Are there any functions to randomly pick the minimum element from a vector if the vector has multiple minimum elements?

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Ryan 2020-7-15

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评论： Walter Roberson 2020-7-15

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Function min() picks the first minimum element from a vector if the vector has multiple minimum elements.

I want to randomly pick the minimum element from all the minimum elements and get its value and index.

Could you tell me if there is a function to do that?

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Walter Roberson 2020-7-15

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No, there is no function provided for that. You can write such a function, though. The difficulty of doing it will depend upon whether you are working with a vector or something that is at least 2D (in which case it has to process per row or per column)

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Ryan 2020-7-15

Thanks a lot!

Actually, I though of setting the value as Inf. But I am afraid the program will have bugs during the later programming. Seriously...

It is not homework. Seriously...

Anyway, thanks a lot!

Walter Roberson 2020-7-15

在 MATLAB Online 中打开

NR = 3;
[sortedvals, sortidx] = sort(YourVector);
LastSameIdx = 1;
MinVals = zeros(1,NR);
RandomIdx = zeros(1,NR);
for K = 1 : NR
    LastSameIdx = 1;
    while LastSameIdx < length(YourVector) && sortedvals(1) == sortedvals(LastSameIdx+1)
      LastSameIdx = LastSameIdx + 1;
    end
    thisidx = randi(LastSameIdx);
    MinVals(K) = sortedvals(thisidx);
    RandomIdx(K) = sortidx(thisidx);
   sortedvals(thisidx) = [];
   sortidx(thisidx) = [];
end