Hi Douglas, Thank you for the reply. That clarifies quite a bit. But still, it does not explain the different behavior of those examples, does it? One moment ago, I was thinking that the L suffix might have made it constant and hence can't be modified. Looks like I am wrong. (And fun(1:3) gives the same result too.)
Zhongyi On Fri, Aug 5, 2011 at 3:49 AM, Douglas Bates <[email protected]> wrote: > On Fri, Aug 5, 2011 at 5:27 AM, Zhongyi Yuan <[email protected]> wrote: > > Dear useR's, > > > > After I found Rcpp a few days ago, I've been very excited collecting > > documents for learning. But still I find myself understand little. > > Here's a question I want you to help me with. > > > > In page 17 of Dirk and Romain's slides from part2 of the Apr 28 Rcpp > > workshop (here's a link: > > http://dirk.eddelbuettel.com/papers/rcpp_workshop_part_2_details.pdf), I > > can't figure out why the two examples behave differently. > > And also, why are people using 1L:3L? What not just 1:3? > > It happens that they are the same but only because 1:3 generates an > integer sequence by default. Most of the time 1 gives a double > precision floating point number whereas 1L is an integer. Those with > long-time experience in writing R code tend to use the L when they > know that an integer is wanted, just to bypass the conversion step. > > > Maybe I am asking silly question? But please do help me. I couldn't find > an > > answer on google. > > Thank you. > > > > Best, > > Zhongyi > > > > > > _______________________________________________ > > Rcpp-devel mailing list > > [email protected] > > https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel > > > > >
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