[Rcpp-devel] Overflow error when creating a large matrix

[Florian Plaza Oñate]

The bug is probably fixed by this commit:
https://github.com/RcppCore/Rcpp/commit/eb069bf5c20aaa4d38e0ca2897bf04e956cb8c4c

Le 31/10/2015 20:08, Alessandro Mammana a écrit :
> Dear All,
> When creating a large matrix with the follwing code:
>
> #include <Rcpp.h>
> // [[Rcpp::export]]
> Rcpp::IntegerMatrix makeMat(int nrow, int ncol){
>          Rcpp::IntegerMatrix mat(nrow, ncol);
>          return mat;
> }
>
> I get the error:
>
> Error in .Primitive(".Call")(<pointer: 0x7f86936d3ea0>, nrow, ncol) :
>    negative length vectors are not allowed
>
> Where nrow*ncol is a very large number (about 3*10^9). I understand
> that such a number cannot be represented by an int type, but this does
> not seem to be a problem when in R I do:
>
>> mat <- matrix(0, nrow=nrow, ncol=ncol)
>
> Questions:
> 1. why is the behaviour different between R and Rcpp in the allocation
> of a matrix?
> 2. In a 64 bits machine, what is actually the maximum allowed length
> of a vector/matrix? does the length of a vector/matrix need to be
> represented by an int?
>
> Thanks a lot and best regards,
> Alessandro
>