How to calculate centroid of a number or a group of numbers?

I am in meed of implementing Fast scanning algorithm, so the first step is that i need to group the pixels into clusters. So when comparing a new pixel with the previously grouped pixel(also called cluster) i need to find the centroid of the previously grouped pixel. So what should I do? Whether I need to implement this in a formula, if yes notify me with the formula or are there some other techniques to determine centroid?

Thanks in advance.

Answer 1

[Matt J]

There are lots of clustering algorithms on the FEX

http://www.mathworks.com/matlabcentral/fileexchange/index?utf8=%E2%9C%93&term=cluster