在构建R包时从另一个Rcpp函数调用Rcpp函数

I took this example from a different question. I am building an R package with Rcpp. I have a function like fun1 (below) that I want to put into its own .cpp file. Then I want to call fun1 with other functions (like fun() does below). I want fun1 in a separate file because I am going to call it from several Rcpp functions that are in different .cpp files. Are there certain include statements and things I need to do to make the fun1 function accessible in the .cpp where fun() is located? Thank you.

我从另一个问题中拿了这个例子。我正在用Rcpp构建一个R包。我有一个像fun1(下面)这样的函数,我想将它放入自己的.cpp文件中。然后我想用其他函数调用fun1(如下面的fun())。我想在另一个文件中使用fun1,因为我将从不同.cpp文件中的几个Rcpp函数调用它。是否有某些include语句和我需要做的事情才能使func函数在.cpp中可以访问fun()所在的位置?谢谢。

library(inline)
library(Rcpp)
a = 1:10
cpp.fun = cxxfunction(signature(data1="numeric"), 
                  plugin="Rcpp",
                  body="
int fun1( int a1)
{int b1 = a1;
 b1 = b1*b1;
 return(b1);
}

NumericVector fun_data  = data1;
int n = data1.size();
for(i=0;i<n;i++){
fun_data[i] = fun1(fun_data[i]);
}
return(fun_data);
                           ")

So for my code I will have two .cpp files:

所以对于我的代码,我将有两个.cpp文件:

#include <Rcpp.h>
using namespace Rcpp;
// I think I need something here to make fun1.cpp available?

// [[Rcpp::export]]
Rcpp::NumericVector fun(Rcpp::NumericVector data1) 
{ 
    NumericVector fun_data  = data1;
    int n = data1.size();
    for(i=0;i<n;i++){
    fun_data[i] = fun1(fun_data[i]);
    }
    return(fun_data);
}

And a second .cpp file:

第二个.cpp文件:

#include <Rcpp.h>
using namespace Rcpp;

// [[Rcpp::export]]
int fun1( int a1)
{int b1 = a1;
 b1 = b1*b1;
 return(b1);
}

1 个解决方案

#1

Two possible solutions:

两种可能的方案:

The 'quick-and-dirty', solution -- include the function declaration in the file where you use it:

“快速而肮脏”的解决方案 - 在您使用它的文件中包含函数声明:

#include <Rcpp.h>
using namespace Rcpp;

// declare fun1
int fun1(int a1);

// [[Rcpp::export]]
Rcpp::NumericVector fun(Rcpp::NumericVector data1) 
{ 
    NumericVector fun_data  = data1;
    int n = data1.size();
    for(i=0;i<n;i++){
    fun_data[i] = fun1(fun_data[i]);
    }
    return(fun_data);
}

The more robust solution: write header files that declare the functions, which can then be #include-ed in each file. So you might have a header file fun1.h in the same src directory:

更强大的解决方案:编写声明函数的头文件,然后可以在每个文件中#include-ed。所以你可能在同一个src目录中有一个头文件fun1.h:

#ifndef PKG_FOO1_H
#define PKG_FOO1_H

int foo(int);

#endif

which you could then use with something like:

您可以使用以下内容:

#include <Rcpp.h>
#include "fun1.h"
using namespace Rcpp;

// [[Rcpp::export]]
Rcpp::NumericVector fun(Rcpp::NumericVector data1) 
{ 
    NumericVector fun_data  = data1;
    int n = data1.size();
    for(i=0;i<n;i++){
    fun_data[i] = fun1(fun_data[i]);
    }
    return(fun_data);
}

As you progress, you're going to need to learn more C++ programming skills, so I recommend checking out one of the books here; in particular, Accelerated C++ is a great introduction.

随着您的进步,您将需要学习更多的C ++编程技能,因此我建议您查看其中一本书;特别是,Accelerated C ++是一个很好的介绍。

#1