根据示例代码,我试图使用c++
和RInside
运行预测方法,但是我正在获取Read 100 items Exception caught: not a matrix
有人可以看看我的代码吗?
#include <RInside.h>
int main ( int argc, char **argv) {
try {
// create an embedded R instance
RInside R ( argc, argv);
std::string txt =
"rain <- scan(\"http://robjhyndman.com/tsdldata/hurst/precip1.dat\",skip=1);"
"rainseries <- ts(rain,start=c(1813));"
"rainseriesforecasts <- HoltWinters(rainseries, beta=FALSE, gamma=FALSE);"
"suppressMessages(require(forecast));";
R.parseEvalQ(txt); // eval command, no return
Rcpp::NumericMatrix M((SEXP)R.parseEval("rainseriesforecasts2 <- forecast.HoltWinters(rainseriesforecasts, h=8)"));
Rcpp::StringVector cnames( (SEXP) R.parseEval("colnames(rainseriesforecasts2)"));
Rcpp::StringVector rnames( (SEXP) R.parseEval("rownames(rainseriesforecasts2)"));
std::cout << "\n\nAnd now from C++\n\n\t\t\t";
for (int i=0; i<cnames.size(); i++) {
std::cout << std::setw(11) << cnames[i] << "\t";
}
std::cout << std::endl;
for (int i=0; i<rnames.size(); i++) {
std::cout << std::setw(16) << rnames[i] << "\t";
for (int j=0; j<cnames.size(); j++) {
std::cout << std::setw(11) << M(i,j) << "\t";
}
std::cout << std::endl;
}
std::cout << std::endl;
} catch(std::exception& ex) {
std::cerr << "Exception caught: " << ex.what() << std::endl;
} catch(...) {
std::cerr << "Unknown exception caught" << std::endl;
}
}
最佳答案
这看起来像是我在RInside源代码中包含的十几个示例之一的直接改编版-因此这是一个很好的起点。
您引用的错误是R错误,而不是C++错误,因此我将首先尝试在R中自己尝试几行R代码。请特别注意要分配的返回值的class()
,以确保您进行了强制转换正确的C++类型。
编辑:好的,有一些时间来看看它。您很亲密,但是由于我怀疑forecast
包中的类型妨碍了您。尝试这个:
R.parseEvalQ(txt); // eval command, no return
Rcpp::NumericMatrix M((SEXP)R.parseEval("rainseriesforecasts2 <- as.matrix(as.data.frame(forecast.HoltWinters(rainseriesforecasts, h=8)))"));
Rcpp::StringVector cnames( (SEXP) R.parseEval("colnames(as.data.frame(rainseriesforecasts2))"));
Rcpp::StringVector rnames( (SEXP) R.parseEval("rownames(as.data.frame(rainseriesforecasts2))"));
并为我工作:
edd@dexter:~/svn/rinside/pkg/inst/examples/standard$ ./rinside_sample12
Read 100 items
And now from C++
Point Forecast Lo 80 Hi 80 Lo 95 Hi 95
1913 24.6782 19.1749 30.1815 16.2617 33.0947
1914 24.6782 19.1733 30.1831 16.2592 33.0972
1915 24.6782 19.1717 30.1847 16.2568 33.0996
1916 24.6782 19.1701 30.1863 16.2543 33.102
1917 24.6782 19.1685 30.1879 16.2519 33.1045
1918 24.6782 19.1669 30.1895 16.2495 33.1069
1919 24.6782 19.1653 30.1911 16.247 33.1094
1920 24.6782 19.1637 30.1926 16.2446 33.1118
edd@dexter:~/svn/rinside/pkg/inst/examples/standard$
关于c++ - Forecast.HoltWinters没有映射到C++,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/9720317/