On Jul 29, 2010, at 1:23 PM, Romain Francois wrote: > 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/
I don't know how I'd missed it, thanks! It turns out that my example would work, one only needs to make sure that the replacement has the correct type (matrix) and dimensions: this works mat A = "0 0 0; 0 0 0; 0 0 0;"; A.submat(1,1,1,1) = ones(1); Thanks, baptiste > >> 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 > > -- > Romain Francois > Professional R Enthusiast > +33(0) 6 28 91 30 30 > http://romainfrancois.blog.free.fr > |- http://bit.ly/aryfrk : useR! 2010 > |- http://bit.ly/bc8jNi : Rcpp 0.8.4 > `- http://bit.ly/dz0RlX : bibtex 0.2-1 > _______________________________________________ Rcpp-devel mailing list [email protected] https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
