; This command permits, when in zoom mode in 2D, to jump to a zoom 
;window symmetric relatively to the diagonal of the one currently 
;used.
;
;see also : ZOOM ZM
if ($dim != 2) error "Available only in 2D"
if ($zoom != 1) error "Not in ZOOM mode !"
if ($dim == 2) then
   set z1 =  (min(max($zoom_2d[2]*$si1_2d/$si2_2d, 1), $si1_2d) )
   set z2 =  (min(max($zoom_2d[1]*$si2_2d/$si1_2d, 1), $si2_2d) )
   set z3 =  (min(max($zoom_2d[4]*$si1_2d/$si2_2d, 1), $si1_2d) )
   set z4 =  (min(max($zoom_2d[3]*$si2_2d/$si1_2d, 1), $si2_2d) )
;   print ($z1; $z2; $z3; $z4)
   zoom 1 $z1 $z2 $z3 $z4
endif
