From 2ce74c05e16cd178a38c08080568b47b9ae4f08c Mon Sep 17 00:00:00 2001
From: Patrick Niklaus <patrick.niklaus@student.kit.edu>
Date: Thu, 7 Jan 2016 16:30:54 +0100
Subject: [PATCH] Use a sane gps_precision multipler

---
 plugins/match.hpp | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/plugins/match.hpp b/plugins/match.hpp
index f1769562f..e213d19ab 100644
--- a/plugins/match.hpp
+++ b/plugins/match.hpp
@@ -51,8 +51,6 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 template <class DataFacadeT> class MapMatchingPlugin : public BasePlugin
 {
-    constexpr static const unsigned max_number_of_candidates = 10;
-
     std::shared_ptr<SearchEngine<DataFacadeT>> search_engine_ptr;
 
     using ClassifierT = BayesClassifier<LaplaceDistribution, LaplaceDistribution, double>;
@@ -101,7 +99,9 @@ template <class DataFacadeT> class MapMatchingPlugin : public BasePlugin
     {
         osrm::matching::CandidateLists candidates_lists;
 
-        double query_radius = 10 * gps_precision;
+        // assuming the gps_precision is the standart-diviation of normal distribution that models
+        // GPS noise (in this model) this should give us the correct candidate with >0.95
+        double query_radius = 3 * gps_precision;
         double last_distance =
             coordinate_calculation::haversine_distance(input_coords[0], input_coords[1]);