One way is to create a surface overlay with the target vertex = 1 and other vertices 0 (mri_volsynth, use delta, works for surface overlays too). Then smooth by a certain FWHM (mri_surf2surf or mris_fwhm). This will create a circle. If you divide all vertices by the value of the vertex after smoothing and then threshold at 0.5, then you should have a circle of radius approximately FWHM/2.

On 11/08/2015 05:43 PM, dgw wrote:

The only code I am aware of for doing this is in mne-python.

hth d

On 11/8/15 5:36 PM, Reza Rajimehr wrote:

...

Hi,

I want to draw a circle around a vertex on the smoothwm or pial surface, with a particular radius (e.g. 10 mm), fill the circular region and save it as a label file, then repeat this for all the vertices on the surface. I need this for doing a searchlight analysis. Does anyone have a script/code for it?

I know that mris_pmake (using Dijkstra's algorithm) can be used for this purpose, but I don't know exactly how to make it to work in a script for drawing circular ROIs.

Thanks for any help!

Reza

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that will work too, but you can't control the radius like you can with my new solution :)

On 11/09/2015 04:22 PM, Reza Rajimehr wrote:

Thanks Doug! I also found another solution from you in this post: https://mail.nmr.mgh.harvard.edu/pipermail//freesurfer/2013-July/031726.html Reza One way is to create a surface overlay with the target vertex = 1 and other vertices 0 (mri_volsynth, use delta, works for surface overlays too). Then smooth by a certain FWHM (mri_surf2surf or mris_fwhm). This will create a circle. If you divide all vertices by the value of the vertex after smoothing and then threshold at 0.5, then you should have a circle of radius approximately FWHM/2.

On Sunday, November 8, 2015, Reza Rajimehr <rajimehr@gmail.com mailto:rajimehr@gmail.com> wrote:

Hi,

I want to draw a circle around a vertex on the smoothwm or pial
surface, with a particular radius (e.g. 10 mm), fill the circular
region and save it as a label file, then repeat this for all the
vertices on the surface. I need this for doing a searchlight
analysis. Does anyone have a script/code for it?

I know that mris_pmake (using Dijkstra's algorithm) can be used
for this purpose, but I don't know exactly how to make it to work
in a script for drawing circular ROIs.

Thanks for any help!

Reza

---

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