subroutine   output(pos,npart,ndim,vel,forces,energy,ipas)

!Pour imprimer ce que l'on veut
!Tres primitif

!variables
!vel(npart,ndim):vitesse des particules ,forces(npart,ndim)
!energy: energie
!forces(npart,ndim): forces dur les particules
!npart: nombre de particules
!ndim: dimension de l'espace
!pos(npart,ndim):position des particules
!ipas: instant de simulation
 implicit none
!input
 integer :: ndim,npart,ipas
 double precision :: energy
 double precision :: forces(npart,ndim),pos(npart,ndim),vel(npart,ndim)
!output
 
!local variables
 double precision :: velbar(3)
 integer :: ipart
 integer :: outunit=6, enerunit=8
 namelist /list_output/ ipas, energy
 write(unit=outunit,nml=list_output)
 velbar=0.
 do ipart=1,npart
 velbar(:)=velbar(:)+vel(ipart,:)
 enddo
 return
 end subroutine output
 subroutine close()
 return
 end subroutine close