3          ivitnum
2 3        ivit1, ivit2
-40e3  -20.0e3  xvito, yvito
100e3 21e3   dxvit ,dyvit
2    2     nxvit ,nyvit
0.0 0.0   vxtran vytran
1.25  0  1.25  0
1.25  0  1.25  0