ga_evaluate.f

      FUNCTION ga_evaluate(fcn, nopt, fvec, n, x, iflag, nfev)
      USE stel_kinds
      INTEGER :: n, nfev
      REAL(rprec) :: ga_evaluate
      REAL(rprec), DIMENSION(n) :: x
      INTEGER :: nopt
      REAL(rprec), DIMENSION(nopt) :: fvec
      EXTERNAL  fcn
 
      INTEGER :: iflag
 
      CALL fcn(nopt, n, x, fvec, iflag, nfev)
      ga_evaluate = -sum(fvec(:nopt)**2)
 
      END FUNCTION ga_evaluate