[Rcpp-devel] A question in slides from Rcpp workshop

[Zhongyi Yuan]

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 <bates at stat.wisc.edu> wrote:

> On Fri, Aug 5, 2011 at 5:27 AM, Zhongyi Yuan <yuanzygoso at gmail.com> 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
> > Rcpp-devel at lists.r-forge.r-project.org
> > https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
> >
> >
>
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