Find at least 5 consecutive values above a certain threshold in a vector?
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I have a vector
M = [3,3,5,7,8,8,9,7,4,3,2,1,7,6,5,2,2,2];
I want to find at least 5 consecutive values which are above the threshold, which is 4. So the vector will be
N = [5,7,8,8,9,7]
Could anyone help me with this? Thanks.
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Accepted Answer
Walter Roberson
on 17 Apr 2019
mask = M > 4;
starts = strfind([0 mask], [0 1 1 1 1 1]);
stops = strfind([mask 0], [1 1 1 1 1 0]);
N = M(starts(1) : stops(1))
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More Answers (2)
Akira Agata
on 17 Apr 2019
If there are 2 or more consective values above the threshold, the following is one possible solution.
(* The following needs Image Processing Toolbox)
M = [3,3,5,7,8,8,9,7,4,3,6,5,8,5,8,2,1,7,6,2,6,2];
idx = M > 4;
idx = bwareafilt(idx,[5,Inf]);
label = bwlabel(idx);
N = cell(max(label),1);
for kk = 1:max(label)
N{kk} = M(label == kk);
end
Result:
>> N
N =
2×1 cell array
{1×6 double}
{1×5 double}
>> N{1}
ans =
5 7 8 8 9 7
>> N{2}
ans =
6 5 8 5 8
>>
9 Comments
Akira Agata
on 9 Apr 2021
OK. I believe the error was due to the difference between the 3D matrix in my sample code and the real data.
Is it possible to upload part of your real data and the modified code which generates the error?
Ahmad Bayhaqi
on 1 May 2021
Hi @Akira Agata
Thank you for your code. It works for me.
However, since my temperature data contains date. How the result of looping includes the datetime to define when the temperature is higher than threshold?
Thank you very much
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