https://github.com/xlisp/rcpp-algorithms
Rcpp algorithms, Compare R and C++, Interop R and C++, R package develop
https://github.com/xlisp/rcpp-algorithms
cpp r rcpp
Last synced: about 2 months ago
JSON representation
Rcpp algorithms, Compare R and C++, Interop R and C++, R package develop
- Host: GitHub
- URL: https://github.com/xlisp/rcpp-algorithms
- Owner: xlisp
- Created: 2017-10-13T05:42:28.000Z (over 8 years ago)
- Default Branch: master
- Last Pushed: 2017-10-14T05:51:58.000Z (over 8 years ago)
- Last Synced: 2025-05-15T17:14:30.087Z (about 1 year ago)
- Topics: cpp, r, rcpp
- Homepage:
- Size: 9.77 KB
- Stars: 2
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# Rcpp Algorithms, R的快速建模 和 C++无限的资源互操作
* Compare R and C++
* Interop R and C++(使用无限的C++算法库资源,OpenCV,TensorFlow,各种机器学习和深度学习,机器视觉,语音识别算法库)
* R package develop
- [Rcpp Algorithms, R的快速建模 和 C++无限的资源互操作](#rcpp-algorithms-r%E7%9A%84%E5%BF%AB%E9%80%9F%E5%BB%BA%E6%A8%A1-%E5%92%8C-c%E6%97%A0%E9%99%90%E7%9A%84%E8%B5%84%E6%BA%90%E4%BA%92%E6%93%8D%E4%BD%9C)
- [cppFunction & sourceCpp](#cppfunction--sourcecpp)
- [Matrix & Vector](#matrix--vector)
- [C++ 操作 R数值向量](#c-%E6%93%8D%E4%BD%9C-r%E6%95%B0%E5%80%BC%E5%90%91%E9%87%8F)
- [C++ 向量输出`NumericVector outVector(ys.size())`创建一个长度为n的数值向量](#c-%E5%90%91%E9%87%8F%E8%BE%93%E5%87%BAnumericvector-outvectoryssize%E5%88%9B%E5%BB%BA%E4%B8%80%E4%B8%AA%E9%95%BF%E5%BA%A6%E4%B8%BAn%E7%9A%84%E6%95%B0%E5%80%BC%E5%90%91%E9%87%8F)
- [c++操作矩阵, 一层层for操作(就像生成学号一样)](#c%E6%93%8D%E4%BD%9C%E7%9F%A9%E9%98%B5-%E4%B8%80%E5%B1%82%E5%B1%82for%E6%93%8D%E4%BD%9C%E5%B0%B1%E5%83%8F%E7%94%9F%E6%88%90%E5%AD%A6%E5%8F%B7%E4%B8%80%E6%A0%B7)
- [c++ 矩阵输出](#c-%E7%9F%A9%E9%98%B5%E8%BE%93%E5%87%BA)
### cppFunction & sourceCpp
```r
(require (Rcpp))
(cppFunction ('int one() {
return 1;
}'))
(one ()) #=> "[1] 1" 标量输出
```
* fib_cpp_1.cpp
```c++
#include
using namespace Rcpp;
//[[Rcpp::export]]
int fib_cpp_1(int n)
{
if(n==1||n==2) return 1;
return fib_cpp_1(n-1)+fib_cpp_1(n-2);
}
```
```r
> require(Rcpp)
载入需要的程辑包：Rcpp
>
> sourceCpp('fib_cpp_1.cpp')
> fib_cpp_1(50)
[1] -298632863
> fib_cpp_1(10)
[1] 55
> fib_cpp_1(20)
[1] 6765
> fib_cpp_1(30)
[1] 832040
> system.time(fib_cpp_1(50))
用户 系统 流逝
27.053 0.356 28.620
>
```
### Matrix & Vector
##### C++ 操作 R数值向量
```r
(cppFunction ('double sumC(NumericVector x) {
int n = x.size();
double total = 0;
for(int i = 0; i < n; ++i) {
total += x[i];
}
return total;
}'))
(sumC (c (1, 1, 3))) #=> [1] 5
```
##### C++ 向量输出`NumericVector outVector(ys.size())`创建一个长度为n的数值向量
```r
(cppFunction ('NumericVector pdistC(double x, NumericVector ys) {
int n = ys.size();
NumericVector out(n);
for(int i = 0; i < n; ++i) {
out[i] = sqrt(pow(ys[i] - x, 2.0));
}
return out;
}'))
(pdistC (-1, (c (2, 2)))) #=> [1] 3 3
```
##### c++操作矩阵, 一层层for操作(就像生成学号一样)
```r
# x(i, j) c++中用()对矩阵进行子集选取
(cppFunction ('NumericVector rowSumsC(NumericMatrix x) {
int nrow = x.nrow(), ncol = x.ncol();
NumericVector out(nrow);
for (int i = 0; i < nrow; i++) {
double total = 0;
for (int j = 0; j < ncol; j++) {
total += x(i, j);
}
out[i] = total;
}
return out;
}'))
(rowSumsC (matrix ((sample (100)), 10))) #=> [1] 489 515 476 415 547 551 357 663 533 504
```
##### c++ 矩阵输出
```r
(cppFunction ('NumericMatrix zeroMat(int x, int y) {
NumericMatrix outMat(x, y);
return outMat;
}'))
(zeroMat (3, 2))
#=>
[,1] [,2]
[1,] 0 0
[2,] 0 0
[3,] 0 0
```
### 将C++函数和类导出到R中 -> Rcpp Modules
```r
```