Estou trabalhando no livro "Integração perfeita de R e C ++ com Rcpp". Estou usando o R versão 3.1.0 no Ubuntu 12.04. Não consigo descobrir como vincular corretamente as bibliotecas necessárias. Eu tenho o seguinte código em R:

R> library(Rcpp)
R> library(RcppArmadillo)
R> suppressMessages(require(inline))
R> code <- '
+   arma::mat coeff = Rcpp::as<arma::mat>(a);
+   arma::mat errors = Rcpp::as<arma::mat>(u);
+   int m = errors.n_rows;
+   int n = errors.n_cols;
+   arma::mat simdata(m,n);
+   simdata.row(0) = arma::zeros<arma::mat>(1, n);
+   for (int row=1; row < m; row++) {
+     simdata.row(row) = simdata.row(row-1)*trans(coeff)
+                        + errors.row(row);
+   }
+   return Rcpp::wrap(simdata);
+ '
R> rcppSim <- cxxfunction(signature(a="numeric", u="numeric"),
+                        code, plugin="RcppArmadillo")
/usr/bin/ld: cannot find -lgfortran
collect2: error: ld returned 1 exit status
make: *** [file167d1a7cd1ad.so] Error 1

ERROR(s) during compilation: source code errors or compiler configuration errors!

Program source:
1: 
2: // includes from the plugin
3: #include <RcppArmadillo.h>
4: #include <Rcpp.h>
5: 
6: 
7: #ifndef BEGIN_RCPP
8: #define BEGIN_RCPP
9: #endif
10: 
11: #ifndef END_RCPP
12: #define END_RCPP
13: #endif
14: 
15: using namespace Rcpp;
16: 
17: 
18: // user includes
19: 
20: 
21: // declarations
22: extern "C" {
23: SEXP file167d1a7cd1ad( SEXP a, SEXP u) ;
24: }
25: 
26: // definition
27: 
28: SEXP file167d1a7cd1ad( SEXP a, SEXP u ){
29: BEGIN_RCPP
30: 
31:   arma::mat coeff = Rcpp::as<arma::mat>(a);
32:   arma::mat errors = Rcpp::as<arma::mat>(u);
33:   int m = errors.n_rows;
34:   int n = errors.n_cols;
35:   arma::mat simdata(m,n);
36:   simdata.row(0) = arma::zeros<arma::mat>(1, n);
37:   for (int row=1; row < m; row++) {
38:     simdata.row(row) = simdata.row(row-1)*trans(coeff)
39:                        + errors.row(row);
40:   }
41:   return Rcpp::wrap(simdata);
42: 
43: END_RCPP
44: }
45: 
46: 
Error in compileCode(f, code, language = language, verbose = verbose) : 
Compilation ERROR, function(s)/method(s) not created! 
/usr/bin/ld: cannot find -lgfortran
collect2: error: ld returned 1 exit status
make: *** [file167d1a7cd1ad.so] Error 1
Calls: cxxfunction -> compileCode
In addition: Warning message:
running command '/usr/lib/R/bin/R CMD SHLIB file167d1a7cd1ad.cpp 2>  
file167d1a7cd1ad.cpp.err.txt' had status 1 

Com base nesta resposta a uma pergunta semelhante,

http://lists.r-forge.r-project.org/pipermail/rcpp-devel/2014-February/007245.html

parece que eu simplesmente preciso instalar o compilador FORTRAN. No entanto, eu instalei o gfortran usando o gerenciador de pacotes Ubuntu e ainda recebo o mesmo erro. Do terminal:

$ dpkg -s gfortran
Package: gfortran
Status: install ok installed
Priority: optional
Section: devel
Installed-Size: 33
Maintainer: Ubuntu Developers <[email protected]>
Architecture: i386
Source: gcc-defaults (1.112ubuntu5)
Version: 4:4.6.3-1ubuntu5
Provides: fortran-compiler
Depends: cpp (>= 4:4.6.3-1ubuntu5), gcc (>= 4:4.6.3-1ubuntu5), gfortran-4.6 
(>=   4.6.3-1~)
Suggests: gfortran-multilib, gfortran-doc
Description: GNU Fortran 95 compiler
This is the GNU Fortran 95 compiler, which compiles Fortran 95 on platforms
supported by the gcc compiler. It uses the gcc backend to generate optimized
code.

This is a dependency package providing the default GNU Fortran 95 compiler.
Original-Maintainer: Debian GCC Maintainers <[email protected]>

Também não consegui usar as funções CxxFlags () e LdFlags (). Todas as sugestões são muito apreciadas.

A execução de sourceCpp () produz o seguinte:

R> rcppSim <- sourceCpp("~/Dropbox/Rcpp/rcppSim.cpp")
rcppSim.cpp: In function ‘SEXPREC* file167d1a7cd1ad(SEXP, SEXP)’:
rcppSim.cpp:31:1: error: ‘arma’ has not been declared
rcppSim.cpp:31:11: error: expected ‘;’ before ‘coeff’
rcppSim.cpp:32:1: error: ‘arma’ has not been declared
rcppSim.cpp:32:11: error: expected ‘;’ before ‘errors’
rcppSim.cpp:33:9: error: ‘errors’ was not declared in this scope
rcppSim.cpp:35:1: error: ‘arma’ has not been declared
rcppSim.cpp:35:11: error: expected ‘;’ before ‘simdata’
rcppSim.cpp:36:1: error: ‘simdata’ was not declared in this scope
rcppSim.cpp:36:18: error: ‘arma’ has not been declared
rcppSim.cpp:36:30: error: ‘arma’ has not been declared
rcppSim.cpp:38:47: error: ‘coeff’ was not declared in this scope
rcppSim.cpp:38:52: error: ‘trans’ was not declared in this scope
make: *** [rcppSim.o] Error 1
g++ -I/usr/share/R/include -DNDEBUG    -I"/usr/lib/R/library/Rcpp/include"
-I"/usr/lib/R/library/RcppArmadillo/include" -I"/usr/lib/R/library/Rcpp/include"     
-fpic  -g -O2 -fstack-protector --param=ssp-buffer-size=4 -Wformat -Wformat-security   
-Werror=format-security -D_FORTIFY_SOURCE=2 -g  -c rcppSim.cpp -o rcppSim.o 
Error in sourceCpp("~/Dropbox/Rcpp/rcppSim.cpp") : 
Error 1 occurred building shared library.

A execução do comando dpkg fornece:

~$ dpkg -l | grep libgfortran | cut -c-75
ii  libgfortran-4.7-dev                          4.7.3-2ubuntu1~12.04      
ii  libgfortran-4.8-dev                          4.8.1-2ubuntu1~12.04      
ii  libgfortran3                                 4.8.1-2ubuntu1~12.04      
~$