Re: [Freesurfer] Making a Patch

2022-01-04 Thread Douglas N. Greve
External Email - Use Caution Can you describe exactly what you are doing on a click-by-click basis? On 1/4/2022 9:55 AM, Alison McDonnell wrote: External Email - Use Caution When I click on the region to keep it says "please move cursor to a valid vertex" but I can see

Re: [Freesurfer] Making a Patch

2022-01-04 Thread Alison McDonnell
External Email - Use Caution When I click on the region to keep it says "please move cursor to a valid vertex" but I can see the blue mark on the region On Sun 2 Jan 2022, 21:13 Douglas N. Greve, wrote: > You have to make sure that you click in the region that you want to keep

Re: [Freesurfer] Making a Patch

2022-01-02 Thread Douglas N. Greve
You have to make sure that you click in the region that you want to keep (ie, you should be able to see the cursor in your region) On 12/20/2021 8:11 AM, Alison McDonnell wrote: External Email - Use Caution Hi Freesurfer, I am currently trying to make a patch to make a flat map. I ma

[Freesurfer] Making a Patch

2021-12-20 Thread Alison McDonnell
External Email - Use Caution Hi Freesurfer, I am currently trying to make a patch to make a flat map. I make the relaxation cuts and circular cut in midline region but then when I try to remove the circle it removes everything but. I can't work out why this is happening as I was

Re: [Freesurfer] Making a patch of area A

2005-03-09 Thread Rutvik Desai
Hello, You may prefer to write your own code for calculating the patch, but I thought I would just mention that this functionality is implemented in Caret (http://brainmap.wustl.edu/resources/caretnew.html). Caret can read FreeSurfer surfaces. It will calculate the distance of all nodes from a gi

Re: [Freesurfer] Making a patch of area A

2005-03-09 Thread Doug Greve
The sphere-based patch will change size and shape a little when you map it back to the folded surface due to metric distortion. So you could refine it some, eg, run your Dijstra algorithm on just the patch. I would not expect the distortion to make much of a difference, so it's probably not worth

Re: [Freesurfer] Making a patch of area A

2005-03-09 Thread Daniel Goldenholz
Hi Bruce Yes, I'm sorry I wasn't clear in my previous posting. I think that you and I are talking about the same thing... The surface distance along the sphere from my vertex point... let's call that arc length. So I want to have all freesurfer points which are less than or equal to an arc leng

Re: [Freesurfer] Making a patch of area A

2005-03-08 Thread Bruce Fischl
Hi Daniel, don't use Euclidean distance. Use the length of the great circle connecting each point to the central vertex on the ?h.sphere surface. Bruce On Tue, 8 Mar 2005, Daniel Goldenholz wrote: Doug I was thinking of trying something like that. If I took all vertices which are a radius M or

Re: [Freesurfer] Making a patch of area A

2005-03-08 Thread Daniel Goldenholz
Doug I was thinking of trying something like that. If I took all vertices which are a radius M or less from my centriod, aren't I basically done? (M is defined as the maximum euclidean distance between the centroid on the sphere and the ring of outer vertices. If my surface distance max is calle

Re: [Freesurfer] Making a patch of area A

2005-03-08 Thread Rudolph Pienaar
Hi Daniel - Well it seems to me that you're almost there already. A Dijkstra algorithm is the ideal engine to determine radial paths from a central node - I suspect you just need to tune the graph cost function to take the Euclidean distance between nodes (as opposed to the logical distance) in

Re: [Freesurfer] Making a patch of area A

2005-03-08 Thread Doug Greve
You might try starting off with the ?h.sphere. It's easy to parameterize these things on the sphere. The sphere, of course, has some metric distortion, but if the patch is small, it might not be to bad. Once you've identified the vertices in the patch (or maybe a slightly bigger patch), then you c

[Freesurfer] Making a patch of area A

2005-03-08 Thread Daniel Goldenholz
Hi. I have a graph theory question: I would like to make a definition of a particular patch of cortex, that has a centroid at position (x,y,z) and has a total area of A. I thought that this was going to be somewhat hard, but I soon learned that it is very hard. First, I found some code for the