Hi all... My students were conflating grepping for a value in a vector to get the index, and then removing it with [-index], for instance like this:
set.seed(17) v <- rnorm(20) s <- v[-1.18] They were trying to remove the 12th value in v, which is -1.18 or so. But the result is, as documented in ?Extract, to coerce 1.18 to the next lowest integer, and remove the 1st value of v, not the 12th value. This strikes me as something that ought to give an error or warning, or at least be in the R Inferno, but I couldn't find it there. Under what circumstances would the documented behavior be valuable? I can see that it avoids doing floor or as.integer in computations where an index is needed but real numbers are generated for whatever reason, but is that common? Thanks for any insight. Bryan ************* Bryan Hanson Acting Chair Professor of Chemistry & Biochemistry DePauw University, Greencastle IN USA ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
