Rcpp11 useR2014
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Rcpp11 is a header-only C++ library that targets C++11. It has a smaller code base than Rcpp and allows for faster compilation times due to reduced complexity. Rcpp11 introduces C++11 features like uniform initialization for creating NumericVectors and lambda functions that can be used with sapply. It is available on CRAN but evolves quickly, so the latest version should be installed from GitHub. The attributes package on GitHub contains functions for exporting C++ functions to R using attributes.
![#include <Rcpp.h>
!
// [[Rcpp::export]]
int foo(){
return 2 ;
}
Rcpp
Rcpp11
0 1 2 3 4
Less complexity -> faster compiles](https://image.slidesharecdn.com/rcpp11user-140706102523-phpapp02/85/Rcpp11-useR2014-4-320.jpg)
![create
NumericVector x = {1.0, 2.0, 3.0} ;
!
// old school NumericVector::create (Rcpp style).
NumericVector x = NumericVector::create(1.0, 2.0, 3.0) ;
NumericVector x = NumericVector::create(
_["a"] = 1.0, _["b"] = 2.0, _["c"] = 3.0
) ;
!
!// create as a free function. Rcpp11 style
NumericVector x = create(1.0, 2.0, 3.0) ;
NumericVector x = create(
_["a"] = 1.0, _["b"] = 2.0, _["c"] = 3.0
) ;](https://image.slidesharecdn.com/rcpp11user-140706102523-phpapp02/85/Rcpp11-useR2014-7-320.jpg)
![sugar
#include <Rcpp11>
!
// [[export]]
NumericVector foo( NumericVector x ){
return sqrt(exp(x)) + 1.0 ;
}
!
/*** R
foo( c(1,2,3) )
# [1] 2.648721 3.718282 5.481689
*/](https://image.slidesharecdn.com/rcpp11user-140706102523-phpapp02/85/Rcpp11-useR2014-8-320.jpg)
![sapply + lambda
#include <Rcpp11>
!
// [[export]]
NumericVector foo( NumericVector x ){
return sapply(x, [](double d){
return exp(d * 2) ;
});
}
x <- 1:3
sapply( x, function(d){
exp(d*2) ;
})](https://image.slidesharecdn.com/rcpp11user-140706102523-phpapp02/85/Rcpp11-useR2014-10-320.jpg)
![sapply + lambda + …
#include <Rcpp11>
!
// [[export]]
NumericVector foo( NumericVector x ){
auto fun = [](double d, double y, double z){
return exp(d * y) + z ;
} ;
return sapply(x, fun, 3.0, 4.6);
}
x <- 1:3
sapply( x, function(d, y, z){
exp(d*y) + z ;
}, 3.0, 4.6 )](https://image.slidesharecdn.com/rcpp11user-140706102523-phpapp02/85/Rcpp11-useR2014-11-320.jpg)
![attributes companion package
• Standalone impl of Rcpp attributes
[[Rcpp::export]], sourceCpp, compileAttributes
!
• Only available from github:
> install_github( "Rcpp11/attributes" )](https://image.slidesharecdn.com/rcpp11user-140706102523-phpapp02/85/Rcpp11-useR2014-13-320.jpg)
![Use Rcpp11 in your package
• Write your .cpp files
#include <Rcpp11>
!
// [[export]]
void foo( … ) { … } // your code
SystemRequirements: C++11
LinkingTo: Rcpp11
library(attributes)
compileAttributes( "mypkg" )
• Express dep on C++11 and Rcpp11 headers
• Generate the boiler plate](https://image.slidesharecdn.com/rcpp11user-140706102523-phpapp02/85/Rcpp11-useR2014-14-320.jpg)
Rcpp11 useR2014
- 2. Rcpp11 • Targets C++11 • Smaller code base (than Rcpp) • Header only
- 4. #include <Rcpp.h> ! // [[Rcpp::export]] int foo(){ return 2 ; } Rcpp Rcpp11 0 1 2 3 4 Less complexity -> faster compiles
- 6. NumericVector constructors // C++ uniform initialization NumericVector x = {1.0, 2.0, 3.0} ; ! // init with given size NumericVector y( 2 ) ; // data is not initialized NumericVector y( 2, 3.0 ) ; // initialize all to 3.0 ! // fuse several vectors (similar to c in R) NumericVector z = fuse(x, y) ; NumericVector z = fuse(x, y, 3.0) ;
- 7. create NumericVector x = {1.0, 2.0, 3.0} ; ! // old school NumericVector::create (Rcpp style). NumericVector x = NumericVector::create(1.0, 2.0, 3.0) ; NumericVector x = NumericVector::create( _["a"] = 1.0, _["b"] = 2.0, _["c"] = 3.0 ) ; ! !// create as a free function. Rcpp11 style NumericVector x = create(1.0, 2.0, 3.0) ; NumericVector x = create( _["a"] = 1.0, _["b"] = 2.0, _["c"] = 3.0 ) ;
- 8. sugar #include <Rcpp11> ! // [[export]] NumericVector foo( NumericVector x ){ return sqrt(exp(x)) + 1.0 ; } ! /*** R foo( c(1,2,3) ) # [1] 2.648721 3.718282 5.481689 */
- 10. sapply + lambda #include <Rcpp11> ! // [[export]] NumericVector foo( NumericVector x ){ return sapply(x, [](double d){ return exp(d * 2) ; }); } x <- 1:3 sapply( x, function(d){ exp(d*2) ; })
- 11. sapply + lambda + … #include <Rcpp11> ! // [[export]] NumericVector foo( NumericVector x ){ auto fun = [](double d, double y, double z){ return exp(d * y) + z ; } ; return sapply(x, fun, 3.0, 4.6); } x <- 1:3 sapply( x, function(d, y, z){ exp(d*y) + z ; }, 3.0, 4.6 )
- 12. Rcpp11 release cycle • Available from CRAN: ! • Evolves quickly. Get it from github ! • Next Release: 3.1.1 (same time as R 3.1.1) > install.packages( "Rcpp11" ) > install_github( "Rcpp11/Rcpp11" )
- 13. attributes companion package • Standalone impl of Rcpp attributes [[Rcpp::export]], sourceCpp, compileAttributes ! • Only available from github: > install_github( "Rcpp11/attributes" )
- 14. Use Rcpp11 in your package • Write your .cpp files #include <Rcpp11> ! // [[export]] void foo( … ) { … } // your code SystemRequirements: C++11 LinkingTo: Rcpp11 library(attributes) compileAttributes( "mypkg" ) • Express dep on C++11 and Rcpp11 headers • Generate the boiler plate