Question

I would like to know how can I get certain inputs and put them in more than one row in the cell array …
I basically want an array that updates one input per row in ever loop.
The loop is looped 30 times, so I want to have 30 rows and 2 columns ( x and y columns)

I have this code :

For N=1:30
    .
    .
    .
    Binary = bwlabel(blacknwhite);
    s = regionprops(Binary,'centroid');
    centroids = cat(1, s.Centroid);
    hold(imgca,'on')
    plot(imgca,centroids(1,1), centroids(1,2),'r*')
    .
    .
    .
    end

I dont think this does what I want … only the first row is updated in my loop ..
So how can I create this cell array ?

If you want more info please tell me and I will update it right away.

Thanks !

Answer 1

I assume that you want to store the centroids. In this case, you should use centroids(N,:)=cat.... Also, as @High Performance Mark says, you should preallocate the array.

centroids = zeros(30,2); %# this assumes 1 centroid per image. 
For N=1:30
    .
    .
    .
    Binary = bwlabel(blacknwhite);
    s = regionprops(Binary,'centroid');
    centroids(N,:) = cat(1, s.Centroid);
    hold(imgca,'on')
    plot(imgca,centroids(N,1), centroids(N,2),'r*')
    .
    .
    .
end