Using simcdm in R packages

James Joseph Balamuta

2023-11-29

Package usage

The design of simcdm allows the package to be included in other R packages using either the R or C++ functions. The next section details provides with how to incorporate either the R or C++ functions into a new R package or standalone C++ file.

Note, if you are not familiar with compiled code in R please feel free to use the traditional way to import the R functions.

R Package Usage

To use simcdm’s R functions only in your own R package, modify the package’s DESCRIPTION file by adding an imports declaration.

Imports: simcdm

Inside of the package’s NAMESPACE file, make sure to use:

import(simcdm)

If you are using roxygen2 to manage the packages NAMESPACE file, add the following tag and re-run the roxygenize() function.

#' @import simcdm

C++ Usage

C++ Standalone Usage

Within a C++ file in src/, then add:

#include <RcppArmadillo.h>
#include <simcdm.h>

// [[Rcpp::depends(simcdm, RcppArmadillo)]]

// [[Rcpp::export]]
arma::mat example_dina_sim(const arma::mat &alphas, const arma::mat &Q,
                           const arma::vec &ss, const arma::vec &gs) { 
                           
   arma::mat dina_items = simcdm::sim_dina_items(alphas, Q, ss, gs);
   
   return dina_items;
}

C++ Package

To use C++ functions available in simcdm within your R package, modify your package’s DESCRIPTION file by adding:

LinkingTo: Rcpp, RcppArmadillo (>= 0.9.200), simcdm
Imports:
    Rcpp (>= 1.0.0)

Reference the simulation functions using simcdm namespace like so:

#include <simcdm.h>

// [[Rcpp::export]]
arma::mat example_rrum_sim(const arma::mat &Q, const arma::mat &rstar,
                           const arma::vec &pistar, const arma::mat &alpha) { 
                           
   arma::mat rrum_items = simcdm::sim_rrum_items(Q, rstar, pistar, alpha);
   
   return rrum_items;
}