Finding the mean Z score in the data set

AFNI Message Board
1

Hello AFNI experts,

I have a co-activation map with voxels that have different Z-score values. All I want to do is find the mean Z-score within that co-activation map. So, just a single number printed.

I have been investigating 3dcalc, 3dMean, and 3dTstat, but I don’t seem to be getting what I want.

I am sure there is an easy way to get this statistic but I am drawing a blank!

Thanks!

Emily

2

I believe the command 3dBrickStat is what you’re looking for!

3dBrickStat -mean ${path_to_Z_score_map}

This command also has options for voxels to include/exclude in the mean calculation (in case you want to exclude true 0s, NaNs, etc.).

Hope this helps!

3

3dBrickStat can take a mask dataset or a non-zero option. Also consider 3dmaskave for a single mask and 3dROIstats for a multi-valued ROI mask dataset like an atlas to apply against your dataset.