How to use pplane7

Download pplane7 and open Matlab from a terminal.Call pplane7 from the Matlab command windown by typing pplane7.
A new window should pop up. Enter your equations on the window. For example,

pplane

Click the proceed button and another window should appear after some delay


Now you can show the nullclines by clicking Solutions and Show nullclines
Or find an equilibrium point by clicking on Find an equilibrium point. A cross will appear and you will need to click on your window near the point.
Pplane will display the linearization of that critical point and tells you the type.





You can plot trajectories with a certain initial condition by clicking on that coordinate on your pplane window. Before that however, tell pplane to only compute the solution forward in time



Finally, to get a trace of the trajectory as time goes, choose Graph and then Both. After that, choose which trajectory that you want to trace out.