Welcome to the VSAA community!
VSAA is an algorithmic procedure for frequency analysis in various types of signals. It can be used supplementary to Fourier Transform (FT) and Wavelet Analysis (WA) in cases where one needs a single and simple description of the signal. It is based on a partial fit of the data set using the Simplex Algorithm. It decodes the signal and produces a time-variable frequency along with its amplitude. As it encloses the ‘sliding window’ technique, it can be used for extracting local-frequency information from the signal.

SCIENCE
The scientific reference can be found in arXiv:0709.3224 : S. Tsantilas and H. Rovithis- Livaniou : Variable Sine Algorithmic Analysis (VSAA): A new method of frequency analysis-Applications.

HELP 
A ‘survival guide’ can be downloaded here
(YOU MUST READ IT!!!) 

THE PROGRAM
The program is available in executable form: 
VSAA ver. 2.1 (CHOOSE DOWNLOAD, or right click – save target as)
If you use this program for a scientific paper or any type of public presentation, you should make a reference to:
arXiv:0709.3224: S. Tsantilas and H. Rovithis- Livaniou : Variable Sine Algorithmic Analysis (VSAA): A new method of frequency analysis-Applications.

REQUIREMENTS
The VSAA code should run in every Windows platform (from Win95 to Vista). If you find any problems, please take a minute to report it to me.

EXAMPLES
1. Period variation of AB And eclipsing binary
Input data file (Save it to the same directory that you used for the executable program)
Input parameters (Save it to the same directory that you used for the executable program)

2. Wolf’s sunspot number analysis:
Input data file (acquired from National Geophysical Data Center (http://web.ngdc.noaa.gov/stp/SOLAR/solar.html).
(Save it to the same directory that you used for the executable program)
Input parameters (Save it to the same directory that you used for the executable program)

FUTURE PLANS
1. After a short testing period, the open code will be given publicly.
2. Refinement to the algorithmic procedures to get the program more efficient.
3. Future plans include a Linux development, so any help will be appreciated!
4. Of course, a GUI!!

Contact: stsant@phys.uoa.gr