[Rcpp-devel] armadillo mailing list?

Romain Francois romain at r-enthusiasts.com
Thu Jul 29 13:23:51 CEST 2010


Le 29/07/10 09:30, baptiste auguie a écrit :
> Dear all,
>
> I'm porting some R code to C++ using the armadillo framework (I'm
> using operations on complex matrices, etc.). The final goal is of
> course to wrap the code using RcppArmadillo. Currently, I'm still
> struggling with my little C++ knowledge. Does anyone know of an
> Armadillo mailing list where I could ask C++ questions?

 From armadillo's faq http://arma.sourceforge.net/faq.html
you can find a link to a forum:
http://sourceforge.net/apps/phpbb/arma/

> Just in case, I'll ask here too. I have a small 3x3 matrix that I
> generate in a nested for loop, and I want to insert this matrix as a
> block inside a larger matrix. In R language, I'd want to use a
> construct like,
>
> A[ seq(ii, ii+2), seq(jj, jj+2)]<- matrix(rnorm(9), 3, 3)
>
> I tried the following as a test,
>
> mat A = "0 0 0; 0 0 0; 0 0 0;";
> A.submat(1,1,1,1) = 1;
>
> but it seems that .submat is only to view elements, not assign them
> (the `[<-` method in R). Any tip?
>
> Sincerely,
>
> baptiste

That is the kind of thing we should add in Rcpp sugar at some point, but 
currently I don't know how to.

Romain

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Romain Francois
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