Re: [OctDev] [PKG] lssa

[Benjamin Lewis]

Le 2012-10-03 à 05:41, JuanPi <address@hidden> a écrit :

> Hi there,
> 
> I am exploring the lssa package, looks really handy. however I am
> finding difficult to understand the use.
> 
> I started testing lsreal and the last three input arguments are a
> little puzzling ( MAXFREQ, NUMCOEFF, NUMOCTAVES).
> Questions:
> 
> - Can't this arguments be estimated form the data by default and given
> as optional in case the user wants some specifics?
> - Is there an example of use of the function? A demo would be very very handy.
> - The doc string should contain a minimum explanation of what is
> maxfreq (at least in what units should be given (rad/s? Hz? normalized
> as in butter?), numcoef (i expected the result to be this length, but
> octave I was wrong), numoctaves.
> 
> If I get the grip of these functions I can help writing demos.
> 
> Thank you very much for your support.
> 

Hey;

Thank you for trying out lssa. Some background on the functions is in order to 
explain the arguments you're wondering about, I think:

The ls* functions in the lssa package implement the Lomb-Scargle transform, 
which is a non-invertible transform which tests independent frequencies against 
the provided data set; its operations expect radian input, but beyond that, the 
MAXFREQ term is essentially rad/(pick the unit that matches from your data). 
The transform (in the case of lsreal and lscomplex) operates over NUMOCTAVES 
octaves, testing NUMCOEFFS evenly-spaced frequencies per octave. I've got a 
demo in the works on Octave-Forge, I'll put some time into expanding it, and 
once it's ready I'll prepare another release of the package together (although 
it does feature an application of the functions, it doesn't use all of them 
yet, I don't think.)

In response to the first question, then, I don't think the arguments can really 
be estimated without possibly running the function first; I'd be happy to get 
some input on that, though.

Thanks for your feedback on the package!

Ben