Compute average size of 2 regions in a matrix

Hi all,

I would like to normalze a structural connectivity matrix (360 x 360) containing the number of streamlines between any two regions by the (average/sum) size of the respective two regions.

I do have information about the size of each brain regions (360) but what I would like to do is average the size of two regions and save that number in a Matrix (360 x 360) so that each node contains information about the average size of the two regions.

Any help would be appreciated, thanks!!

[Matt J]

I recommend providing a scaled-down example of the desired operation, say, on a 5x5 connectivity matrix.

[Johanna Popp]

You're right, that could be helpful. Lets say I have a vector of 5 numbers [2 4 8 9 12]. I want to create a matrix with the size 5*5 containing the average of each of the respective pairs of numbers in the corresponding field of the matrix. In this case it would be

[2 3 5 5.5 7; 3 4 6 6.5 8; 5 6 8 8.5 10; 5.5 6.5 8.5 9 10.5; 7 8 10 10.5]

Instead of the 5*1 vector that I provided here as a example, I am working with a vector containing 360 numbers.

I hope this helps, thank you!

[Image Analyst]

Isn't this just a duplicate of your other question?

https://www.mathworks.com/matlabcentral/answers/1620875-create-a-matrix-of-average-values-from-a-vector#question_1620875

Answer 1

[Pranjal Kaura]

Hey Johanna,

Could you please share a snippet of the data file? Further providing an example on that data would also be helpful.

[Johanna Popp]

Hi Pranjal,

please refer to my response on the comment above for an example! Thank you for your help!