FYI to anyone who stumbles across this page...MathWorks staff saw this question and generated an enhancement request for the MinMax block on 2 OCT 2017. Even if that eventually gets added to base Simulink, it doesn't help me in the near term at all.
Index for array max (or min) in Simulink without variable-size signal or MATLAB Function block
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In Simulink I have a signal that is a 1-D array. I need to get the index associated with the first maximum (or minimum) value in the array. In MATLAB, that's simply this:
>> [val,idx] = max([2 3 6 8 4 7 8 4 5 6])
val =
8
idx =
4
where idx is the item I'm looking for.
Trying to do that in Simulink seems to be much less straightforward. The MinMax block does not offer an option to output the index of the first maximum value.
Coupling a MinMax with a Find Nonzero Elements blocks as in the suggestion on this page does do the trick, but it comes with the problem that the output of the find block is a variable-sized signal. I don't want it to be a variable sized signal; I just want the first index.
One could also use a MATLAB Function block and use the MATLAB min or max function as above, but MATLAB Function blocks take obnoxiously long to compile and often generate code with a lot of gunky overhead.
Is there not a simple, clean, cheap way to get the first max index?
採用された回答
Peter Anderson
2018 年 4 月 26 日
I was looking at this sort of problem (for me it was find the first non-zero element) and came up with a solution that doesn't involve toolboxes, MATLAB function blocks or variable size signals. You can solve it with a for-iterator subsystem.
Your min/max case will be slightly different but will have very similar structure.
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/187886/image.png)
3 件のコメント
Juan Ocampo
2018 年 12 月 4 日
Congratulations great solution, thank you very muck for shearing it, i was thinking for a solution to this problem for a while and your solution is perfect.
その他の回答 (4 件)
sl
2019 年 2 月 13 日
Hi Michael,
The logic below will fulfill your need.
![Capture.PNG](https://www.mathworks.com/matlabcentral/answers/uploaded_files/203929/Capture.png)
2 件のコメント
Dick Benson
2020 年 8 月 5 日
Good solution.
The Index Out really needs to be part of the min/max blocks.
One could use the sort block, but what a waste of CPU cycles.
Kirankumar Bacchewar
2021 年 10 月 15 日
編集済み: Kirankumar Bacchewar
2021 年 10 月 15 日
This model can be used to find min,max and its Index. Just modify the size of the input array in selector blocks. Hope its helpful.
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/768131/image.png)
0 件のコメント
Mohammad Ali Sadeghian
2023 年 4 月 27 日
Hello,
you can use 2-D Maximum block with value and index.
ALI
0 件のコメント
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