Hi Ye, don't select the same factor as nuisance and covariate. It will
result in an error for sure. The difference between a covariate and a
"nuisance" factor is purely conceptual. By calling something a nuisance
you tell QDEC not to create a contrast related to it.
doug

On 08/13/2013 02:09 AM, ye tian wrote:
> Dear Freesurfers,
> I have a question concerning the "nuisance factors" in the qdec
> dialogue. Suppose I have two independent variables x1 (discrete) and
> x2 (continuous), and only one observable y. I choose "Discrete (Fixed
> factor) = x1", "Continuous (covariate) = x2".
> If I further chose "Nuisance factor = x2", does that imply that
> 1) my contrast matrix is (0 1)
> 2) null hypothesis: Y is independent of x2
> Thank you very much!
> Sincerely,
> Ye
>
>

> _______________________________________________
> Freesurfer mailing list
> Freesurfer@nmr.mgh.harvard.edu
> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer

--
Douglas N. Greve, Ph.D.
MGH-NMR Center
greve@nmr.mgh.harvard.edu
Phone Number: 617-724-2358
Fax: 617-726-7422

Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting
FileDrop: https://gate.nmr.mgh.harvard.edu/filedrop2
www.nmr.mgh.harvard.edu/facility/filedrop/index.html
Outgoing: ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/

_______________________________________________
Freesurfer mailing list
Freesurfer@nmr.mgh.harvard.edu
https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer


The information in this e-mail is intended only for the person to whom it is
addressed. If you believe this e-mail was sent to you in error and the e-mail
contains patient information, please contact the Partners Compliance HelpLine at
http://www.partners.org/complianceline . If the e-mail was sent to you in error
but does not contain patient information, please contact the sender and properly
dispose of the e-mail.