Enable ARMA_64BIT_WORD in RcppArmadillo

Question

I am developing an R package. I have the error message Error: Mat::init(): requested size is too large; suggest to enable ARMA_64BIT_WORD when the input matrix is very large.

I followed the suggestion here, but then I have an error message during the compilation on my C++ code.

I modified my C++ code as described here:

#define R_NO_REMAP
#include <map>
#include <vector>
#include <iostream>
#include <stream>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>

#include "ANN/ANN.h"        // ANN library header
#include "NN.h"             // ANN library header
#include <R.h>              // R header

#define ARMA_64BIT_WORD 1
#include <RcppArmadillo.h>

#define Malloc(type,n) (type *)malloc((n)*sizeof(type))

#ifdef _OPENMP
#include <omp.h>
#endif
#include <cstdlib>

using namespace std;
using namespace Rcpp;


// [[Rcpp::depends(RcppArmadillo)]]
// [[Rcpp::plugins(cpp11)]] 

// [[Rcpp::export]]

and the /src/Makevars{.win} for a package use:

PKG_CPPFLAGS=-I. -IANN -DRANN -DARMA_64BIT_WORD=1
PKG_LIBS = $(LAPACK_LIBS) $(BLAS_LIBS) $(FLIBS) 

Answer 1

Yes, the solution of hbrerkere works perfectly.

You're defining ARMA_64BIT_WORD twice. First in the C++ code, and again in the Makevars file. Use either the first or the second one, but not both.

I had to modify additionally the code.

Previously my code had:

   arma::ivec Ytrain
   ...
   int *label=Ytrain.memptr();

I had to modify as following:

   arma::ivec Ytrain
   ...
   long long int *label=Ytrain.memptr();