check_g2le Subroutine

  subroutine check_g2le
    use file_utils, only: error_unit
    use mp, only: finish_mp, iproc, proc0
    use theta_grid, only: ntgrid
    use gs2_layouts, only: g_lo, le_lo
    use gs2_layouts, only: ig_idx, ik_idx, it_idx, il_idx, ie_idx, is_idx
    use redistribute, only: gather, scatter, report_map_property
    implicit none
    integer :: iglo, ile, ig, isgn, ik, it, il, ie, is, ierr
    integer :: ixi, je
    complex, dimension (:,:,:), allocatable :: gtmp, letmp

    if (proc0) then
       ierr = error_unit()
    else
       ierr = 6
    end if

    ! report the map property
    if (proc0) print *, '=== g2le map property ==='
    call report_map_property (g2le)

    allocate (gtmp(-ntgrid:ntgrid, 2, g_lo%llim_proc:g_lo%ulim_alloc))
    allocate (letmp(nlambda*2+1, negrid+1, le_lo%llim_proc:le_lo%ulim_alloc))
    letmp = 0.

    ! gather check
    gtmp = 0.0
    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)
       ie = ie_idx(g_lo,iglo)
       is = is_idx(g_lo,iglo)
       do isgn = 1, 2
          do ig = -ntgrid, ntgrid
             gtmp(ig,isgn,iglo) = rule(ig,isgn,ik,it,il,ie,is)
          end do
       end do
    end do
    call gather (g2le, gtmp, letmp)
    do ile = le_lo%llim_proc, le_lo%ulim_proc
       ig = ig_idx(le_lo,ile)
       je = jend(ig)
       ik = ik_idx(le_lo,ile)
       it = it_idx(le_lo,ile)
       is = is_idx(le_lo,ile)
       do ie = 1, negrid
          do ixi = 1, 2*nlambda
             isgn = ixi_to_isgn(ixi, ig)
             il = ixi_to_il(ixi, ig)
             if (int(real(letmp(ixi,ie,ile))) /= rule(ig,isgn,ik,it,il,ie,is)) &
                  write (ierr,'(a,8i6)') 'ERROR: gather by g2le broken!', iproc
          end do
       end do
    end do
    if (proc0) write (ierr,'(a)') 'g2le gather check done'

    ! scatter check
    gtmp = 0.0
    call scatter (g2le, letmp, gtmp)
    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)
       ie = ie_idx(g_lo,iglo)
       is = is_idx(g_lo,iglo)
       do isgn = 1, 2
          do ig = -ntgrid, ntgrid
             if (int(real(gtmp(ig,isgn,iglo))) /= rule(ig,isgn,ik,it,il,ie,is)) &
                  write (ierr,'(a,i6)') 'ERROR: scatter by g2le broken!', iproc
          end do
       end do
    end do
    if (proc0) write (ierr,'(a)') 'g2le scatter check done'

    deallocate (gtmp,letmp)

  contains

    function rule (ig, isgn, ik, it, il, ie, is)
      integer, intent (in) :: ig, isgn, ik, it, il, ie, is
      integer :: rule
      rule = ig + isgn + ik + it + il + ie + is  ! make whatever you want
    end function rule

  end subroutine check_g2le