On 13 January 2013 at 08:13, Jeff Ryan wrote: | Nice work. I'll be frank, I am not overly interested in this from a practical | standpoint myself, since it doesn't solve a near term problem for me - not | being a C++ guy and all and being perfectly at home in the R API.
That's ok. All an external package needs from you are stable interfaces (a given) that are also declared in init.c and can hence be accessed from other R package using the function pointer dereferencing you yourself use from zoo. I think you and can hash out the issues I already signaled in off-line mail and then maybe see if there are a handful of additional useful functions. Ultimately, I think xts draws much of its (awesome) power from how you mix R and C, and we won't be able to fully replicate that coming from the C API side only. Yet that being said, there may be good usecase for basic subsetting, merging, expanding,... from the C API side. | But, I will certainly add the needed init.c stuff and help facilitate where I | can. Sounds good. Dirk | Cool stuff. | Jeff | | | On Sat, Jan 12, 2013 at 11:10 PM, Dirk Eddelbuettel <e...@debian.org> wrote: | | | On 12 January 2013 at 02:23, Wu Wush wrote: | | In my experience, we could write some functions based on exposed API: | | - Query a subset of xts object based on row | | subset(`Rcpp::DatetimeVector` or integer vector) and column | | subset(string vector or integer vector) | | That does not necessarily need the xts API. As the data of an xts is just | a | numerical matrix we can access the matrix directly -- and the index is a | vector of datetimes. I sketched something in a post on the Rcpp Gallery: | | http://gallery.rcpp.org/articles/getting-attributes-for-xts-example/ | | | - Convert `Rcpp::Matrix<RTYPE>` instance to xts object with given | | index(`DatetimeVector`) | | I think for that one most often calls back to R to invoke 'as.xts()'. | Eg that is what Rcpp itself does to create a dataframe. | | | I have implemented these features, so I only need a skeleton of | | Rcpp-like package. Could you give me some suggestion about this? | | You can just use any odd package generator -- eg Rcpp.package.skeleton() -- | or copy and alter an existing package. | | But out of curioisty, I went the other way to day today and played a little | with | a basic RcppXts package to see if we could get to the exported functions of | the xts API. There are fewer than the help(xtsAPI) shows -- what really | counts is its src/init.c. If commmitted this to R-Forge as RcppXts_0.0.1 | and | the basic work for me on Ubuntu. But between 32 and 64 bit Windows devel | and | release, one fails cosistently (64 bit r-release). | | Dirk | | -- | Dirk Eddelbuettel | e...@debian.org | http://dirk.eddelbuettel.com | | | | | -- | Jeffrey Ryan | jeffrey.r...@lemnica.com | | www.lemnica.com -- Dirk Eddelbuettel | e...@debian.org | http://dirk.eddelbuettel.com _______________________________________________ Rcpp-devel mailing list Rcpp-devel@lists.r-forge.r-project.org https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
