Hi, Zixun-
OK, thanks for sharing the data.
A couple things to note: The EPI dataset has a wide range of values, from -637911 to 314724, but it also includes supertiny, nonzero values, of order 10**-28 and 10**-31. The mask that is being used with it also doesn't seem to perfectly fit the data.
The large range of values isn't really a problem, but I am surprised to see it. The source of the calfun errors is having entire time series that have supertiny nonzero values---the mask doesn't remove those. Also, automasking didn't work well with this dset because it has a somewhat filamentary spatial structure. So, to generate a mask where time series were non-zero and non-supertiny, I did the following:
3dcalc \
-a DSET_EPI'[0]' \
-expr 'step(a-0.001)+step(-a-0.001)' \
-prefix mask_estimate2.nii.gz \
-overwrite
(Note that you could adjust the windowing around zero, which is masking out anything that has magnitude <0.001.)
After doing that, I reran your 3dFWHMx command:
3dFWHMx \
-detrend 2 \
-mask mask_estimate2.nii.gz \
-dset sub-012_task-motor_acq-ME5_negDelta_R2_star.nii.gz \
-acf sub-012_task-motor_negDelta_R2_star >> output3dFWHMx
... and there were no calfun errors. Therefore, those were a result of the supertiny nonzero values, or quasi-zero time series, being present in the non-masked region.
The resulting ACF image looked pretty reasonable, I would say. Though, I will note again the caveat that this program was designed for working on residual datasets.
--pt
