Moving to more realistic routing example

Author: merschformann

java-ortools-routing/input.json

@@ -1,74 +1,115 @@
 {
-  "distance_matrix": [
-    [
-      0, 548, 776, 696, 582, 274, 502, 194, 308, 194, 536, 502, 388, 354, 468,
-      776, 662
-    ],
-    [
-      548, 0, 684, 308, 194, 502, 730, 354, 696, 742, 1084, 594, 480, 674, 1016,
-      868, 1210
-    ],
-    [
-      776, 684, 0, 992, 878, 502, 274, 810, 468, 742, 400, 1278, 1164, 1130,
-      788, 1552, 754
-    ],
-    [
-      696, 308, 992, 0, 114, 650, 878, 502, 844, 890, 1232, 514, 628, 822, 1164,
-      560, 1358
-    ],
-    [
-      582, 194, 878, 114, 0, 536, 764, 388, 730, 776, 1118, 400, 514, 708, 1050,
-      674, 1244
-    ],
-    [
-      274, 502, 502, 650, 536, 0, 228, 308, 194, 240, 582, 776, 662, 628, 514,
-      1050, 708
-    ],
-    [
-      502, 730, 274, 878, 764, 228, 0, 536, 194, 468, 354, 1004, 890, 856, 514,
-      1278, 480
-    ],
-    [
-      194, 354, 810, 502, 388, 308, 536, 0, 342, 388, 730, 468, 354, 320, 662,
-      742, 856
-    ],
-    [
-      308, 696, 468, 844, 730, 194, 194, 342, 0, 274, 388, 810, 696, 662, 320,
-      1084, 514
-    ],
-    [
-      194, 742, 742, 890, 776, 240, 468, 388, 274, 0, 342, 536, 422, 388, 274,
-      810, 468
-    ],
-    [
-      536, 1084, 400, 1232, 1118, 582, 354, 730, 388, 342, 0, 878, 764, 730,
-      388, 1152, 354
-    ],
-    [
-      502, 594, 1278, 514, 400, 776, 1004, 468, 810, 536, 878, 0, 114, 308, 650,
-      274, 844
-    ],
-    [
-      388, 480, 1164, 628, 514, 662, 890, 354, 696, 422, 764, 114, 0, 194, 536,
-      388, 730
-    ],
-    [
-      354, 674, 1130, 822, 708, 628, 856, 320, 662, 388, 730, 308, 194, 0, 342,
-      422, 536
-    ],
-    [
-      468, 1016, 788, 1164, 1050, 514, 514, 662, 320, 274, 388, 650, 536, 342,
-      0, 764, 194
-    ],
-    [
-      776, 868, 1552, 560, 674, 1050, 1278, 742, 1084, 810, 1152, 274, 388, 422,
-      764, 0, 798
-    ],
-    [
-      662, 1210, 754, 1358, 1244, 708, 480, 856, 514, 468, 354, 844, 730, 536,
-      194, 798, 0
-    ]
+  "defaults": {
+    "vehicles": {
+      "start_location": {
+        "lon": 7.625,
+        "lat": 51.9622
+      },
+      "end_location": {
+        "lon": 7.625,
+        "lat": 51.9622
+      },
+      "start_time": "2024-03-19T11:00:00+00:00",
+      "capacity": 5
+    },
+    "stops": {
+      "quantity": 1
+    }
+  },
+  "vehicles": [
+    {
+      "id": "vehicle-1"
+    },
+    {
+      "id": "vehicle-2"
+    }
   ],
-  "num_vehicles": 4,
-  "depot": 0
+  "stops": [
+    {
+      "id": "location-1",
+      "location": {
+        "lon": 7.6228,
+        "lat": 51.9624
+      }
+    },
+    {
+      "id": "location-2",
+      "location": {
+        "lon": 7.6353,
+        "lat": 51.9584
+      }
+    },
+    {
+      "id": "location-3",
+      "location": {
+        "lon": 7.6233,
+        "lat": 51.9638
+      }
+    },
+    {
+      "id": "location-4",
+      "location": {
+        "lon": 7.6163,
+        "lat": 51.9635
+      }
+    },
+    {
+      "id": "location-5",
+      "location": {
+        "lon": 7.6045,
+        "lat": 51.9509
+      }
+    },
+    {
+      "id": "location-6",
+      "location": {
+        "lon": 7.6292,
+        "lat": 51.9577
+      }
+    },
+    {
+      "id": "location-7",
+      "location": {
+        "lon": 7.6385,
+        "lat": 51.9694
+      }
+    },
+    {
+      "id": "location-8",
+      "location": {
+        "lon": 7.6628,
+        "lat": 51.9616
+      }
+    },
+    {
+      "id": "location-9",
+      "location": {
+        "lon": 7.6217,
+        "lat": 51.9667
+      }
+    },
+    {
+      "id": "location-10",
+      "location": {
+        "lon": 7.6299,
+        "lat": 51.9582
+      }
+    }
+  ],
+  "duration_matrix": [
+    [0, 831, 968, 648, 773, 689, 872, 997, 685, 698, 613, 613, 613, 613],
+    [822, 0, 415, 257, 273, 83, 152, 266, 212, 74, 262, 262, 262, 262],
+    [925, 466, 0, 342, 499, 454, 447, 624, 294, 463, 372, 372, 372, 372],
+    [647, 293, 456, 0, 207, 168, 275, 452, 88, 178, 101, 101, 101, 101],
+    [775, 385, 584, 202, 0, 280, 387, 544, 238, 289, 229, 229, 229, 229],
+    [739, 143, 455, 211, 228, 0, 191, 308, 249, 9, 179, 179, 179, 179],
+    [843, 152, 415, 260, 348, 158, 0, 274, 201, 149, 297, 297, 297, 297],
+    [1001, 270, 573, 418, 466, 276, 293, 0, 370, 267, 455, 455, 455, 455],
+    [687, 217, 444, 89, 247, 208, 199, 375, 0, 214, 141, 141, 141, 141],
+    [748, 134, 446, 203, 219, 9, 182, 299, 240, 0, 188, 188, 188, 188],
+    [613, 272, 372, 102, 221, 129, 320, 437, 139, 138, 0, 0, 0, 0],
+    [613, 272, 372, 102, 221, 129, 320, 437, 139, 138, 0, 0, 0, 0],
+    [613, 272, 372, 102, 221, 129, 320, 437, 139, 138, 0, 0, 0, 0],
+    [613, 272, 372, 102, 221, 129, 320, 437, 139, 138, 0, 0, 0, 0]
+  ]
 }

