[Rcpp-devel] Rcpp-quickref patch - Inline, Random

[Romain Francois]

Le 07/12/10 11:15, Christian Gunning a écrit :
> Attached is a patch relative to pkg/Rcpp/inst/doc/Rcpp-quickref.

Thanks. I will have a look tonight if nobody else does it before me 
(please do).

> I added Douglas' suggestion to the Matrix section.  In addition are
> reference examples for inline and the random functions.
>
> There was a recent list question about dnorm, and I ran across similar
> confusion.  Is the default argument cascade the same for all of the d*
> family?  For dnorm, assuming numvec contains {-1, 0, 1}, we have:
>
> //Working:
> NumericVector works1, works2;
>   works1 = dnorm(numvec, 0, 1, false);
>   works2 = dnorm(numvec, 0, false);
>
> As far as I could tell, all other combinations of missing arguments
> fails at compile time.

It is useful if you actually send us what you  tried to compile, hoiw it 
failed, why you though it would work, etc ...

> Since e.g. rnorm(10) works, this seems a bit
> counter-intuitive.  Personally, this isn't a priority for me - just
> trying to figure out the system.
>
> best,
> xian

Consider this:

require( inline )
require( Rcpp )

fx <- cxxfunction( , '
     RNGScope scope ;

     return List::create(
         rnorm(10),
         rnorm(10, 10.0),
         rnorm(10, 10.0, 100.0)
         ) ;

', plugin = "Rcpp" )
fx()

You cannot have missing arguments "in the middle" in C++.


-- 
Romain Francois
Professional R Enthusiast
+33(0) 6 28 91 30 30
http://romainfrancois.blog.free.fr
|- http://bit.ly/gpCSpH : Evolution of Rcpp code size
|- http://bit.ly/hovakS : RcppGSL initial release
`- http://bit.ly/iaxTdO : parser 0.0-12