Accessing list object in Rcpp using RcppArmadillo.
Create a list object in Rcpp
In Rcpp, you can create a list of object by using List::create() function. The name of element can be created using either Rcpp::Named() or _[].
// Create list L from vector v1, v2
List L = List::create(v1, v2);
// When giving names to elements
List L = List::create(Named("name1") = v1 , _["name2"] = v2);
Accessing the elements in list
You can easily access the element in a list by either using indices or character name.
NumericVector v1 = L[0];
NumericVector v2 = L["V1"];
However, notice that the objects in list are stored in Rcpp::Vector form, therefore, if you are using RcppArmadillo, you need to convert it to arma::mat :
arma::mat v1_mat = as<arma::mat>(L[0]);
arma::mat v2_mat = as<arma::mat>(L["V1"]);