problem with extra entries in a matrix!

Question

Ano 2017-5-22

0
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编辑： Stephen23 2017-5-22

Hello, I would like to fill a matrix but I have a problem in filling it, because I get some extra entries even though I have initialized my matrix to the required size. Please find the problematic loop bellow, and hope you can help, thank you.

 year = 1;
i = 0;
Nbrtot = 6;
MyResults  = zeros(Nbrtot, 1);
for l = 1:year
    for nbrrepetiton = 0:l
        for NoYes = [0 1]
            for semester = [1 2]
                i = i + 1;
                MyResults(i)  = i;
            end
        end
    end
end

Note: using this code My matrix MyResults has 2 extra entries.

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KSSV 2017-5-22

How you are sure that Nbrtot = 6 ?

Ano 2017-5-22

what do you mean ?? for me Nbrtot is the total number of element that should be in the whole summation it is fixed but I have divided my problem into those loops in order to simplify it . any suggestions how to make the entries exactly as specified ?

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Answer 1

Stephen23 2017-5-22

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https://ww2.mathworks.cn/matlabcentral/answers/341323-problem-with-extra-entries-in-a-matrix#answer_267916

编辑：Stephen23 2017-5-22

在 MATLAB Online 中打开

for l = 1:year          % one iteration
for nbrrepetiton = 0:l  % two iterations
for NoYes = [0 1]       % two iterations
for semester = [1 2]    % two iterations

Each nested loop multiplies the total iterations by its own number of iterations, so we get:

1x2x2x2 = 8

So we find that MATLAB is doing exactly what you told it to do: eight iterations in total. There is no reason to expect six iterations here.