multiple grouping octave and layers

Hey all, i want to ask how to grouping this data by octave (first column) and layer (second column), is there some way to do this? i thought it must be used groupcounts, i was tried, but still got an error. After grouping i must be sorted by the number. so i could know which minor of that group then proceed it first using kmeans(12) by at least 2 value every group. But if there is group that have less than 2, we skipped it.

1	1	159	92
1	1	111	43
1	1	111	64
1	1	119	56
1	1	131	113
1	2	192	121
1	2	192	104
1	2	203	63
2	2	147	84
2	2	150	73
2	2	166	31
2	2	167	70
2	2	171	70
2	2	181	32
2	2	183	80
2	2	185	85
3	1	200	18
3	1	134	63
3	2	110	31

groups would look like follows:

octave 3 and layer 2 = 1
octave 3 and layer 1 = 2
octave 1 and layer 2 = 3
octave 1 and layer 1 = 5
octave 2 and layer 2 = 8

result of kmeans must 12 point (i dont know how), so after using kmean at least like this below (number of group must be distributed)

octave 3 and layer 2 = 1
octave 3 and layer 1 = 2
octave 1 and layer 2 = 3
octave 1 and layer 1 = 3
octave 2 and layer 2 = 3

[Elder Winter]

Okay, i want answer my own question, perhaps its help someone out there.

i = 12;
%for each keypoints octave
    for octave = 1:size(keypointDescriptor, 1)
        %for each keypoints layer 
        for kptLayer = 1:size(keypointDescriptor,2)
            
            %checking in every pixel
            [rowKpt colKpt] = find(keypointDescriptor{octave,kptLayer} == 1);
            
            for keypoint = 1:size([rowKpt colKpt],1)
                
                cont = cont+1;
                %storing octave, layer, column and row each point
                kMeansStack(cont) = struct('octave',octave,'kptLayer',kptLayer, ...
                                            'kptX',colKpt(keypoint),'kptY',rowKpt(keypoint));
                %take value from field
                oct = extractfield(kMeansStack(cont),'octave');
                lay = extractfield(kMeansStack(cont),'kptLayer');
                
                %checking, is the value is exist
                if octave == oct && kptLayer == lay
                    %if the value exist, it will count how many of them
                    iKpt(octave,kptLayer) = iKpt(octave,kptLayer)+1;
                end
            end
           
           %storing the result of each octave and layer
           Sorting(counter,1)=iKpt(octave,kptLayer); %result of counting
           Sorting(counter,2)=octave; %which octave they are
           Sorting(counter,3)=kptLayer; %which layer they are
           counter=counter+1;
        end
    end
    
    Sorting = sortrows(Sorting); %sorting row 1, from the minor one to the major
    
    %because cant bring struct to if condition, so i make new variable to
    %take value from field
    indexStack(:,1) = extractfield(kMeansStack,'octave');
    indexStack(:,2) = extractfield(kMeansStack,'kptLayer');
    indexStack(:,3) = extractfield(kMeansStack,'kptX');
    indexStack(:,4) = extractfield(kMeansStack,'kptY');
    
    %here is checking of each octave and layer and change it
    %the result must be 32 point for all octave and layer
    for counter = 1:size(Sorting,1)
        if Sorting(counter,1) < 3 %the main checking, checking is the value less than 3
            numKpt = numKpt - Sorting(counter,1); %if less than 3, minus the numKpt
            
        elseif Sorting(counter,1) >= 3 %if the point more than 3, it'll procced
            j = numKpt / (size(Sorting,1)-(counter-1)); %count the rest point for each octave and layer
            j = round(j);
            if Sorting(counter,1) < j %to check if the numbers is fit
                numKpt = numKpt - Sorting(counter,1);
            else
                Sorting(counter,1) = j;
                numKpt = numKpt - Sorting(counter,1);
            end
        end
        j = numKpt;
    end
    
    %exist 
    for cont = 1:size(indexStack,1)
        for counter = 1:size(Sorting,1)
    %        %find(keypointDescriptor{octave,kptLayer} == 1)
            if indexStack(cont,1) == Sorting(counter,2) && indexStack(cont,2) == Sorting(counter,3)
                disp([num2str(indexStack(cont,1)) ' & ' num2str(indexStack(cont,2)) ' = ' ...
                    num2str(Sorting(counter,2)) ' & ' num2str(Sorting(counter,3))]);
                X(cont,1) = indexStack(cont,3);
                X(cont,2) = indexStack(cont,4);
                if cont == size(indexStack,1) || ...
                    indexStack(cont,1) == Sorting(counter,2) && indexStack(cont+1,2) ~= Sorting(counter,3) || ...
                    indexStack(cont+1,1) ~= Sorting(counter,2)  && indexStack(cont,2) == Sorting(counter,3)
                    [ ~, C] = kmeans(X,Sorting(counter,1));
                    %disp(['cont = ' num2str(cont) ' & size(idx) = ' num2str(size(idx,1))]);
                    %disp(['cont = ' num2str(counter) ' & size(idx) = ' num2str(size(Sorting,1))]);
                    %disp (C);
                    storeKmeans{:} = C;
                    %resKMeans{:} = [ C ];
                end
            end
        end
    end

Please give me some suggest if there's something wrong in my code, thanks

[Image Analyst]

I didn't see where i was initialized. Anyway, we recommend against using i as an index or loop iterator/counter since it can also be used as the imaginary variable when using complex numbers. I have no idea what i and j even are so you should probably use a more descriptive variable name. Same comment for X, idx, and C -- use more descriptive names. It looks like C will get overwritten on each iteration and it doesn't look like you even do anything with it.

[Elder Winter]

Ohh sorry, i was initialized 'i' in my code but didn't copy it in this code. I make 'i' as how many kpt i want in this case 'i = 12'. So 'i' minus by how many kpt in those octave and layer, as i said before each octave and layer at least have 2 kpt. If not, it will take from other octave and layer. At the end i get my kpt as much as i want. 'j' just giving hand to 'i', then but I can't find names that is suitable for the descriptive names. But i will try to find some.

I was try store it by using this code

storeKmeans{counter,1} = indexStack(cont,1);
storeKmeans{counter,2} = indexStack(cont,2);
storeKmeans{counter,3} = C(keypoint,1);
storeKmeans{counter,4} = C(keypoint,2);

It works, but could i make it to one line code?