How do i select random indicies from an array?
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I have an array of 10 by 6. is there a way I can randomly select rows from this particular array and everything within it.
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Image Analyst
2015년 3월 5일
Let's say you have a 10-by-6 matrix m, and you want to select 7 rows at random and make sure there are no repeats. Do this:
m = randi(9, 10,6)
randomRows = randperm(size(m, 1), 7)
randomRows is the array of row numbers , not the actual 6 element rows themselves.
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Joseph Cheng
2015년 3월 5일
편집: Joseph Cheng
2015년 3월 5일
yes, you can perform something like this. Lets say your 10 by 6 array is called A;
then to get the random row(s) you can do
A(randi(10,N,1),:)
where 10 is the number or rows in A (or you can do size(A,1) if you do not want to hard code 10), N is the number of random rows you want to select and the : selects all columns.
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Image Analyst
2015년 3월 5일
Just a watchout: With randi(), it's really random meaning that there is a possibility that the same row might be "chosen" twice or more. If you don't want that (you want, say, 5 rows and all rows to be unique), then use randperm() instead.
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