# Question concering the Comsol-Matlab interface:postcrossplot

1. May 17, 2011

### PeterMey

Hi,

I have a, maybe quite simple, question concerning the usage of the Matlab interface of comsol, but I wasn't able to figure out the answer by myself.

I use the commands 'postcrossplot' and then 'meshintegrate' for integrating quantities. So far this works fine, but now I want to integrate a quantity not over the whole simulation area but over only a part of it. So I want to define some limits in the 'postcrossplot' command. I guess that I have to define a frame. In the Matlab-help I found that I can define a coordinate frame with the help of a string but no example and since I'm really new to Matlab I tried to define frames on several different ways but however I wasn't able to change the frame used. Therefore I would be really grateful if anyone can give me an example, of how to use postcrossplot for plotting a quantity in only a part of the simulation area.

Thanks,
Peter