# Vertex number in MNE STC

**URL:** <https://mne.discourse.group/t/vertex-number-in-mne-stc/279>\
**Category:** Mailing List Archive (read-only)\
**Tags:** list-archive\
**Created:** [December 17, 2010, 10:44am UTC](https://mne.discourse.group/t/vertex-number-in-mne-stc/279 "2010-12-17T10:44:48Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [December 17, 2010, 10:44am UTC](https://mne.discourse.group/t/vertex-number-in-mne-stc/279/1 "2010-12-17T10:44:48Z")

</div>

Dear MNE group,

I am trying to understand why the vertex number shown in the .vertices field in the STC file are placed in a very specific order. Does anyone know what this order represents? My impress is that it may reflect the adjacent information, but I can't be sure. If anyone know, please do help me because I would like to use this information.

Many thanks,

Li Su

-------------- next part --------------  
An HTML attachment was scrubbed...  
URL: [http://mail.nmr.mgh.harvard.edu/pipermail/mne\_analysis/attachments/20101217/64b9a842/attachment.html](http://mail.nmr.mgh.harvard.edu/pipermail/mne_analysis/attachments/20101217/64b9a842/attachment.html)

---

<div class="post-metadata">

**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [December 17, 2010, 1:13pm UTC](https://mne.discourse.group/t/vertex-number-in-mne-stc/279/2 "2010-12-17T13:13:49Z")

</div>

Hi Li,

The vertex numbers correspond the the initial tesellation of the surfaces  
that Freesurfer does (which you subsample to make your source space).

However, in the process of making topological correction to the surfaces,  
Freesurfer adds/removes vertices as needed. Because of this there is no  
simple relationship that I am aware of between the vertex number and  
adjacency.

The documentation for 'mne\_add\_patch\_info' and for the 'surf' MATLAB  
structure might be helpful if you are interested in using topological  
information for your purposes.

Regards,  
Hari