Matlab / FreeMat help..

[-Noodles-]

Hey..
This is a bit of a long shot but is anyone on here familiar with Matlab or similar programmes?

I'm trying to do some signal processing for the first time in Matlab for a project and I can't seem to find good tutorials and help (even in my uni..).

http://en.citizendium.org/wiki/Spherical_harmonics
The image showing the harmonics is what I want to recreate. I've got all the formulae but none knows how to turn it into matlab code to achieve that image. I also have found that in Freemat there appears to be no built in Legendre function - which is causing me massive headaches.

Any help would be super appreciated.

 

[johnMM]

So all you're after is recreating the plots?

This is also a long shot, but do you have access to Mathematica or Maple? Like you said, those software packages have lots of the special functions already built in that would make this infinitely easier.

This sort of stuff really isn't Matlab's strength.

EDIT: Actually, you don't really need access to the general Legendre function if you just want to do a few plots of low-order spherical harmonics. They're just real-valued polynomials in cosine (the plots in your link don't have the complex exponential tacked on). You should be able to hard-code them instead of calling the Legendre function itself (Mathematica calls it LegendreP).

This should be do-able in Matlab. Does Matlab have a spherical plot command? I can't remember.

 

[johnMM]

Click on the picture and it gives you the Matlab source code:

http://en.citizendium.org/wiki/File:Spherical_harmonics.png

I found it on accident.

 

[-Noodles-]

Thanks man, just checking that out now to see if I can re-create it in FreeMat.

If not I'll just apply to the university for a copy of Matlab!

edit - dude, that code totally got it! can you pm me your e-mail address.. I want to put you in my thank you list for the thesis.