I’ve recently downloaded Stan from github and I’m trying to use the automatic differentiation package. However, on including the header <stan/math.hpp>, I get the following error:
/Users/hannesvdc/math/stan/math/rev/fun/dot_product.hpp:43:16: error: no member named 'val' in 'Eigen::Map<Eigen::Matrix<stan::math::vari *, -1, 1, 0, -1, 1>, 0, Eigen::Stride<0, 0> >' return vd1.val().dot(vd2.val());
I have the latest version of Eigen (3.3.7) installed on my mac (OSX Catalina 10.15.2). When I look at the eigen code, the object Eigen::Map does indeed not possess a member ‘val’.
Has anyone had this issue before?