Applying suggested changes from review (Issue #2881)

stan-dev · Mar 15, 2020 · 7582cce · 7582cce
1 parent 45fff72
commit 7582cce
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Showing 3 changed files with 6 additions and 5 deletions.
diff --git a/src/stan/mcmc/hmc/hamiltonians/dense_e_point.hpp b/src/stan/mcmc/hmc/hamiltonians/dense_e_point.hpp
@@ -47,7 +47,7 @@ class dense_e_point : public ps_point {
    *
    * @return reference to the inverse metric
    */
-  const Eigen::MatrixXd& get_inv_metric() {
+  const Eigen::MatrixXd& get_inv_metric() const {
     return inv_e_metric_;
   }
 
@@ -57,7 +57,7 @@ class dense_e_point : public ps_point {
    *
    * @return reference to transpose of Cholesky factor
    */
-  const Eigen::MatrixXd& get_transpose_llt_inv_metric() {
+  const Eigen::MatrixXd& get_transpose_llt_inv_metric() const {
     return inv_e_metric_llt_matrixU_;
   }
 

diff --git a/src/stan/mcmc/hmc/hamiltonians/diag_e_metric.hpp b/src/stan/mcmc/hmc/hamiltonians/diag_e_metric.hpp
@@ -45,8 +45,9 @@ class diag_e_metric : public base_hamiltonian<Model, diag_e_point, BaseRNG> {
     boost::variate_generator<BaseRNG&, boost::normal_distribution<> >
         rand_diag_gaus(rng, boost::normal_distribution<>());
 
-    for (int i = 0; i < z.p.size(); ++i)
-      z.p(i) = rand_diag_gaus() / sqrt(z.get_inv_metric()(i));
+    z.p = z.get_inv_metric().unaryExpr([&](auto&& x) {
+	return rand_diag_gaus() / sqrt(x);
+      });
   }
 };
 

diff --git a/src/stan/mcmc/hmc/hamiltonians/diag_e_point.hpp b/src/stan/mcmc/hmc/hamiltonians/diag_e_point.hpp
@@ -42,7 +42,7 @@ class diag_e_point : public ps_point {
    *
    * @return reference to the inverse metric
    */
-  const Eigen::VectorXd& get_inv_metric() {
+  const Eigen::VectorXd& get_inv_metric() const {
     return inv_e_metric_;
   }