java-ortools-routing/java-ortools.code-workspace

@@ -18,5 +18,6 @@
   },
   "extensions": {
     "recommendations": ["ms-vscode-remote.remote-containers"]
-  }
+  },
+  "settings": {}
 }

java-ortools-routing/src/main/java/com/nextmv/example/Input.java

@@ -2,49 +2,69 @@
 
 import java.io.BufferedReader;
 import java.io.InputStreamReader;
+import java.util.List;
 import java.util.stream.Collectors;
 
 import com.google.gson.Gson;
 import com.google.gson.annotations.SerializedName;
 
 public class Input {
-  @SerializedName(value = "distance_matrix")
-  public final long[][] distanceMatrix;
-  @SerializedName(value = "num_vehicles")
-  public final int vehicleNumber;
-  public final int depot;
+  public final class Location {
+    public double lat;
+    public double lon;
 
-  public Input(int vehicleNumber, int depot, long[][] distanceMatrix) {
-    this.distanceMatrix = new long[vehicleNumber+1][vehicleNumber+1];
-    this.vehicleNumber = vehicleNumber;
-    this.depot = depot;
-    for (int i = 0; i < vehicleNumber+1; i++) {
-      for (int j = 0; j < vehicleNumber+1; j++) {
-        this.distanceMatrix[i][j] = distanceMatrix[i][j];
-      }
+    public Location(double lat, double lon) {
+      this.lat = lat;
+      this.lon = lon;
     }
   }
 
