Fast Spherical Harmonic Transform

Perform fast spherical harmonic transform and inverse transform using S2kit C code.

Description

A MATLAB interface to S2kit, with routines for spherical harmonic decompositions of spherical data. Computes the fast spherical harmonic transform and its inverse.  
 
S2kit may be obtained from  
http://www.cs.dartmouth.edu/~geelong/sphere/  
 
See README.MEX for more details.  
 
See Test.m and TestInv.m for example scripts.  
 
Chris Rodgers http://rodgers.org.uk/

• MATLAB release: MATLAB 7.0.1 (R14SP1)
• Other requirements: This code was developed using the GNU/Linux operating system and version of Matlab. There is no reason to believe that it will not compile under other operating systems, but I have not attempted to do so.

Other Files

mexs2kit/s2kit10.tar.gz,
mexs2kit/FST_semi_fly_mex.c,
mexs2kit/InvFST_semi_fly_mex.c,
mexs2kit/FST_semi_fly_mex.mexglx,
mexs2kit/InvFST_semi_fly_mex.mexglx,
mexs2kit/FST_semi_fly_mex.m,
mexs2kit/InvFST_semi_fly_mex.m,
mexs2kit/README.MEX,
mexs2kit/LICENSE,
mexs2kit/Test.m,
mexs2kit/TestInv.m,
mexs2kit/Ylm.m,
mexs2kit/MakeFSTGrid.m,
mexs2kit/FSTRep2SphHRep.m,
mexs2kit/SphHRep2FSTRep.m,
mexs2kit/idx2jm.m,
mexs2kit/jm2idx.m

[Enrico Onofri]

The package provides an excellent tool to realize spectral algorithm on the sphere, i.e. solving PDE on S2 with a very efficient representation of the Laplacian. Most welcome

[Geoffrey Adams]

This looks great, but I'm having trouble getting it to work properly. Since I'm running MATLAB on a Mac, I need to recompile the mex files. I followed your instructions, and everything seems to compile fine (and s2kit itself seems to work properly), and the mex commands compile without errors, but when I run Test.m, I get the following error message: 
 
??? Invalid MEX-file '/Users/gadams/Documents/MATLAB/mexs2kit/FST_semi_fly_mex.mexmaci': 
dlopen(/Users/gadams/Documents/MATLAB/mexs2kit/FST_semi_fly_mex.mexmaci, 1): Library not loaded: 
/opt/local/lib/libfftw3.3.dylib 
  Referenced from: /Users/gadams/Documents/MATLAB/mexs2kit/FST_semi_fly_mex.mexmaci 
  Reason: Incompatible library version: FST_semi_fly_mex.mexmaci requires version 6.0.0 or later, but 
  libfftw3.3.dylib provides version 5.0.0. 
 
Error in ==> Test at 37 
    SphHRep=FSTRep2SphHRep(FST_semi_fly_mex(Ylm(j,m,th,ph))); 
 
I have the latest release of FFTW installed on my computer. Do you have any suggestions of anything else I might try? 
 
Thanks!

[Geoffrey Adams]

I was able to get the mex file working properly by compiling it with the FFTW library that ships with MATLAB; now it works great. Thanks for a very useful submission!