cut of zeros from a matrix based on the longest non-zero row

A=[ 1 2 0 0 0 0;3 4 5 0 0 0;5 6 0 0 0 0];
lastnonzero=find(any(A~=0,1),1,'last') % the last column with a non-zero row
lastnonzero = 3
A(:,lastnonzero+1:end)=[]
A = 3×3
     1     2     0
     3     4     5
     5     6     0

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Net Fre 2021-11-22

OK, much better than mine :)

Didn't know about any. Notice that your code will ingore non-zero negatives.

Dave B 2021-11-22

oops, I updated to be ~=0, thanks for catching that! (technically it can just be any(A), but I find that specifying the condition explicitly is more readable)

any and all are very useful! they also take a dimension arg, or the keyword 'all' which I use often.

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Answer 2

Net Fre 2021-11-22

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https://ww2.mathworks.cn/matlabcentral/answers/1592769-cut-of-zeros-from-a-matrix-based-on-the-longest-non-zero-row#answer_837454

编辑：Net Fre 2021-11-22

在 MATLAB Online 中打开

Hi

You can use the cumprod function.

your code line can look like this:

% a = some matrix
idx = max(sum(cumprod(a~=0,2)),2)
output = a(:,1:idx)

I suggest you break the one line into several ones just to see what each function does.

hope this helps.

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