The error message is:
"Error in compileCode(f, code, language = language, verbose = verbose) :
Compilation ERROR, function(s)/method(s) not created! In file included from /home/leandro/R/x86_64-pc-linux-gnu-library/3.5/RcppEigen/include/Eigen/Core:388,
from /home/leandro/R/x86_64-pc-linux-gnu-library/3.5/RcppEigen/include/Eigen/Dense:1,
from /home/leandro/R/x86_64-pc-linux-gnu-library/3.5/StanHeaders/include/stan/math/prim/mat/fun/Eigen.hpp:4,
from /home/leandro/R/x86_64-pc-linux-gnu-library/3.5/StanHeaders/include/stan/math/rev/mat/fun/Eigen_NumTraits.hpp:4,
from /home/leandro/R/x86_64-pc-linux-gnu-library/3.5/StanHeaders/include/stan/math/rev/core/matrix_vari.hpp:4,
from /home/leandro/R/x86_64-pc-linux-gnu-library/3.5/StanHeaders/include/stan/math/rev/core.hpp:14,
from /home/leandro/R/x86_64-pc-linux-gnu-library/3.5/StanHeaders/include/stan/math/rev/mat.hpp:4,
from /home/leandro/R/x86_64-pc-linux-gnu-library/3.5/StanHeaders/include/stan/math.hpp:4,
I have been searching in the site, and the problem seems to be in the “sqrt(N - 1)” expression as noted here. Written as “sqrt(N - 1.0)” the code is running now.