On 27 April 2022 at 20:58, Roberto Spadim wrote: | Hello folks, | I'm converting some R functions to RCpp at | https://github.com/OVVO-Financial/NNS/ | | My problem is with a R "cast" function | | https://github.com/OVVO-Financial/NNS/blob/d3f37c6f217a41ce15b31f7a840b6b1ad63e5f36/R/Partial_Moments.R#L20 | | basically this line: | | --- | LPM <- function(degree, target, variable){ | if(any(class(variable)%in%c("tbl","data.table"))) variable <- | as.vector(unlist(variable)) | ... | } | --- | | My Rcpp version don't accept data.table type, it return an error of | type not allow: | | Error in LPM(2, 0, tail(appended_returns, 1)) : | Not compatible with requested type: [type=list; target=double]. | | Is there some way to accept a "anytype" at Rcpp, and convert it to | numericvector when need?
In a way. We have a more-or-less FAQ about how to accomodate 'different run-time types' (think: int vector vs double vector) at compile time. The easiest is to use a SEXP which *is* already your "anytype" as it (most literally) covers "any" type in R. See for example https://gallery.rcpp.org/articles/rcpp-wrap-and-recurse/ which shows the basic pattern of switching on TYPEOF(). Otherwise, a tip: decompose compound expressions if(any(class(variable)%in%c("tbl","data.table"))) variable <- as.vector(unlist(variable)) into more basic assignments (on the C++ side). We are getting some wonderful help from the compiler but the template meta-programming driving this is finicky. Do NOT assume you can stack expressions as you might in R. No shame in doing multiple basic expressions -- the compiler (once it knows what to do) may well optimise temporaries away. Dirk | My Rcpp version is: | | https://github.com/OVVO-Financial/NNS/blob/NNS-Beta-Version/src/partial_moments_rcpp.cpp#L68 | | and fucntion signature is: | NumericVector LPM_CPv(const double degree, const NumericVector target, | const NumericVector variable) { | | i think i should use SEXP as "anytype" and at function body check if I | should "cast" to NumericVector | _______________________________________________ | 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 -- dirk.eddelbuettel.com | @eddelbuettel | e...@debian.org _______________________________________________ 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
