On 31 October 2011 at 21:14, andre zege wrote:
| Hi everybody, my apologies in advance if i missed something obvious in
| documentation or misinterpreted things. I started experimenting with Rcpp
| modules and it seems to do in simpler cases exactly what i need. However, I am
| stuck on something that is probably very common
|
| I am using the class for which constructor has 11 parameters, some of which
are
| pointers to doubles.
|
| Strategy s(double *, double *, double *, double *, double *, int, int, int,
| double, double, double)
|
| Pointers point to memory containing matrices that armadillo code inside the
| class Strategy works works with. According to what i read in rcpp module docs,
| a class could be defined in rcpp module only if constructor has six or less
Can you nest it? Just define a new
class StrategyParameters {
private:
int a,b,c,d,e;
double f,g,h,i,j,k};
public:
// some getters/setters and ctors as needed
}
and pass that one? Counts as just one...
| parameters. So it seems that the only way for me to use the class from R is to
| write a Rcpp function that would get called from R with a signature
|
| RcppExport void helper(SEXP, SEXP, ...., SEXP){
|
| //convert input parameters
|
|
| Strategy s(....);
|
| //do whatever needs to be done in Strategy
|
| }
|
| and call constructor within C++ code and then return to R. Is this the best
| way to use Rcpp things in my circumstance?
|
|
| Also, if i take this approach, how would I pass pointers to double to a C++
| constructor? It seems i need to convert SEXP that i receive from R to double *
| in Rcpp framework -- it seems that as<>() template wouldn't convert to a
| pointer. I could use of course .C interface, but i wanted to use Rcpp for a
| number of C++ classes in a uniform way, regardless of the number of
| parameters in the constructor.
Modern C++ style mostly aims to avoid pointers like that. You probably meant
a double array passed as a pointer, a there a std::vector<double> is almost
always preferable.
Dirk
--
"Outside of a dog, a book is a man's best friend. Inside of a dog, it is too
dark to read." -- Groucho Marx
_______________________________________________
Rcpp-devel mailing list
Rcpp-devel@lists.r-forge.r-project.org
https://lists.r-forge.r-project.org/cgi-bin/mailman/listinfo/rcpp-devel
