Thanks, I was forgetting the recycling rule.
L. 2008/3/9, Gabor Grothendieck <[EMAIL PROTECTED]>: > Use TRUE. > > > On Sun, Mar 9, 2008 at 5:05 AM, Laurent Gautier <[EMAIL PROTECTED]> wrote: > > Dear list, > > > > I am having a question regarding the extract function "[". > > > > The man page says that one usage with k-dimensional arrays is to > > specify k indices to "[", with an empty index indicating that all > > entries in that dimension are selected. > > > > The question is the following: is there an R object qualifying as an > > "empty index" ? I understand that the lazy evaluation of parameters > > allows one to > > have genuinely missing parameters, but I would like to have an object > > instead. I understand that one can always have an if/else workaround, > > but I thought should ask, just in case. > > > > I tried with NULL but with little success, as it appears to give the > > same results > > as an empty vector. > > > m = matrix(1, 2, 2) > > > m[1, NULL] > > numeric(0) > > > m[1, integer(0)] > > numeric(0) > > > > Since I was at it, I noted that the result obtained with "numeric(0)" > > definitely makes sense but could as well be seen as challenging the > > concept of an empty index presented in the man page (One could somehow > > expect the presence of an object meaning "everything" rather than > > "missingness" meaning it). > > > > > > Thanks, > > > > > > Laurent > > > > > ______________________________________________ > > R-devel@r-project.org mailing list > > https://stat.ethz.ch/mailman/listinfo/r-devel > > > -- -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iEYEARECAAYFAkYgwJ4ACgkQB/w/MLoyRDeQlgCeMp8v69/Wy24Q4IaBVhoG1M5R 2h4AoIOTvKbrFpTklRDjV7u8tEOeSQqt =JPph -----END PGP SIGNATURE----- ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
