Le 14/06/2017 à 15:21, Douglas Bates a écrit :
On Wed, Jun 14, 2017 at 3:59 AM Serguei Sokol <[email protected]
<mailto:[email protected]>> wrote:
Le 13/06/2017 à 18:24, Douglas Bates a écrit :
> On Tue, Jun 13, 2017 at 10:56 AM Binxiang Ni <[email protected]
<mailto:[email protected]> <mailto:[email protected]
<mailto:[email protected]>>> 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).
That is the format of the dgTMatrix class from the Matrix package for R but not, as far as I can tell, in Armadillo. A brief glance at the Armadillo
documentation indicates that sparse matrices are always in the compressed sparse column (CSC) format.
Indeed, but nothing prevents Binxiang to develop a wrap() that will convert
armadillo format to one or many of R formats, right?
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