Relationship between node indexes and node spatial location of standard surface


What is the relationship between node indexes and node spatial location of standard surface? The picture from AFNI handouts shows that different part of the cortex take different index range? Then what’s the index-location relationship within these parts?

How to list node indexes in spatial order, for example, from anterior to posterior of the whole brain or brain lobe?

Thank you very much!

There are at least a few ways to output the coordinates of the nodes of a surface. First, the suma GUI shows them as you right click on the surface, but that gets tedious if you want more than a few. If you want all the coordinates, then try one of these:

SurfaceMetrics -i cubo.gii -coords (the output here, coords.coord.1D.dset, can color the datasets in suma as above using the first column - node index)
SurfMeasures -spec ./tmp_suma/cubo.spec -surf_A cubo -out_1D testout.1D -func coord_A
Convert the surface to an ascii text format like .asc or .ply, then view the file itself
gifti_tool -infile cubo.gii -write_asc cubo.asc
ConvertSurface -i ./tmp_suma/cubo.ply -o cubo2.asc

The coordinates here either use RAI or LPI coordinate order.

Hi Daniel,

Thank you for your pretty detailed answer.