euclidean distances (fMRI)

Hello,

I am working with functional MRI. I have some groups of foci from different experiments. I would greatly appreciate if someone can give any hint on how to measure the euclidean distances between a seed voxel and a the individual foci the a databased experiments (groups of foci/coordinates).

Thank you very much

Lorena

[Sean de Wolski]

http://en.wikipedia.org/wiki/Euclidean_distance

Perhaps you could provide us with a little more information about your data.

[Lorena]

I would greatly appreciate if someone can give any hint on how to measure the euclidean distances between a seed voxel and the individual foci of all databased experiments (groups of foci/coordinates).

[Lorena]

Hello,

Thanks for replying. I have some individual seed voxels and a set of experiments, I want to measure the euclidean distances between each of those seeds and the groups of foci reported from those experiments to know which coordinates reported closest activation to my seed voxel.

Thank you very much for helping me on this matter

Lorena

Answer 1

[Sean de Wolski]

%sample 2d data
seed = [11 30];
others = round(rand(10,2)*50);

%Engine
dists = sqrt(sum(bsxfun(@minus,seed,others).^2,2));

Add a third column for the third dimension.

[Lorena]

Hello Sean,

I will give it a try

Thank you so much :-)

Lorena