tem_evalMag_forPoint Subroutine

  recursive subroutine tem_evalMag_forPoint( fun, varsys, point, time, tree, &
    &                                        nPnts, res                      )
    ! ---------------------------------------------------------------------- !
    !> Description of the method to obtain the variables, here some preset
    !! values might be stored, like the space time function to use or the
    !! required variables.
    class(tem_varSys_op_type), intent(in) :: fun

    !> The variable system to obtain the variable from.
    type(tem_varSys_type), intent(in) :: varSys

    !> Three-dimensional coordinates at which the variable should be
    !! evaluated. Only useful for variables provided as space-time functions.
    real(kind=rk), intent(in) :: point(:,:)

    !> Point in time at which to evaluate the variable.
    type(tem_time_type), intent(in)  :: time

    !> global treelm mesh info
    type(treelmesh_type), intent(in) :: tree

    !> Number of values to obtain for this variable (vectorized access).
    integer, intent(in) :: nPnts

    !> Resulting values for the requested variable.
    !!
    !! Dimension: n requested entries x nComponents of this variable
    !! Access: (iElem-1)*fun%nComponents + iComp
    real(kind=rk), intent(out) :: res(:)
    ! ---------------------------------------------------------------------- !
    integer :: iPnt, depVar_pos, depVar_nComps, offset
    real(kind=rk), allocatable :: input_varRes(:)
    ! ---------------------------------------------------------------------- !

    ! get the position of dependent variable, assuming only one
    depVar_pos = fun%input_varPos(1)

    ! get the nComp of dependent variable
    depVar_nComps = varSys%method%val( depVar_pos )%nComponents

    ! allocate array to save results
    allocate(input_varRes( nPnts * depVar_nComps ))

    ! derive dependent variable
    call varSys%method%val(depVar_pos)%get_point(                  &
      &                                   varSys = varSys,         &
      &                                   point  = point,          &
      &                                   time   = time,           &
      &                                   tree   = tree,           &
      &                                   nPnts  = nPnts,          &
      &                                   res    = input_varRes(:) )

    ! compute magnitude
    ! assuming fun%nComponents = 1
    input_varRes = input_varRes * input_varRes
    do iPnt = 1, nPnts
      offset = (( ipnt-1)* depvar_ncomps+0)
      res(iPnt) = sqrt(sum(input_varRes(offset+1 : offset+depVar_nComps)))
    end do

    deallocate(input_varRes)

  end subroutine tem_evalMag_forPoint