avg_dv Subroutine

  subroutine avg_dv (dv, dv_hist, istep, navg)  
    use mp, only: proc0
    implicit none
    type (dens_vel_diagnostics), intent(in out) :: dv
    type (dens_vel_diagnostics), dimension (0:), intent(in out) :: dv_hist
    integer, intent (in) :: istep, navg
    integer :: i

    if (proc0) then
       if (navg > 1) then
          if (istep > 1) then
             dv_hist(mod(istep,navg)) % dvpar(:)     = dv % dvpar(:)
             dv_hist(mod(istep,navg)) % dvperp(:)    = dv % dvperp(:)
             dv_hist(mod(istep,navg)) % dn(:)        = dv % dn(:)
          end if
          
          if (istep >= navg) then
             call zero_dvtype(dv)
             do i=0,navg-1
                dv % dvpar(:)  = dv % dvpar(:)  + dv_hist(i) % dvpar(:)  / real(navg)
                dv % dvperp(:) = dv % dvperp(:) + dv_hist(i) % dvperp(:) / real(navg)
                dv % dn(:)     = dv % dn(:)     + dv_hist(i) % dn (:)    / real(navg)
             end do
          end if
       end if
    end if

  end subroutine avg_dv