M5 method and MATLAB
I’ve been using M5 method for creating regression trees for a while implemented in WEKA when google suggested me the MATLAB version. It seems quite good and you can find it here.
Archived entries for software
Complex Networks analysis software and MATLAB
If you are interested in complex networks there are some nice libraries to perform analysis, algorithms and nice plotting. At first, I’d suggest Python networkx library, but if you prefer MATLAB the choice must be MatlabBGL a nice toolbox with some useful functions and some simple algorithms. But if you have a 64-bit Apple computer you’ll get crazy trying to install the last release (4.0) of this toolbox because there is a dependency with boost c++ libraries but the last version changed the interface and nothing compiles etc etc. You have two possibilities: try to cope with all this mess installing older version of libraries, changing makefiles and configuration files or, probably better, get the precompiled binaries from here.