How to get Rcpp to work? - r

Question

I cannot get Rcpp to work on Windows 8.1. When I run the following minimal example, I get an error.
> library(Rcpp)
> evalCpp("1 + 1")
g++ -m64 -I"C:/R/R-31~1.0/include" -DNDEBUG -I"C:/R/R-3.1.0/library/Rcpp/include" -
I"d:/RCompile/CRANpkg/extralibs64/local/include" -O2 -Wall -mtune=core2 -c file11dc2120723d.cpp -o
file11dc2120723d.o g++: not found make: *** [file11dc2120723d.o] Error 127 Warning message: running
command 'make -f "C:/R/R-31~1.0/etc/x64/Makeconf" -f "C:/R/R-31~1.0/share/make/winshlib.mk"
SHLIB_LDFLAGS='$(SHLIB_CXXLDFLAGS)' SHLIB_LD='$(SHLIB_CXXLD)' SHLIB="sourceCpp_97232.dll" WIN=64 TCLBIN=64
OBJECTS="file11dc2120723d.o"' had status 2
Error in sourceCpp(code = code, env = env, rebuild = rebuild, showOutput = showOutput, :
Error 1 occurred building shared library.
The two first entries in my path are:
PATH=c:\Rtools\bin;c:\Rtools\gcc-4.6.3\bin;
R is installed in a directory C:\R\R-3.1.0
Rtools is in the directory C:\R\Rtools
Some additional information:
> library(devtools)
> find_rtools(T)
Scanning path...
ls : c:\Rtools\bin\ls.exe
Scanning registry...
Found c:/Rtools for 3.1
VERSION.txt
Rtools version 3.1.0.1942
[1] TRUE
> has_devel()
"C:/R/R-31~1.0/bin/x64/R" --vanilla CMD SHLIB foo.c
gcc -m64 -I"C:/R/R-31~1.0/include" -DNDEBUG -I"d:/RCompile/CRANpkg/extralibs64/local/include"
O2 -Wall -std=gnu99 -mtune=core2 -c foo.c -o foo.o
gcc: not found
make: *** [foo.o] Error 127
Warning message:
running command 'make -f "C:/R/R-31~1.0/etc/x64/Makeconf" -f "C:/R/R-31~1.0/share/make/winshlib.mk"
SHLIB="foo.dll" WIN=64 TCLBIN=64 OBJECTS="foo.o"' had status 2
Error: Command failed (1)
> system('g++ -v')
Warning message:
running command 'g++ -v' had status 127

Answer 1

Unsure if you have solved your problem but it appears you don't have gcc or g++ installed. For windows you can get these tools with MinGW.
Install MinGW which you can donwload from here. The homepage for information is here
Once you have it installed MinGW, you can open the 'MinGW Installation Manager' and install the bin and dev for 'mingw32-gcc-g++'.
You must then update your PATH environmental variable to include 'C:\MinGW\bin' and 'C:\MinGW\msys\1.0\bin'.
Restart your R session, couldn't hurt to also reinstall 'Rcpp', and tryrequire(Rcpp); evalCpp("1 + 1") again.

Answer 2

I had this problem while trying to call C-code directly. Switching from the function system() to system2() solved it immediately.

Answer 3

I got that fix by installing RTools and adding RBuildTools to the path:
Sys.setenv("PATH" = paste(Sys.getenv("PATH"),
"C:\\RBuildTools\\3.4\\bin",
"C:\\RBuildTools\\3.4\\mingw_32",
"C:\\RBuildTools\\3.4\\mingw_64", sep = ";"))
I don't understand these things clearly but #cdeterman solutions was not working for building my package while its example evalCpp("1 + 1") did.