You can run with just the design matrix, but you won't be able to use the cool fsgdf stuff in tksurfer (Load->FSGDF). The fsgdf is a way to specify how to build the des mtx. The fsgdf keeps track of what the regressors mean (eg, Age, Class, IQ, etc). When you save the preprocessed data with --y, you'll see that there will be an fsgdf file saved with it. Load this in tksurfer, click on a point, and you will be able to make a scatter plot of, say, thickness vs age, with each class (eg, Male, Female) having a different color dot in the scatter plot. When you mouse-over the dot, it tells you the subject name. Click on a new point and you'll see the scatter plot for that point. If you use --xmat, you can save the design matrix (in matlab-4 format).
doug
On Tue, 21 Jun 2005, Fornito, Alexander wrote:
Hi,
I was seeking some clarification re: the relationship between the fsgdf and design matrix file for use with mris_glm. It seems to me that the two contain very similar info, the examples in the -help don't use the fsdf at all. Is it necessary to create one, or can you just run an analysis with the desmtx?
Thanks,
Alex
Alexander Fornito
M.psych (Clin. Neuro.)/PhD candidate
Melbourne Neuropsychiatry Centre and Department of Psychology
The University of Melbourne
alexander.fornito@wh.org.au