[pymvpa] Searchlight question

[Michael Hanke]

Hey,

On Thu, Jun 10, 2010 at 09:48:44AM -0400, Per B. Sederberg wrote:
> Hi Folks:
> 
> I'm gearing up to do a searchlight analysis (with the bleeding edge
> development code) and, when reading through the searchlight.py example
> (and making some minor corrections to the text), I learned how
> center_ids work.  This is an awesome feature, but I wonder if it
> should be attached to the searchlight run call instead of to the init
> call.
> 
> Specifically, we currently set the center_ids like this:
> 
> sl = sphere_searchlight(cv, radius=radius, space='voxel_indices',
>                              center_ids=center_ids,
>                              postproc=mean_sample())
> 
> But might it be better to keep the searchlight instance divorced from
> the dataset and pass it in at runtime:
> 
> sl_map = sl(ds, center_ids=center_ids)
> 
> 
> I have not looked closely at the underlying code, so I don't know if
> there is a specific reason it works as it does.  Any thoughts?

We cannot attach the center_ids to the __call__(). All objects in PyMVPA 0.5
(when it will be finally released) will take a dataset on call() and do
something useful. A dataset alone has to be sufficient, since they also
will return a dataset when called and that way can be combined into
arbitrary processing chains.

Hope that explains,


Michael

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GPG key:  1024D/3144BE0F Michael Hanke
http://mih.voxindeserto.de