(This article was first published on 0xCAFEBABE, and kindly contributed to R-bloggers)
How to set the default seed for the RNG behind the runif()
, sample()
and other command? Well, there are several ways doing that (like setting .Random.seed
directly), but as the documentation states, set.seed()
is the recommended way to specify seeds.
> ?set.seed
> set.seed(0)
> runif(1,0,1)
[1] 0.8966972
> set.seed(0)
> runif(1,0,1)
[1] 0.8966972
> set.seed(0)
> sample(1:10, 10)
[1] 9 3 10 5 6 2 4 8 7 1
> sample(1:10, 10)
[1] 1 2 9 5 3 4 8 6 7 10
> set.seed(0)
> sample(1:10, 10)
[1] 9 3 10 5 6 2 4 8 7 1
> sample(1:10, 10)
[1] 1 2 9 5 3 4 8 6 7 10
BTW runif()
stands for random uniform, not a “run if…” branching expression. Tricky naming conventions 😉
Further reading
- David Smith’s blog post at Revolution Analytics
> ?set.seed
> ?runif
> ?sample
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