El sáb., 4 ago. 2018 a las 15:32, Rui Barradas (<ruipbarra...@sapo.pt>) escribió: > > Hello, > > Maybe I am not understanding how negative indexing works but > > 1) This is right. > > (1:10)[-1] > #[1] 2 3 4 5 6 7 8 9 10 > > 2) Are these right? They are at least surprising to me. > > (1:10)[-0] > #integer(0) > > (1:10)[-seq_len(0)] > #integer(0) > > > It was the last example that made me ask, seq_len(0) whould avoid an > if/else or something similar.
I think it's ok, because there is no negative zero integer, so -0 is 0. 1.0/-0L # Inf 1.0/-0.0 # - Inf And the same can be said for integer(0), which is the result of seq_len(0): there is no negative empty integer. Iñaki > > > Thanks in advance, > > Rui Barradas > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
