I want to use Rcpp to make certain parts of my code more efficient. I have a main R function in which my objects are defined, in this R functions I have several rcpp functions that use the r data objects as inputs. This is one example of an rcpp function that is called in the R-function:
void calculateClusters ( List order,
NumericVector maxorder,
List rank,
double lambda,
int nbrClass,
NumericVector nbrExamples) {
int current, i;
for ( current = 0; current < nbrClass; current ++ ) {
maxorder [current] = 0;
for ( i = 0; i < nbrExamples [ current ]; i++ ) {
order[ current ][i] = ( int ) ( rank[ current ][i] / lambda ) - 1;
}
if ( order[ current ][i] > maxorder[ current ] ) {
maxorder[ current ] = order[ current ][i];
}
}
}
This function calculates the maximum number of clusters for each class. In native c++ coding I would define my List as an int** and my NumericVector as int*. However in Rcpp this gives an error. I know the fault lies in the subsetting of these Lists (I handled them the same way as int**).
My question is how can I transform these int** succesfully into List, without loosing flexibility. For example the List order and distance have the structure order[[1]][1:500], order[[2]][1:500], so this would be exactly the same as int** in c++ where it would be order[1][1:500], order[2][1:500]. If there are 3 classes the order and the distance List change to order order[[1]][1:500], order[[2]][1:500], order[[3]][1:500]. How can I do this in Rcpp?
