[pymvpa] Connecitvity Hyperalignment and SeedQuerryEngine

[Yaroslav Halchenko]

On Fri, 12 Oct 2018, Vincent Taschereau-Dumouchel wrote:

> Hi everyone,

> First of, thanks a lot for sharing the connectivity hyperalignment code. You guys are doing awesome work.
> I am starting to play around with it and was wondering about 2 things:

> - Do you have an example of the arguments that needs to be provided? One of them is the SeedQueryEngine. I went through the code a little and I am having a hard time determining what this is exactly. 

seed_queryengines  are needed for figuring out neighborhood to average
for estimating connectivity to it.  I am not quite sure (CCing the
original author Swaroop and Feilong who might know better) why your
"main" queryengine could/shouldn't be used (the test uses the
same) if you are working in the same "domain" (e.g. in the volume for
both the searchlight and then the seeds).  If so, may be code could be
adjusted to avoid demanding specification of the seed_queryengines?

> - Also, can we use it not with surfaces but with typical volume data? I understand the problems associated with running a searchlight on volume data but I was just trying to take a quick peak at the function before processing surfaces and all.

AFAIK, due to all those "query engines" flexibility, it could be used in
a variety of scenarios:

- everything in the volume
- everything (projected) on the surface
- having surface guiding selection of the voxels in the volume


-- 
Yaroslav O. Halchenko
Center for Open Neuroscience     http://centerforopenneuroscience.org
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