From 523ff6a4a6f0040c2623a414ac9f61293615bf10 Mon Sep 17 00:00:00 2001
From: Selim Eser <2211482@stud.hs-mannheim.de>
Date: Sun, 9 Jun 2024 17:54:58 +0200
Subject: [PATCH] Changed destination formula to Haversine and multiplied
 return distance by 1.25 for distance using the streets

---
 src/main/java/de/hs_mannheim/domain/System.java | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/main/java/de/hs_mannheim/domain/System.java b/src/main/java/de/hs_mannheim/domain/System.java
index 5d8c180..897cf8e 100644
--- a/src/main/java/de/hs_mannheim/domain/System.java
+++ b/src/main/java/de/hs_mannheim/domain/System.java
@@ -233,7 +233,14 @@ public class System {
             }
         } catch (Exception e) {}
 
-        return "" + (Math.acos(Math.sin(lat1) * Math.sin(lat2) + Math.cos(lat1) * Math.cos(lat2) * Math.cos(lon2 - lon1)) * 111.324) + " km";
+        double dLat = lat2-lat1;
+        double dLon = lon2-lon1;
+
+        double a = Math.pow(Math.sin(Math.toRadians(dLat/2.0)), 2) + Math.pow(Math.sin(Math.toRadians(dLon/2.0)), 2) * Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2));
+
+        double distance = 6378.388 * 2.0 * Math.atan2(Math.sqrt(a), Math.sqrt(1.0-a));
+
+        return "" + (distance * 1.25) + " km";
     
     }