The Periodicity Toolbox contains MATLAB .m files that implement the periodicity algorithms described in Periodicity Transforms along with a number of demonstrations to get you started.
(1) PTdemos2l gives a simple introduction to the "small to large" algorithm. This is a good place to start.
(2) PTdemomb demos the "M-best" algorithm. Often returns the best results.
(3) PTdemobc shows the "best-correlation" algorithm. Especially good for impulsive data.
(4) PTdemobf demos the "best-frequency" algorithm. By misbehaving, this algorithm shows how important the difference between period and frequency can be.
After downloading, unzip the files and a folder called periodicity will be created. If you put this in your MATLAB path, then you will be able to type
>help periodicity
at the MATLAB prompt for a list of all the functions and .m files. Just type
>PTdemos2l
to view the demo of the "small to large" algorithm. For detailed information about the function type
>help small2large
The files can be found on the CD in the folder Matlab/PeridicityTransform/