Hi Gang and Rick,

Gang, thank you. Your solution for AFNI worked fine. I totally forgot that it is possible to select columns with 1dcat. So what your approach with AFNI does is the following:
1. 3dmaskdump: Extraction of all voxels from all subjects into one .1D file. This file contains as many columns as subjects. Each column contains the voxels from one specific subject.
2. Transpose all columns into one single row. The result is one row that contains the voxels from all subjects.
3. Transpose the row into a column.

Rick, when using 3dmaskdump per subject, the output was one file per subject that contains one column with thousands of voxels (one voxel per row). In this case, I already used 1dcat in order to "cat" the single columns together into a new file. Of course, the result was a new file that contains as many columns as subjects, while I wanted to add "one column after another" so that the number of columns (=1) remains stable (instead of having as many columns as there are subjects). I then thought that it is probably impossible to achieve my aim in AFNI and created this topic.
However, as stated above, I totally forgot about the single column selection option via 1dcat and the idea to transpose (File1'[0]'\', ...).

Happy new year.



Edited 1 time(s). Last edit at 01/01/2022 02:26PM by Philipp.