afni.nimh.nih.gov

I have one volume with 20 slices of data. I would like to calculate the mean and standard deviation of each pixel and save it a volume dataset.
I tried implementing this following in 3dcalc. However could not implement the expression. Is there a way we could do this. Any help is appreicated.

The command i tried was
3dcalc -a test+orig -expr 'sqrt (sum( a - 14)^2 / (1500))' -prefix std

I know we cannot use sum and power 2 in the expr, but thats what I would like to implement.

Thanks
Partha