GLT syntax error

Hi AFNI Gurus,

This might be a very simple fix, I have used similar GLT coding for 3dMVM before so seeing errors because now is quite perplexing.

** Error:
Failed at GLT No. 1! Make sure that the model or GLT specification syntax is correct.
Warning message:
In summary.Anova.mlm(object$Anova, multivariate = FALSE) :
Singular error SSP matrix:

-gltLabel 1 F-B -gltCode 1 ‘Scan : 1F -1B’
Subj Intervention Scan R3M R6M R12M InputFile
003 MI B 2 1 2 stats.003-1_REML+tlrc[25] \

Any help would be much appreciated.


Ben, could you share the first few lines of your 3dMVM script?

3dMVM -prefix 3dMVM_cond_scan -jobs 4
-bsVars “Intervention+R3M+R6M+R12M”
-wsVars “Scan”
-qVars “R3M,R6M,R12M”
-qVarCenters ‘3.648648649,4.36036036,3.315315315’
-mask scan1mask_resamp+tlrc
-SS_type 2
-num_glt 3
-gltLabel 1 F-B -gltCode 1 ‘Scan : 1F -1B’ \

How does the contingency table look like for Intervention and Scan? Does any “Intervention” group have a missing Scan level?

It is complete. It seems to run with no issues if I remove the GLTs, but I am noticing now that the F tests are coming back with 0s.