cxxfunction: inline C++ function

In inline: Functions to Inline C, C++, Fortran Function Calls from R

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(..., plugin="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

## Not run: 
# default plugin
fx <- cxxfunction(signature(x = "integer", y = "numeric"), 
	          "return ScalarReal(INTEGER(x)[0] * REAL(y)[0]);")
fx(2L, 5)

# Rcpp plugin
if (requireNamespace("Rcpp", quietly=TRUE)) {

    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 (requireNamespace(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)
}

## End(Not run)

inline documentation built on May 31, 2021, 9:08 a.m.