How to plot ODE solution after a certain time?

Hi,

I'm plotting phase portraits for the Lorenz system and I'm wondering if I can plot after a certain time t so I'm only plotting a limit cycle and none of the transient behaviour before hand.

I know I can change my x,y and z limits with xlim ([ ]) etc but this doesn't seem to work if I try tlim.

Any suggestions?

Thanks

Answer 1

[Are Mjaavatten]

Let us use the Matlab code on the Wikipedia Lorenz system page as an example:

https://en.wikipedia.org/wiki/Lorenz_system

Running this code gives you a vector t and a result matrix a. You can plot a for times greater than 50 only, by:

 iplot = find(t>50);
 plot3(a(iplot,1),a(iplot,2),a(iplot,3));grid on

To see how the curve develops, you may also try comet3:

 comet3(a(:,1),a(:,2),a(:,3))