Hi,
On Fri, Jan 05, 2007 at 06:30:44PM +0000, Clare Kelly wrote:
> Hi all,
>
> I apologise if this is a really basic question but I can't seem to find the answer I'm looking for in the
> archive.
>
> I want to calculate the residuals for a particular model that included 4 task regressors plus their
> temporal derivatives, 8 nuisance regressors, and 6 motion parameters, as I want to compare the
> residuals between different models with different numbers of regressors.
>
> I understand that each varcope gives me the error related to that particular EV, but I'm not clear on
> how I combine them - I have looked at section 14.5 of the Jezzard et al. book but I still don't know
> what to do.
FEAT can output the residuals for you (no need to calculate anything).
In fact it always stores them to disk, but deletes them at the end of
the analysis. Just look at the end of you design.fsf file and you'll
see:
# Delete GLM residuals?
set fmri(cleanup_residuals_yn) 1
Change this default into:
# Delete GLM residuals?
set fmri(cleanup_residuals_yn) 0
and you'll find a res4d.nii.gz (or whatever suffix) in the stats
directory when Feat is finished.
HTH.
Cheers,
Michael
--
GPG key: 1024D/3144BE0F Michael Hanke
http://apsy.gse.uni-magdeburg.de/hanke
ICQ: 48230050
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