new functions

[Robert Oostenveld]

Dear fieldtrippers,

I have implemented three new functions that all relate to
SOURECANALYSIS, and are especially relevant to help reduce memory
requirements in randomization stats.

SOURCE2GRID should help you to remove all the unneccesary items from a
sourcestructure, so that you can use it in cfg.grid for sourceanalysis.

SOURCE2SPARSE removes all dipole locations from a source structure that
are outside teh head. Source strength at these locations is not
computed anyway, so it does not make the computation faster, but those
locations do take up memory. The reduced sourecspace (or precomputred
grid) can take ~2x up to 10x as less memory as the full sourcespace.

SOURCE2FULL is the opposite from source2sparse and it will add all
outside locations again, recreating the complete source volume that you
can plot, interpolate and export.

I hope that they are all bug free, but they have not yet been tested
extensively. Use with caution.

best regards,
Robert


PS the functions are available as usual in the FC Donders internal
/home/common/matlab/fieldtrip directory

----------------------------------------------------------------------
Robert Oostenveld, PhD
Center for Sensory-Motor Interaction (SMI)
Aalborg University, Denmark

and

F.C. Donders Centre for Cognitive Neuroimaging
University Nijmegen
P.O. Box 9101
NL-6500 AH Nijmegen
The Netherlands

Tel: +31 (0)24 3619695
Fax: +31 (0)24 3610989