PPLANE5 now has the capability of
plotting the nullclines for a planar system. The display of nullclines can be initiated in two ways. If it is initiated in the Setup Window, there results the nulclines with only a few direction field arrows as we see here:
On the other hand, if it is initiated from the Solutions menu in the Display Window, the nullclines are superimposed on the vector field as in this example:
