Hi

I'm trying to run 3dQwarp using multiple threads(N=2 versus N=6 in the following script lines). However, it seems that the warp fields calculated by 3dQwarp are not identical when I use different number of threads. This results in different afni_proc.py outputs for identical inputs but different number of threads( N=2 vs N=6). Here is what I run:

N=number_of_threads
export OMP_NUM_THREADS=$N
3dQwarp -plusminus -pmNAMES Rev For \
-pblur 0.05 0.05 -blur -1 -1 \
-noweight -minpatch 9 \
-source rm.blip.med.masked.rev+orig \
-base rm.blip.med.masked.fwd+orig \
-prefix thereadsNum/blip_warp_$N

blip_warp_For_WARP+orig is then different for N=2 vs N=6.

Anyone has an idea what is the problem/solution?

And this is the afni version I use:
Precompiled binary linux_ubuntu_16_64: Dec 22 2017 (Version AFNI_17.3.09)



The image below shows %difference between a volume warped using 2 and 6 threads. The difference is in the same order as warping two different volumes using equal number of threads.