Hi again,
Here is an example:
my c++ file:
// [[Rcpp::depends(RcppArmadillo)]]
#include <RcppArmadillo.h>
#include <Rcpp.h>
using namespace Rcpp ;
using namespace arma ;
using namespace std ;
// [[Rcpp::export]]
uvec touvec(const uvec& v) {
return v;
}
Save to "example.cpp" and call the following in R-console:
Rcpp::sourceCpp('example.cpp')
[,1]
[1,] 0
[2,] 1072693248
[3,] 0
[4,] 1073741824
[5,] 0
[6,] 1074266112
[7,] 0
[8,] 1074790400
[9,] 0
[10,] 1075052544
Best,
Venelin
2014-04-20 15:34 GMT+02:00 Dirk Eddelbuettel <edd at debian.org>:
Hi Venelin,
On 20 April 2014 at 15:18, Venelin Mitov wrote:
| Hello,
|
| I have a dynamic library with C++ functions built using Rcpp. I've
recently
| updated to the newest version of R/Rcpp/RcppArmadillo and after
rebuilding my
| library it lost its expected behavior. After some debugging I found
that one of
| possibly several problems is the following:
|
| I have an exported cpp function with the following signature:
| uvec shift(const uvec& idx, int dshift, int n, int i=1);
|
| In my R-code I call this function as follows:
| shifted_idx <- shift(1:10, 5, 10, 1).
| This is a detail, but let me mension that all this function does is to
rotate
| the vector of indices idx left by 5 positions, so the result should be
the
| vector: c(6,7,8,9,10,1,2,3,4,5).
|
| This is the wrapper for the same function generated with the older
| Rcpp-version:
| RcppExport SEXP sourceCpp_28368_shift(SEXP idxSEXP, SEXP dshiftSEXP,
SEXP
| nSEXP, SEXP iSEXP) {
| BEGIN_RCPP
| SEXP __sexp_result;
| {
| Rcpp::RNGScope __rngScope;
| uvec idx = Rcpp::as<uvec >(idxSEXP);
| int dshift = Rcpp::as<int >(dshiftSEXP);
| int n = Rcpp::as<int >(nSEXP);
| int i = Rcpp::as<int >(iSEXP);
| uvec __result = shift(idx, dshift, n, i);
| PROTECT(__sexp_result = Rcpp::wrap(__result));
| }
| UNPROTECT(1);
| return __sexp_result;
| END_RCPP
| }
|
| This is the wrapper for this function generated with the newer
Rcpp-version:
| RcppExport SEXP sourceCpp_85322_shift(SEXP idxSEXP, SEXP dshiftSEXP,
SEXP
| nSEXP, SEXP iSEXP) {
| BEGIN_RCPP
| SEXP __sexp_result;
| {
| Rcpp::RNGScope __rngScope;
| Rcpp::traits::input_parameter< const uvec& >::type idx(idxSEXP
);
| Rcpp::traits::input_parameter< int >::type dshift(dshiftSEXP );
| Rcpp::traits::input_parameter< int >::type n(nSEXP );
| Rcpp::traits::input_parameter< int >::type i(iSEXP );
| uvec __result = shift(idx, dshift, n, i);
| PROTECT(__sexp_result = Rcpp::wrap(__result));
| }
| UNPROTECT(1);
| return __sexp_result;
| END_RCPP
| }
|
| The result is that the converted array idx in the newer version has
apparently
| different values than the the passed argument which is simply 1:10. If,
for
| debugging purpose, I modify the function to simply return its first
argument
| this is the value I'm getting:
|
|
| > shift(1:10,5,10,1)
| [,1]
| [1,] 0
| [2,] 1072693248
| [3,] 0
| [4,] 1073741824
| [5,] 0
| [6,] 1074266112
| [7,] 0
| [8,] 1074790400
| [9,] 0
| [10,] 1075052544
|
|
| I'm running this on a 64 bit computer and I could reproduce it on
Ubuntu as well.
|
| I guess that this behaviour is wrong.
|
| To check versions, here is the output of sessionInfo():
|
| R version 3.0.1 (2013-05-16)
| Platform: x86_64-w64-mingw32/x64 (64-bit)
|
| locale:
| [1] LC_COLLATE=English_United States.1252 LC_CTYPE=English_United
States.1252
| [3] LC_MONETARY=English_United States.1252 LC_NUMERIC=C
| [5] LC_TIME=English_United States.1252
|
| attached base packages:
| [1] stats graphics grDevices utils datasets methods base
|
| other attached packages:
| [1] Rcpp_0.11.1
|
| loaded via a namespace (and not attached):
| [1] RcppArmadillo_0.4.200.0 tools_3.0.1
It is entirely possible that something is wrong, and while you provided an
appreciable level of detail, you have not provided a small,
self-contained,
reproducible piece of code.
That would help.
Below are two conversions from Armadillo 'uvec' and 'ivec'. They work
for me.
R> cppFunction("SEXP uvec(int n) { arma::uvec v =
arma::conv_to<arma::uvec>::from(arma::ones(n)); return(wrap(v)); }",
depends="RcppArmadillo")
R> uvec(3)
[,1]
[1,] 1
[2,] 1
[3,] 1
R> cppFunction("SEXP ivec(int n) { arma::ivec v =
arma::conv_to<arma::ivec>::from(arma::ones(n)); return(wrap(v)); }",
depends="RcppArmadillo")
R> ivec(3)
[,1]
[1,] 1
[2,] 1
[3,] 1
R>
In both cases I use ones() to generate (double-valued) vector which I cast
using Armadillo's converter function. The resulting integer, and unsigned
integer, vectors are then converted via wrap(). In both cases do the
correct
values appear.
I probably missed a key aspect of your bug report. Can you provide a
simple example?
Thanks!
Dirk
|
|
| Best,
|
| Venelin
|
|
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--
Dirk Eddelbuettel | edd at debian.org | http://dirk.eddelbuettel.com