MATLAB: Code running very slow

loopoptimizationspeed

My code seems to run very slowly and I can't think of any way to make it faster. All my arrays have been preallocated. S is a large number of element (say 10000 element, for example). I know my code runs slowly because of the "for k=1:S" but i cant think of another way to perform this loop at a relatively fast speed. Can i please get help because it takes hours to run.
[M,~] = size(Sample2000_X);
[N,~] = size(Sample2000_Y);
[S,~] = size(Prediction_Point);
% Speed Preallocation
Distance = zeros(M,N);
Distance_Prediction = zeros(M,1);
for k=1:S
    for i=1:M
        for j=1:N
            Distance(i,j) = sqrt(power((Sample2000_X(i)-Sample2000_X(j)),2)+power((Sample2000_Y(i)-Sample2000_Y(j)),2));
        end
        Distance_Prediction(i,1) = sqrt(power((Prediction_Point(k,1)-Sample2000_X(i)),2)+power((Prediction_Point(k,2)-Sample2000_Y(i)),2));
    end
end

Best Answer

I realized the major problem was organization of my code. I was performing calculation in a loop where it was absolutely unnecessary. So i seperated the code in two blocks and it Works much faster.
for i=1:M
    for j=1:N
        Distance(i,j) = sqrt(power((Sample2000_X(i)-Sample2000_X(j)),2)+power((Sample2000_Y(i)-Sample2000_Y(j)),2));
    end
end
for k=1:S
    for i=1:M
    Distance_Prediction(i,1) = sqrt(power((Prediction_Point(k,1)-Sample2000_X(i)),2)+power((Prediction_Point(k,2)-Sample2000_Y(i)),2));
    end
end
Thanks to the community for the help.
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