fix doxygen and cpplint

Author: SteveBronder

stan/math/mix/functor/laplace_marginal_density_estimator.hpp

@@ -367,10 +367,14 @@ struct NewtonState {
    *
    * When the caller supplies a non-zero theta_init, a_init = Sigma^{-1} *
    * theta_init must be provided to maintain the invariant theta = Sigma * a.
-   *
+   * @tparam ObjFun A callable type for the objective function
+   * @tparam ThetaGradFun A callable type for the theta gradient function
+   * @tparam CovarianceT A matrix type for the covariance (must support LLT solve)
+   * @tparam ThetaInitializer A type for the initial theta (e.g., Eigen vector)
    * @param theta_size Dimension of the latent space
    * @param obj_fun Objective function: (a, theta) -> double
    * @param theta_grad_f Gradient function: theta -> grad
+   * @param covariance Covariance matrix for the latent variables
    * @param a_init Initial a value consistent with theta_init
    * @param theta_init Initial theta value
    */

test/unit/math/laplace/laplace_marginal_density_estimator_test.cpp

@@ -28,7 +28,7 @@ struct QuarticLikelihood {
 struct TinyQuarticLikelihood {
   template <typename Theta>
   auto operator()(const Theta& theta, std::ostream* /*msgs*/) const {
-    return 1e-8 * QuarticLikelihood{}(theta, nullptr);
+    return 1e-8 * QuarticLikelihood{}(theta, nullptr); // NOLINT
   }
 };