plotting Phase-Plane Portraits

Hi everyone!

How can I plot phase-plane portraits of a nonlinear system?

[JEAN-CLAUDE boleme]

I NEED HELP WITH QUESTION 3 AND QUESTION 4 REGARDING MATLAB CODES

Answer 1

[Shashank Prasanna]

MATLAB offers several plotting routines. The "quiver" function may be ideal to plot phase-plane portraits. I found an interesting link that has some code and discussion on this topic. You can start here and build up:

http://matlab.cheme.cmu.edu/2011/08/09/phase-portraits-of-a-system-of-odes/

[Sachin Verma]

Thanks. Sir.

[tsen chung jui]

thanks for help !

Answer 2

[Brian Hong]

There are also app solutions for this problem. For example pplane, which I used in undergrad (almost 10 years ago now). We also created a new app for analyzing the phase plane, you can find it here.

Answer 3

[Dan Girma]

xdot = -y, ydot = -x sketch the vector field.