source_id = medcalc.LoadDataSource(datafile)
# Field 55 = VITESSE_ELEM_DOM (ON_CELLS)
-presentation_id = medcalc.MakeVectorField(accessField(57), viewMode=MEDCALC.VIEW_MODE_REPLACE,
+presentation_id = medcalc.MakeVectorField(accessField(55), viewMode=MEDCALC.VIEW_MODE_REPLACE,
colorMap=MEDCALC.COLOR_MAP_BLUE_TO_RED_RAINBOW,
scalarBarRange=MEDCALC.SCALAR_BAR_CURRENT_TIMESTEP
)