Hi Aral,
The average correlation across the brain could
be done basically the way afni_proc.py computes
the single-value global correlation (GCOR). If the
data is scaled to be unit vectors (sum squares = 1),
then correlations are dot products. And the average
dot product of one vector with many others is the
dot product of it with the average. So...
3dTnorm -prefix unit.data DATA+tlrc
3dmaskave -quiet -mask BRAIN_MASK+tlrc unit.data+tlrc > brain.mean.1D
3dTcorr1D -prefix mean.brain.corr unit.data+tlrc brain.mean.1D
- rick
Edited 1 time(s). Last edit at 08/20/2014 12:44PM by rick reynolds.