Rcpp: An R / C++ interface


	Dirk Eddelbuettel				Rcpp: An R / C++ interface

	Bio Code rcpp rpostgresql rdieharder littler random digest rquantlib beancounter smtm yahooquote octave-mt octave-pg Linux Quantian About Blog				Overview The Rcpp package provides C++ classes that greatly facilitate interfacing C or C++ code in R packages using the `.Call()` interface provided by R. Rcpp provides matching C++ classes for a large number of basic R data types. Hence, a package author can keep his data in normal R data structure without having to worry about translation or transfer to C++. At the same time, the data structures can be accessed as easily at the C++ level, and used in the normal manner. The mapping of data types works in both directions. It is as straightforward to pass data from R to C++, as it is it return data from C++ to R. The following two sections list supported data types. Transfer from R to C++ Standard R datatypes that are understood in C++ are named lists containing numeric (i.e. floating point), integer, character, logical (i.e. boolean) or Date and Datetime (i.e. POSIXct) arguments; data frames containing numeric, integer, logical, character, Date, Datetime or Factor columns; named vectors containing numeric or integer values, vectors and matrices of different values character strings Transfer from C++ to R Standard C++ datatypes can be returned to R in a named list, the most general data type in R. Permissible components of the returns list are the following C++ types: double (scalar as well as vectors and vectors of vectors), int (scalar as well as vectors and vectors of vectors), string, STL vector types and vector types of int and double STL vector of strings internal Rcpp types RcppDate, RcppDateVector, RcppDatetime, RcppDatetimeVector, RcppStringVector, RcppVector of int or double, RcppMatrix of int or double, RcppFrame Usage for package building Rcpp provides a header file and a library inside the installed package in the directory `lib`. From within R, you can compute the directory location via `system.file("lib", "Rcpp.h", package="Rcpp")`--but both are provided for your via the functions `Rcpp::RcppCxxFlags()` and `Rcpp::RcppLdFlags()`. So we can just use the following as a file `src/Makevars` (or `src/Makevars.win` on Windows) PKG_CXXFLAGS=`Rscript -e 'cat(Rcpp:::RcppCxxFlags())'` PKG_LIBS=`Rscript -e 'cat(Rcpp:::RcppLdFlags())'` See the help page for `Rcpp-package` for details. History Rcpp was initially written by Dominick Samperi to ease contributions to the RQuantLib project, and then released as a project in its own right. During 2006, Dominick made several releases under the RCpp name (versions 1.0 to 1.4) before he changed the name to RCppTemplate and made more releases (1.5 to 5.2). The project saw no public releases during 2007 and then first ten months of 2008. I have now adopted Rcpp and started to make new releases, starting with 0.6.0 which arrived on CRAN in early November 2008. InFrequently Asked Questions What about using `LinkingTo` in the DESCRIPTION file? Great question, but nobody has explained yet how to do that for C++. For C, we do what lme4 and matrix do. But for C++? Let us know if you know how to do this. ChangeLog 2008-12-02 Dirk Eddelbuettel * Release 0.6.2 * R/RcppLdPath.R: Correct output for the default Linux case 2008-11-30 Dirk Eddelbuettel * Release 0.6.1 * src/Makevars: Added, replacing src/Makefile: thanks to Simon for a rewrite that provides OS X support * src/Makefile: Retired * src/Makefile.win: Now build libRcpp.a instead of Rcpp.a * src/Rcpp.{cpp,h}: Removed #ifdef statements related to QuantLib and Date ops as we no longer need to split this off -- one build for all uses; also added another date offset for the difference between the Unix epoch of Jan 1, 1970 and what certain spreadsheets use (which is what QuantLib) follows. With this change, Rcpp is completely decoupled from QuantLib headers, yet can be used from QuantLib 0.2.10 or later. However, this also removes data conversion from R/Rcpp to QL as Rcpp no longer 'knows' QL. * R/RcppLdPath.R: Adds new functions RcppLdPath() to return lib/ directory path, and RcppLdFlags() to return arguments, including the optional rpath settings on Linux * R/RcppExample.R: Added new example 'RcppVectorExample()', extended default print method for examples * man/Rcpp-package.Rd: Expanded / updated documentation of package use when building other packages * cleanup: Removing static libraries too but do not remove src/Makevars 2008-11-05 Dirk Eddelbuettel * Release 0.6.0 * New maintainer * src/Makefile{,.win}: New files, including functionality from both configure and RcppSrc/Makefile; we now build two libraries, one for use by the package which also runs the example, and one for users to link against * src/Makevars.in: Removed * src/Rcpp.{cpp,h}: moved in from ../RcppSrc * src/Rcpp.{cpp,h}: Add new type RcppDatetime corresponding to POSIXct in with full support for microsecond time resolution between R and C++ * man/: Several new manual pages added configure{,.in,.win}: Removed as src/Makefile* can handle this more easily * DESCRIPTION: Minor cleanup and reformatting, Date: now uses svn:keyword Date property * NAMESPACE: Renamed RcppTemplateVersion to RcppVersion, deleted RcppDemo * demo/ directory removed as vignette("RcppAPI") is easier and more reliable to show vignette documentation * R/zzz.R: RcppTemplateDemo() removed, vignette("RcppAPI") is easier * man/RcppTemplateDemo.Rd removed as well * R/RcppExample.R: reindented, rewritten to set default arguments * R/RcppTemplateVersion.R: renamed to RcppVersion.R * man/RcppTemplateVersion.Rd: renamed to RcppVersion.Rd * RcppSrc/Rcpp.{cpp,h}: moved to src/ directory * RcppSrc/Makefile{,.win}: removed * inst/doc/RcppAPI.{Rnw,pdf}: Added footnote onto titlepage about how this document has not (yet) been updated along with the channges made Download A local archive is available here and at CRAN; SVN access is provided at R-Forge. Last modified: Tue Dec 2 22:03:43 CST 2008