As per Dirk's suggestion about creating a trivial class, I managed to get
this to work. Thank you for the suggestion Dirk, again sorry if I wasn't
initially clear.
class myEigen {
public:
myEigen(SEXP A_) : A(A_) {}
MatrixXf matrix() {return as<MatrixXf>(A);}
private:
SEXP A;
};
// [[Rcpp::export]]
SEXP matrixIN(SEXP A)
{
myEigen *C = new myEigen(A);
XPtr<myEigen> pMat(C);
return(pMat);
}
// [[Rcpp::export]]
void matrixOUT(XPtr<myEigen> ptrA, int nr, int nc)
{
MatrixXf A = ptrA->matrix();
std::cout << A << std::endl;
}
On Fri, Jun 26, 2015 at 8:54 AM, Charles Determan <cdeterma...@gmail.com>
wrote:
> I apologize if I am not being clear. I realize that R doesn't have float
> data types, however I am able to pass a matrix in as a MatrixXf object. I
> would like to be able to refer to this MatrixXf object persistently. Some
> general code to demonstrate my point.
>
> # pass R matrix in as MatrixXf object and return pointer to that object
> SEXP matrixIN(MatrixXf A)
> {
> return XPtr<MatrixXf>(A);
> }
>
> # pass previously made pointer and return that matrix
> SEXP matrixOUT(XPtr<MatrixXfr> ptrA)
> {
> MatrixXf A = *ptrA
> return wrap(A)
> }
>
> On Fri, Jun 26, 2015 at 8:32 AM, Dirk Eddelbuettel <e...@debian.org> wrote:
>
>>
>> On 26 June 2015 at 07:43, Charles Determan wrote:
>> | I have tried a few more feeble attempts (explicitly create pointer to
>> pass,
>> | passing just the MatrixXf object) at getting the Eigen object to persist
>> | between functions without the additional Armadillo wrapper but with no
>> | success. Anyone have any additional thoughts?
>>
>> You are not making it very easy to help you as you do not clearly say what
>> you really want. Some things you talk about don't exist (ie "float
>> matrix in
>> R"), others make no sense (XPtr of Eigen::Map when the latter already is a
>> proxy object).
>>
>> As for the question of persistence, the single simplest approach I often
>> use
>> it create a trivial class holding a member variable of the "thing" you
>> want
>> to persist (often a database or resource handle, could even be a honking
>> bigmemory object and shared handle) whichI create in the constructor, or
>> an
>> init() function, and release in the destructor.
>>
>> Dirk
>>
>> --
>> http://dirk.eddelbuettel.com | @eddelbuettel | e...@debian.org
>>
>
>
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