Another thing to try is to use the 3dclust program, which will print out a report of the clusters it finds (using the same algorithm as "3dmerge -1clust"). You can use the coordinates in the 3dclust report as input to the "Jump to (xyz)" popup chooser (right-click in an image viewer window to get this), and then you can see where the algorithm "thinks" the clusters are.
Program 3dinfo can be used to print out in a readable format the info in the .HEAD file - this will contain voxel dimensions, etc., which are essential values for doing clustering and other processing.
I don't always answer postings rapidly, parttly because I hope other folks will (thanks, Jim!), and partly because I have so much to do. For example, this week we ran into a problem here and at UCSD with the AFNI realtime plugin. And the ongoing saga of SUMA development continues, with AFNI and data handling infrastructure changes required to occur in parallel.
bob cox
