diff --git a/src/capture_laser_2D.cpp b/src/capture_laser_2D.cpp
index d6255c7e2f054e373b127d4d07e8b8d41671a8e2..d6ebf859581a054b02f59403fe6a269ab3224c08 100644
--- a/src/capture_laser_2D.cpp
+++ b/src/capture_laser_2D.cpp
@@ -284,7 +284,7 @@ WolfScalar CaptureLaser2D::computeMahalanobisDistance(const FeatureBase* _featur
         // Feature-Landmark Mahalanobis distance
         // covariance: Eigen::Matrix3s S_m = J * Sigma.selfadjointView<Eigen::Upper>() * J.transpose() + _feature_ptr->getMeasurementCovariance().topLeftCorner<3,3>();
         WolfScalar mahalanobis_distance = d_euclidean.transpose() * (J.transpose() * Sigma.selfadjointView<Eigen::Upper>() * J + _feature_ptr->getMeasurementCovariance().topLeftCorner<3,3>()).inverse() * d_euclidean;
-        std::cout << "mahalanobis_distance = " << mahalanobis_distance << std::endl;
+        //std::cout << "mahalanobis_distance = " << mahalanobis_distance << std::endl;
         return mahalanobis_distance;
     }
     else
diff --git a/src/ceres_wrapper/ceres_manager.cpp b/src/ceres_wrapper/ceres_manager.cpp
index 190eff4d0cf782073259f2b76ca82f653a1402c1..dfee1b0c0e8b309e74be9d06bdb588718d154ecc 100644
--- a/src/ceres_wrapper/ceres_manager.cpp
+++ b/src/ceres_wrapper/ceres_manager.cpp
@@ -4,7 +4,8 @@ CeresManager::CeresManager(ceres::Problem::Options _options) :
 	ceres_problem_(new ceres::Problem(_options))
 {
 	ceres::Covariance::Options covariance_options;
-	covariance_options.algorithm_type = ceres::SUITE_SPARSE_QR;//ceres::DENSE_SVD;
+    //covariance_options.algorithm_type = ceres::SUITE_SPARSE_QR;//ceres::DENSE_SVD;
+    covariance_options.num_threads = 8;//ceres::DENSE_SVD;
 	//covariance_options.null_space_rank = -1;
 	covariance_ = new ceres::Covariance(covariance_options);
 }
diff --git a/src/examples/test_ceres_2_lasers.cpp b/src/examples/test_ceres_2_lasers.cpp
index bfaa57f1e42fc4a53bc98eef82a1cdac41cd50a0..8aca178a01e8bdca1c0bc6212d36a707e2681488 100644
--- a/src/examples/test_ceres_2_lasers.cpp
+++ b/src/examples/test_ceres_2_lasers.cpp
@@ -116,7 +116,7 @@ int main(int argc, char** argv)
 
     // Ceres initialization
     ceres::Solver::Options ceres_options;
-    ceres_options.minimizer_type = ceres::LINE_SEARCH;	//ceres::TRUST_REGION;
+    ceres_options.minimizer_type = ceres::TRUST_REGION;	//ceres::TRUST_REGION;LINE_SEARCH
     ceres_options.max_line_search_step_contraction = 1e-3;
     //    ceres_options.minimizer_progress_to_stdout = false;
     //    ceres_options.line_search_direction_type = ceres::LBFGS;