ginit_nl5 Subroutine

  subroutine ginit_nl5
    use mp, only: proc0
    use species, only: spec
    use gs2_save, only: gs2_restore
    use theta_grid, only: ntgrid
    use kt_grids, only: naky, ntheta0
    use dist_fn_arrays, only: g, gnew
    use le_grids, only: forbid
    use fields_arrays, only: phi, apar, bpar
    use fields_arrays, only: phinew, aparnew, bparnew
    use gs2_layouts, only: g_lo, ik_idx, it_idx, is_idx, il_idx
    use file_utils, only: error_unit
    use run_parameters, only: has_phi, has_apar, has_bpar
    use ran, only: ranf
    use array_utils, only: copy, zero_array
    implicit none
    complex, dimension (-ntgrid:ntgrid,ntheta0,naky) :: phiz
    integer :: iglo, istatus
    integer :: ig, ik, it, is, il, ierr
    
    call gs2_restore (g, scale, istatus, has_phi, has_apar, has_bpar)
    if (istatus /= 0) then
       ierr = error_unit()
       if (proc0) write(ierr,*) "Error reading file: ", trim(restart_file)
       call zero_array(g)
    end if

    do iglo = g_lo%llim_proc, g_lo%ulim_proc
       ik = ik_idx(g_lo,iglo)
       if (ik == 1) cycle

       g (:,1,iglo) = 0.
       g (:,2,iglo) = 0.
    end do

    phinew(:,:,2:naky) = 0.
    aparnew(:,:,2:naky) = 0.
    bparnew(:,:,2:naky) = 0.
    phi(:,:,2:naky) = 0.
    apar(:,:,2:naky) = 0.
    bpar(:,:,2:naky) = 0.

    do ik = 1, naky
       do it = 1, ntheta0
          do ig = -ntgrid, ntgrid
             phiz(ig,it,ik) = cmplx(ranf()-0.5,ranf()-0.5)
          end do
          if (chop_side) then
             if (left) then
                phiz(:-1,it,ik) = 0.0
             else
                phiz(1:,it,ik) = 0.0
             end if
          end if
       end do
    end do

    do ik = 1, naky
       do it = 1, ntheta0
          do ig = -ntgrid, ntgrid
             phiz(ig,it,ik) = cmplx(ranf()-0.5,ranf()-0.5)
          end do
          if (chop_side) then
             if (left) then
                phiz(:-1,it,ik) = 0.0
             else
                phiz(1:,it,ik) = 0.0
             end if
          end if
       end do
    end do

! reality condition for k_theta = 0 component:
    do it = 1, ntheta0/2
       phiz(:,it+(ntheta0+1)/2,1) = conjg(phiz(:,(ntheta0+1)/2+1-it,1))
    enddo

    do iglo = g_lo%llim_proc, g_lo%ulim_proc
       ik = ik_idx(g_lo,iglo)
       it = it_idx(g_lo,iglo)
       il = il_idx(g_lo,iglo)
       is = is_idx(g_lo,iglo)
       g(:,1,iglo) = g(:,1,iglo)-phiz(:,it,ik)*phiinit*spec(is)%z
       g(:,2,iglo) = g(:,2,iglo)-phiz(:,it,ik)*phiinit*spec(is)%z
       where (forbid(:,il)) g(:,1,iglo) = 0.0
       where (forbid(:,il)) g(:,2,iglo) = 0.0
    end do
    call copy(g, gnew)
  end subroutine ginit_nl5