[Freesurfer] Vertex index information for a sphere.reg file

Dear FreeSurfer,

Hi,

I have a label with vertex index, RAS and overlay values, and want to add spherical coordinates to them as presented in tksurfer.

I found following archives that are related to this question, but I couldn't find any vertex index (number) information in a sphere.reg file. (http://www.mail-archive.com/freesurfer@nmr.mgh.harvard.edu/msg00627.html)

I converted ?h.sphere.reg file into ?h.sphere.reg.asc using *mris_convert* command, and imported it to MATLAB using *read_asc.m* file (without face data). They had [x,y,z] coordinates in columns, but did not provide vertex index information.

I wonder if there is a way to read the vertex index from a sphere.reg file, or there are other methods that read both vertex index and spherical coordinates.

Thank you, Jihoon Oh