[R] Funny result from rep(...) procedure
Erik Iverson
eriki at ccbr.umn.edu
Thu Feb 18 19:13:05 CET 2010
Cannot reproduce, what is branches? If you can narrow it down to a
"commented, minimal, self-contained, reproducible" example, you're far
more likely to get help from the list.
dkStevens wrote:
> I'm observing odd behavior of the rep(...) procedure when using variables as
> parameters in a loop. Here's a simple loop on a vector 'branches' that is
> c(5,6,5,5,5). The statement in question is
> print(c(ni,rep(i,times=ni)))
>
> that works properly first time through the loop but the second time, when
> branches[2] = 6, only prints 5 values of i.
>
> Any ideas, anyone?
>
> iInd = 1
> for(i in 1:length(branches)) {
> print((1:branches[i])+iInd-1) # iInd is a position shift of the index
> ni = branches[i]
> print(i)
> print(ni)
> print(c(ni,rep(i,times=ni)))
> # ... some interesting other stuff for my project that gets wrecked because
> of this issue
> iInd = iInd + branches[i]
> }
>
> # first pass through loop
> [1] 1 2 3 4 5 # branches[1] + iInd - 1 content
> [1] 1 # i value to repeat 5 times
> [1] 5 # ni = 5 on 1st pass
> [1] 5 1 1 1 1 1 # five values - 1 1 1 1 1 - OK
>
> # second pass through loop
> [1] 6 7 8 9 10 11 # branches[2] + iInd - 1 content
> [1] 2 # i value to repeat 6 times
> [1] 6 # ni = 6 on 2nd pass
> [1] 6 2 2 2 2 2 # 6 'twos' but only shows 5 'twos'
> print(c(ni,rep(i,times=ni))) - why not 6?
>
>
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