Hi professor, Thanks for your reply. When I perform the main effect of dignosis, is the following matrix I used correct? 0.25 0.25 0.25 0.25 -0.25 -0.25 -0.25 -0.25 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 (I think it regressed out the effect of genotype and gender, that is it takes the genotype as a covariable)
Or I should create another fsgd file, that has 4 classes: AF, AM, BF, BM. And I can use the matrix (0.5 0.5 -0.5 -0.5 0 0 0 0 0 0 0 0) to perform the main effect of diagnosis. Which one of two mentioned matrix is right?
Thanks a lot.
Best wishes
Meng
That is the correct matrix to use. You can create a new FSGD file (and the second matrix would be correct for it), but you do not have to. It will save you a few degrees of freedom. doug
On 09/07/2012 05:49 AM, Meng Li wrote:
Hi professor, Thanks for your reply. When I perform the main effect of dignosis, is the following matrix I used correct? 0.25 0.25 0.25 0.25 -0.25 -0.25 -0.25 -0.25 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 (I think it regressed out the effect of genotype and gender, that is it takes the genotype as a covariable)
Or I should create another fsgd file, that has 4 classes: AF, AM, BF, BM. And I can use the matrix (0.5 0.5 -0.5 -0.5 0 0 0 0 0 0 0 0) to perform the main effect of diagnosis. Which one of two mentioned matrix is right? Thanks a lot. Best wishes Meng
freesurfer@nmr.mgh.harvard.edu
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Douglas N Greve -
Meng Li