      Call e04zmf(handle,'Print Options = No',ifail)

!     Turn off printing of intermediate progress output
      Call e04zmf(handle,'Print Level = 1',ifail)

!     Require printing of the solution at the end of the solve
      Call e04zmf(handle,'Print Solution = YES',ifail)

!     Call LP simplex solver
      cpuser = c_null_ptr
      ifail = -1
      Call e04mkf(handle,n,x,nnzu,u,rinfo,stats,e04mku,iuser,ruser,cpuser,     &
        ifail)

!     Extract Basis
      ioflag = 1
      liarr = m + n
      Call e04rwf(handle,'Basis',ioflag,liarr,hs,ifail)

!     Free the handle memory
      Call e04rzf(handle,ifail)

    End Program e04mkfe