[SciPy-Dev] Dev suggestion: expand signal.slepian functions (Virginia Frey)

[Virginia Frey]

Hey,

Thanks, I didn't see that. This is actually exactly what I wanted, so 
that's great! In my work I normalise the DPSS by their area because I 
need them all to have the same integrated spectral weight. I'll have 
another look at the multitaper technique and maybe I'll come across a 
different form of modulation there, in which case I'd let you know.

Thanks again,

Virginia


On 08/04/18 23:29, 3ukip0s02 at sneakemail.com wrote:
> On Sun, 8 Apr 2018 08:14:47 +1000, Virginia Frey wrote:
>
>     The current implementation of Slepians in scipy's signal module only
>     offers the zeroth order, so it is not possible to use for e.g. the
>     multitaper spectral analysis. In addition to that, because of the way
>     the eigensystem is solved, it breaks with a MemoryError when using
>     high
>     numbers of points (i.e. a few thousand). The request for high
>     numbers of
>     points is not unreasonable: people do take long time-traces and
>     the FFT
>     makes it possible to compute Fourier transforms on those.
>
>
> In SciPy 1.1.0, windows.slepian will be deprecated and replaced by 
> windows.dpss :
>
> https://scipy.github.io/devdocs/generated/scipy.signal.windows.dpss.html 
> <https://scipy.github.io/devdocs/generated/scipy.signal.windows.dpss.html>
> https://github.com/scipy/scipy/pull/7802 
> <https://github.com/scipy/scipy/pull/7802>
> https://github.com/scipy/scipy/issues/4354 
> <https://github.com/scipy/scipy/issues/4354>
>
> Does that do what you want?
>
>     I have working code for this, which is based on the implementation
>     suggested in [5] but is in pure Python.
>
>
> Aren't there copyright/license issues with using code from Numerical 
> Recipes?
>
>     Once we have the full set of Slepians available, from there we (or I)
>     could also implement the multitaper spectral analysis technique
>
>
> That would be useful!
>
>     So, what do you guys think of my proposal? If you like it, please
>     advise
>     me on how to proceed as this is the first time I'm planning to
>     contribute. From what I took of the web page, I'll start by
>     downloading
>     the repo - and then should I make a new branch? I'm also happy to send
>     some code through via email for your review first.
>
>
> Can you read through https://github.com/scipy/scipy/pull/7802 
> <https://github.com/scipy/scipy/pull/7802> and comment if you see a 
> problem with it, or it doesn't do all that you would want it to do?
>
> Also we were a little confused about how best to normalize the 
> amplitude of the functions.  In your work, do you use the L2 norm?
>
>
>
> _______________________________________________
> SciPy-Dev mailing list
> SciPy-Dev at python.org
> https://mail.python.org/mailman/listinfo/scipy-dev

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/scipy-dev/attachments/20180410/b29cbe41/attachment.html>