Hi Gang,
I have a question regarding how to use 3dttest or 3dttest++.

Each participant had a dataset with classification accuracy after I finished searchlight, but now I need to select voxels that their classification accuracy significantly higher than the chanve level (0.5) from every participant. I want to do the analysis of each participant, not a group analysis.

My script and Warning Message with 3dttest++:

3dttest++ -prefix FT_TF
-singletonA ‘0.5’
-setB ‘searchlight24bg+tlrc’

++3dttest++: AFNI version=AFNI_18.3.15
++ -singletonA testing against fixed value=0.5

  • ==> option -BminusA is automatically turned on
    ++ option -setB:: processing as SHORT from(all values are datasets)
    ** FATAL ERROR: option -set B(short form): need at least 2 datasets or sub-bricks.

or 3dttest -prefix FT_TF
-base1 ‘0.5’
-set2 ‘searchlight24bg+tlrc’
** FATAL ERROR: option -set 2 doesn’t have eough datasets.

Thanks a lot in advance.



3dttest and 3dttest++ are intended to be used in scenarios where there are multiple samples such as group analysis. There’s only one sample in your case, which is why they would not work.