Learn R Programming

inline (version 0.3.10)

cxxfunction: inline C++ function

Description

Functionality to dynamically define an R function with inlined C++ code using the .Call calling convention.

The rcpp() wrapper sets the plugin to the Rcpp value suitable for using Rcpp.

Usage

cxxfunction(sig = character(), body = character(), 
	plugin = "default", includes = "", 
	settings = getPlugin(plugin), ..., verbose = FALSE)
rcpp(...)

Arguments

sig
Signature of the function. A named character vector
body
A character vector with C++ code to include in the body of the compiled C++ function
plugin
Name of the plugin to use. See getPlugin for details about plugins.
includes
User includes, inserted after the includes provided by the plugin.
settings
Result of the call to the plugin
...
Further arguments to the plugin
verbose
verbose output

Value

  • A function

See Also

cfunction

Examples

Run this code
# default plugin
fx <- cxxfunction( signature(x = "integer", y = "numeric" ) , '
	return ScalarReal( INTEGER(x)[0] * REAL(y)[0] ) ;
' )
fx( 2L, 5 )

# Rcpp plugin
if( require( Rcpp ) ){

	fx <- cxxfunction( signature(x = "integer", y = "numeric" ) , '
		return wrap( as<int>(x) * as<double>(y) ) ;
	', plugin = "Rcpp" )
	fx( 2L, 5 )

        ## equivalent shorter form using rcpp()
	fx <- rcpp(signature(x = "integer", y = "numeric"),
                   ' return wrap( as<int>(x) * as<double>(y) ) ; ')

}

# RcppArmadillo plugin
if( require( RcppArmadillo ) ){
	
	fx <- cxxfunction( signature(x = "integer", y = "numeric" ) , '
		int dim = as<int>( x ) ;
		arma::mat z = as<double>(y) * arma::eye<arma::mat>( dim, dim ) ;
		return wrap( arma::accu(z) ) ;
	', plugin = "RcppArmadillo" )
	fx( 2L, 5 )
	
	
}

Run the code above in your browser using DataLab