c++ how to get eigenvalue what is the purpose of eigen in rcpp arma::vec value what is arma_vec arma::vec eigen_val what is arma's eigenvalue what is the rcpp function a which r function has different results than eigen what r function returns eigenvalues what is arma's function what is the arma function why is eigen different from eigen() what is r eigen what is arma's value value c++ what is the difference between armadillo and eigenvalue why do r function eigen and eigesym give different results rcpp arma what kind of data does r use for arma why does r function eigen vs armel do different c++ eigen values