[Rcpp-devel] [RcppArmadillo] Result of Rcpp Wrap() for Sparse Matrix

[Serguei Sokol]

Le 13/06/2017 à 18:24, Douglas Bates a écrit :
> On Tue, Jun 13, 2017 at 10:56 AM Binxiang Ni <binxiangni at gmail.com <mailto:binxiangni at gmail.com>> wrote:
> 
>     Hi,
> 
>     I am working on fixing sparse matrix conversion for RcppArmadillo. Now a problem comes up to me: what kind of sparse matrix is expected to pass from
>     Armadillo to R? That is, what should the result of wrap() be? dgCMatrix(if logical, lgCMatrix or ngCMatrix)  or their original type?
> 
> 
> What do you mean by "their original type"?
> 
> It seems that the correspondence is
> Armadillo           Matrix package
> sp_mat       <=> dgCMatrix
> sp_cx_mat <=> zgCMatrix
> sp_imat      <=> igCMatrix
I would also consider the format used in a package slam.
It simply stores the indexes and non-zero values in a triplet (i,j,v).

Serguei.