On 2010-08-23, at 6:15 AM, Barry Rowlingson wrote: > On Sun, Aug 22, 2010 at 4:33 PM, ivo welch <ivo.we...@gmail.com> wrote: >> I have found that my students often make the mistake of >> mixing up comparisons and assignments with negative numbers: >> >> if (x<-3) do_something; > > If you tell your students not to use '<-' for assignment, then they > can't make this mistake, because = for assignment has additional > restrictions on it:
The students are trying to *compare* to a negative number, and trip on R's parsing of "<-". They could use '=' for assignment all they want (which I thought is being discouraged as a code style these days, BTW), and they'll still run into this problem. Davor ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
