afni.nimh.nih.gov

Thanks for your quick response, Daniel.

I think I'm doing something wrong, because my dset file is a bunch of random characters (see screenshot attached) and 3dBrick Stat is giving me the following error:
(base) ashamehta-mbp:mri_ODP663 ashamehta$ 3dBrickStat -sum test.niml.dset'[1]'
** ERROR: selector index 1 is out of range 0..0
** ERROR: bad sub-brick selector [1]
** FATAL ERROR: Can't open dataset 'test.niml.dset[1]'
** Program compile date = Feb 26 2020

Here are the steps I took:
1) I converted the ROI to a dataset using:
ROI2dataset -prefix test -pad_to_node 139750 -input func_motor/stats_motor_ODP663_2020-02-27/test.niml.roi
I used the Surface Properties section of the Object Controller to find the number of nodes.

2) When using SurfMeasures to calculate area, I received the following error:

(base) ashamehta-mbp:mri_ODP663 ashamehta$ SurfMeasures -info_area -func n_area_A -spec struct/freesurfer_ODP663/SUMA/ODP663_both.spec -surf_A struct/freesurfer_ODP663/SUMA/lh.smoothwm.gii -cmask '-a test.niml.dset -expr step(a)' -out test_surf_measure.niml.dset
** cmask and node list lengths differ (139751, 139750)

I then subtracted 1 from the number of nodes and tried:
ROI2dataset -prefix test -pad_to_node 139749 -input func_motor/stats_motor_ODP663_2020-02-27/test.niml.roi

This produced a dset file that I found the area of using SurfMeasures:
(base) ashamehta-mbp:mri_ODP663 ashamehta$ SurfMeasures -info_area -func n_area_A -spec struct/freesurfer_ODP663/SUMA/ODP663_both.spec -surf_A struct/freesurfer_ODP663/SUMA/lh.smoothwm.gii -cmask '-a test.niml.dset -expr step(a)' -out test_surf_measure.niml.dset
----------------------------------------------------------
-- total area 0 = 15.4
-- from cmask, nodes skipped = 139726

3) In case this is helpful, the output of 3dBrickStat without the selector index is:
(base) ashamehta-mbp:mri_ODP663 ashamehta$ 3dBrickStat -sum test.niml.dset
24

Do you spot the issue?
Thanks.