On 3 February 2014 at 12:59, Douglas Bates wrote: | On Mon, Feb 3, 2014 at 11:48 AM, Dirk Eddelbuettel <[email protected]> wrote: | | | On 3 February 2014 at 10:23, French, Joshua wrote: | | Soren and Doug, | | | | Thanks for the info about the sparse matrices. I'll give it a go and | seen what | | happens. If it works out, then perhaps I'll be able to provide a nice | | RcppGallery example. | | Yes -- there isn't much yet in RcppArmadillo but this is expected to | grow. And CRAN now has rARPACK so we get cheaply to the object code too. | | One last comment I should have made earlier: "dense" data from R comes over | cheaply as a SEXP; "sparse" will always require a copy. Keep that in | mind, | and on the margin don't believe anything any of us say but keep profiling | and | measuring :) | | | Not really. RcppEigen offers conversion of SEXPs to Eigen::SparseMatrix and | Eigen::MappedSparseMatrix types. The second uses the storage from R without | copying and hence should generally be declared with the const modifier.
Oooops. My bad. I guess I generalized from my less performing converters contributed to RcppArmadillo. Time permitting, maybe I should have another look at RcppEigen and see if I can do better for RcppArmadillo. | I think that wonderful vignetter by Bates and Eddelbuettel describes this :-) :-) Dirk -- Dirk Eddelbuettel | [email protected] | http://dirk.eddelbuettel.com _______________________________________________ Rcpp-devel mailing list [email protected] https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
