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