Hi, all.
I'm curious about the following behavior in list subsetting:
> t1 <- as.list(1:10)
> t2 <- 1:10
> t2 == 5
[1] FALSE FALSE FALSE FALSE TRUE FALSE FALSE FALSE FALSE FALSE
> t1[t2==5]
[[1]]
[1] 5
> t1[[t2==5]]
Error: attempting to select more than one element> t1[[which(t2==5)]]
[1] 5
I don't understand why the second-to-last command gives an error, rather
than the same result as the third-to-last command. After all, only one
element of the indexing vector is TRUE, so as far as I can tell I'm really
only trying to select one element.
The final command does what I want (as does t1[t2==5][[1]]), so this isn't
an urgent question, but I've looked through the documentation and can't
figure out why t1[[t2==5]] doesn't work.
Thanks for any help.
Matt Wiener
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