How to specify the number of odd and even numbers from a random generator in R?
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Clash Royale CLAN TAG#URR8PPPHow to specify the number of odd and even numbers from a random generator in R?
I need to generate a random selection of 9 whole numbers from 1 to 40 with the following condition: the output must contain 5 even numbers and 4 odd numbers.
random
even
odd
I have the following code to generate 9 random numbers:
x1<- sample(1:40, 9, replace=F)
> x1
[1] 2 36 6 10 39 17 14 11 25
I now need to add the odd and even numbers condition in the equation. How can I do this?
2 Answers
2
Assuming the order of the numbers does not matter, you could try
c(sample(seq(2,40,by=2), 5, replace=F), sample(seq(1,39,by=2), 4, replace=F))
where seq(2,40,by=2) generates the even numbers, and seq(1,39,by=2) generates the odd numbers. If the order does matter (i.e. it should also be random), you can wrap the outer c with sample:
seq(2,40,by=2)
seq(1,39,by=2)
c
sample
sample(c(sample(seq(2,40,by=2), 5, replace=F),sample(seq(1,39,by=2), 4, replace=F)))
Hope this helps!
When running the codes where order matters, I get the following error message: Error in sample.int(length(x), size, replace, prob) : cannot take a sample larger than the population when 'replace = FALSE'
– user3115933
4 mins ago
@user3115933 oops, my bad! Fixed it ;) I replaced
c instead of wrapping it.– Florian
3 mins ago
c
You could try this:
sample(c(2*sample(0:19, 4, replace=FALSE) + 1, 2*sample(1:20, 5, replace=FALSE)))
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@G5W That's a good idea, I did not think of that. Added that to the solution.
– Florian
8 mins ago