MATLAB: Find the average of a vector with specific condition

datadatabasematrix array

I had A vector
   A=[1 0 0 2 3 2 3 5 0 0 0 0 1 2 1 0 0 0 0 3 4 0 0 0 0 0 0 1 2 3 2 0 0 0 0 2 0 0]
like this. Now I want a vector B having average of corresponding non-zero value, like
B(1)=average(A(1));
B(4)=average(A(4):A(8));
B(13)=average(A(13):A(15);
B(20)=average(A(20):A(21));
B(28)=average(A(28):A(31)) and so on .....rest values should be zeros.
hence
B=[1 0 0 3 0 0 0 0 0 0 0 0 1.33 0 0 0 0 0 0 3.5 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 2 0 0 ]

Best Answer

Credits to Guillaume for cleaning up my original code.
A=[1 0 0 2 3 2 3 5 0 0 0 0 1 2 1 0 0 0 0 3 4 0 0 0 0 0 0 1 2 3 2 0 0 0 0 2 0 0];
B=zeros(size(A));
bounds = find(diff([0, A, 0] ~= 0));
starts = bounds(1:2:end);
ends = bounds(2:2:end) - 1;
B(starts) = arrayfun(@(s, e) mean(A(s:e)), starts, ends);
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