!---------------------------------------------------------------------------
!---------------------------------------------------------------------------
!---------------------------------------------------------------------------
!+
! Function subroutine MERIT_1DIM (X)
!
! Function to evaluate the merit function along a line
!-

function merit_1dim (x) result (merit_1)

  use cesrv_struct
  use cesrv_interface
  use super_universe_com

  implicit none

  real(rp), intent(in) :: x
  real(rp) merit0, merit_1, scale

  integer i, j

! The factor of %h_scale is to increase X since BRENT cannot
! handle small numbers.

  scale = logic%h_scale

  do i = 1, size(super%u_(1)%var)
    if (super%u_(1)%var(i)%useit) then
      super%u_(1)%var(i)%model = super%u_(1)%var(i)%old + &
         x * super%u_(1)%var(i)%step * super%u_(1)%var(i)%H / scale
      do j = 1, logic%u_num
        super%u_(j)%var(i)%model = super%u_(1)%var(i)%model
        call var_bookkeeper(super%u_(j)%var(i), super%u_(j)%ring, &
                                                             super%u_(j)%orb)
      enddo
    end if
  end do

  call merit_calc(merit0)
  merit_1 = merit0

  logic%n_1dim_calls = logic%n_1dim_calls + 1  ! count calls

  return

end function