Choose pairs of integers without repeating this selection in a loop
조회 수: 4 (최근 30일)
이전 댓글 표시
Hi. I want select randomly two number by 'randsample' or 'randperm' function in a loop (for intermediate recombination in evolutionary strategy matlab code). But I want any pair of numbers can be selected only once. For example if selected [1 2], in next time [1 2] or [2 1] are not selected. please help me. Thanks
댓글 수: 0
채택된 답변
Image Analyst
2014년 4월 28일
Seems really, really easy. Did you try it? This is what I got:
theNumbers = randperm(50) % Whatever number you want.
for k = 1 : 2 : length(theNumbers)/2
selection = theNumbers(k:k+1) % Report this selection to command window.
end
댓글 수: 3
Image Analyst
2014년 4월 28일
I have no idea what that means. First of all, I have selection, not selected. Secondly it's a numerical array, not a cell array. And third, you said "any pair of numbers can be selected only once " which seems to be a direct contradiction of saying it still "has a chance of being selected."
추가 답변 (1개)
Geoff Hayes
2014년 4월 28일
Hi Ehsan,
One option is to keep track of a list of all the possible choices for your recombination, randomly select a pair of indices into that list, remove those two from your list of choices and then repeat for the next random selection (the two that you removed previously will no longer be in the list to choose from):
N = 26; % the max number of choices
recomChoices = 1:N; % the vector of choices
rndPairIndcs = randperm(length(recomChoices),2); % the randomly chosen indices for recombination
rndPair = recomChoices(rndPairIndcs); % the numbers/ids for recombination (i.e. 1,2)
recomChoices(rndPairIndcs) = []; % remove that pair from the list
Hope that this helps!
Geoff
댓글 수: 0
참고 항목
카테고리
Help Center 및 File Exchange에서 Loops and Conditional Statements에 대해 자세히 알아보기
제품
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!