integrate_species_gf Subroutine

  subroutine integrate_species_gf (g, weights, total)
    use species, only : nspec
    use theta_grid, only: ntgrid
    use gs2_layouts, only: gf_lo, g_lo
    use gs2_layouts, only: is_idx, ik_idx, it_idx, ie_idx, il_idx
    use mp, only: sum_allreduce_sub, sum_allreduce
    use kt_grids, only: kwork_filter
    use redistribute, only: gather
    use species, only: spec, tracer_species
    use array_utils, only: zero_array
    implicit none

    complex, dimension (-ntgrid:,:,g_lo%llim_proc:), intent (in) :: g
    complex, dimension (:, :, :, :, :, :), allocatable :: gf
    real, dimension (:), intent (in out) :: weights
    complex, dimension (-ntgrid:ntgrid,gf_lo%ntheta0,gf_lo%naky), intent (out) :: total
    integer :: is, il, ie, igf, it, ik

    call zero_array(total)
    where (spec%type == tracer_species) weights = 0
    allocate(gf(-ntgrid:ntgrid,2,nspec,negrid,nlambda,gf_lo%llim_proc:gf_lo%ulim_alloc))
    call gather(g2gf, g, gf, ntgrid)

    !Performed integral (weighted sum) over local velocity space and species
    if(any(kwork_filter)) then
       do igf = gf_lo%llim_proc,gf_lo%ulim_proc
          it = it_idx(gf_lo,igf)
          ik = ik_idx(gf_lo,igf)
          if(kwork_filter(it,ik)) cycle
          do il = 1,gf_lo%nlambda
             do ie = 1,gf_lo%negrid
                do is = 1,gf_lo%nspec
                   total(:,it,ik) = total(:,it,ik) + &
                        (weights(is)*w(ie,is))*wl(:,il)*(gf(:,1,is,ie,il,igf)+gf(:,2,is,ie,il,igf))
                end do
             end do
          end do
       end do
    else
       do igf = gf_lo%llim_proc,gf_lo%ulim_proc
          it = it_idx(gf_lo,igf)
          ik = ik_idx(gf_lo,igf)
          do il = 1,gf_lo%nlambda
             do ie = 1,gf_lo%negrid
                do is = 1,gf_lo%nspec
                   total(:,it,ik) = total(:,it,ik) + &
                        (weights(is)*w(ie,is))*wl(:,il)*(gf(:,1,is,ie,il,igf)+gf(:,2,is,ie,il,igf))
                end do
             end do
          end do
       end do
    end if

    deallocate(gf)
  end subroutine integrate_species_gf