2x2 ANOVA, tp2-tp1 is not an option for study design - Freesurfer

1 Dec 2021


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Hi list,
I have two groups undergoing two different treatments: one's placebo (n=12), one's drug (n=12). Two timepoints, at baseline (T1, no treatment) and at treatment (T2). 2x2 ANOVA, repeted measures has been applied by following the guidlines and mailing list.
to compute tp2-tp1, as reported in the fsgd example, is not an option for study design because we aiming to assess the interaction time-x-group.treatment
Please chech the design matrix, the command line produces an error.
GroupDescriptorFile 1
Title 2x2_repeted_measures
Class Subject1
Class Subject2
Class Subject3
Class Subject4
Class Subject5
Class Subject6
Class Subject7
Class Subject8
Class Subject9
Class Subject10
Class Subject11
Class Subject12
Class Subject13
Class Subject14
Class Subject15
Class Subject16
Class Subject17
Class Subject18
Class Subject19
Class Subject20
Class Subject21
Class Subject22
Class Subject23
Class Subject24
Variables tp1-vs-tp2.drug tp1-vs-tp2.plb
Input CODE01_tp1 Subject1 1 0
Input CODE02_tp1 Subject2 1 0
Input CODE03_tp1 Subject3 1 0
Input CODE05_tp1 Subject4 1 0
Input CODE06_tp1 Subject5 0 1
Input CODE07_tp1 Subject6 0 1
Input CODE09_tp1 Subject7 0 1
Input CODE10_tp1 Subject8 1 0
Input CODE11_tp1 Subject9 1 0
Input CODE12_tp1 Subject10 0 1
Input CODE13_tp1 Subject11 0 1
Input CODE14_tp1 Subject12 1 0
Input CODE15_tp1 Subject13 1 0
Input CODE16_tp1 Subject14 1 0
Input CODE17_tp1 Subject15 0 1
Input CODE18_tp1 Subject16 1 0
Input CODE19_tp1 Subject17 0 1
Input CODE20_tp1 Subject18 0 1
Input CODE21_tp1 Subject19 0 1
Input CODE22_tp1 Subject20 1 0
Input CODE23_tp1 Subject21 0 1
Input CODE24_tp1 Subject22 0 1
Input CODE25_tp1 Subject23 1 0
Input CODE26_tp1 Subject24 0 1
Input CODE01_tp2 Subject1 -1 0
Input CODE02_tp2 Subject2 -1 0  
Input CODE03_tp2 Subject3 -1 0  
Input CODE05_tp2 Subject4 -1 0  
Input CODE06_tp2 Subject5 0 -1
Input CODE07_tp2 Subject6 0 -1
Input CODE09_tp2 Subject7 0 -1
Input CODE10_tp2 Subject8 -1 0  
Input CODE11_tp2 Subject9 -1 0  
Input CODE12_tp2 Subject10 0 -1
Input CODE13_tp2 Subject11 0 -1
Input CODE14_tp2 Subject12 -1 0
Input CODE15_tp2 Subject13 -1 0
Input CODE16_tp2 Subject14 -1 0
Input CODE17_tp2 Subject15 0 -1
Input CODE18_tp2 Subject16 -1 0
Input CODE19_tp2 Subject17 0 -1
Input CODE20_tp2 Subject18 0 -1
Input CODE21_tp2 Subject19 0 -1
Input CODE22_tp2 Subject20 -1 0
Input CODE23_tp2 Subject21 0 -1
Input CODE24_tp2 Subject22 0 -1
Input CODE25_tp2 Subject23 -1 0
Input CODE26_tp2 Subject24 0 -1
a) groupxtime.mtx 0 0 1 -1
b) tp1-vs-tp2.Mod.mtx 0 0 1 0
c) tp1-vs-tp2.Plb.mtx 0 0 0 -1
mri_glmfit --y ces.nii.gz --wls cesvar.nii.gz --surface fsaverage rh --glmdir repeted_measures.wls --nii.gz --fsgd Repeted_measure.fsgd --C Tp1-vs-Tp2.Mod.mtx --C Tp1-vs-Tp2.Plb.mtx --C groupxtime.mtx
ERROR: dimension mismatch between X and contrast Tp1-vs-Tp2.Mod.mtx       X has 72 cols, C has 4 cols