-  public long[][] getDistanceMatrix() {
-    return this.distanceMatrix;
+  public final class Vehicle {
+    public String id;
+
+    public Vehicle(String id) {
+      this.id = id;
+    }
   }
 
-  public int getVehicleNumber() {
-    return this.vehicleNumber;
+  public final class Stop {
+    public String id;
+    public Location location;
   }
 
-  public int getDepot() {
-    return this.depot;
+  @SerializedName(value = "duration_matrix")
+  public final long[][] durationMatrix;
+  public final List<Vehicle> vehicles;
+  public final List<Stop> stops;
+
+  public Input(
+      long[][] durationMatrix,
+      List<Vehicle> vehicles,
+      List<Stop> stops) {
+    if (durationMatrix != null) {
+      for (long[] row : durationMatrix) {
+        if (row.length != durationMatrix.length) {
+          throw new IllegalArgumentException("Duration matrix must be square.");
+        }
+      }
+      if (durationMatrix.length != stops.size() * 2 * vehicles.size()) {
+        throw new IllegalArgumentException(
+            "Duration matrix size does not match number of stops and vehicles (n_stops + 2 * n_vehicles).");
+      }
+    }
+
+    this.durationMatrix = durationMatrix;
+    this.vehicles = vehicles;
+    this.stops = stops;
   }
-  
+
   public static Input fromString(String path) {
     Gson gson = new Gson();
     // Read stdin if no path is provided.
     if (path.isEmpty()) {
       try (BufferedReader reader = new BufferedReader(new InputStreamReader(System.in))) {
         return gson.fromJson(
-          reader.lines().collect(Collectors.joining("\n")), Input.class
-        );
+            reader.lines().collect(Collectors.joining("\n")), Input.class);
       } catch (java.io.IOException e) {
         System.err.println("Error reading stdin: " + e.getMessage());
         System.exit(1);
@@ -54,9 +74,8 @@ public static Input fromString(String path) {
     // Read the path otherwise.
     try {
       return gson.fromJson(
-        java.nio.file.Files.readString(java.nio.file.Paths.get(path)),
-        Input.class
-      );
+          java.nio.file.Files.readString(java.nio.file.Paths.get(path)),
+          Input.class);
     } catch (java.io.IOException e) {
       System.err.println("Error reading '" + path + "': " + e.getMessage());
       System.exit(1);

java-ortools-routing/src/main/java/com/nextmv/example/Main.java

@@ -25,20 +25,45 @@ public static void main(String[] args) {
 
     Loader.loadNativeLibraries();
 
+    // Generate all vehicle start / end indices.
+    int[] startIndices = new int[input.vehicles.size()];
+    int[] endIndices = new int[input.vehicles.size()];
+    for (int i = 0; i < input.vehicles.size(); ++i) {
+      startIndices[i] = input.stops.size() + i * 2;
+      endIndices[i] = input.stops.size() + i * 2 + 1;
+    }
+
     // Create Routing Index Manager.
-    RoutingIndexManager manager = new RoutingIndexManager(input.distanceMatrix.length, input.vehicleNumber,
-        input.depot);
+    RoutingIndexManager manager = new RoutingIndexManager(
+        input.stops.size() + 2 * input.vehicles.size(),
+        input.vehicles.size(),
+        startIndices,
+        endIndices);
 
     // Create Routing Model.
     RoutingModel routing = new RoutingModel(manager);
 
     // Create and register a transit callback.
-    final int transitCallbackIndex = routing.registerTransitCallback((long fromIndex, long toIndex) -> {
-      // Convert from routing variable Index to user NodeIndex.
-      int fromNode = manager.indexToNode(fromIndex);
-      int toNode = manager.indexToNode(toIndex);
-      return input.distanceMatrix[fromNode][toNode];
-    });
+    int transitCallbackIndex;
+    if (input.durationMatrix != null) {
+      // If durationMatrix is provided, use it.
+      transitCallbackIndex = routing.registerTransitCallback((long fromIndex, long toIndex) -> {
+        int fromNode = manager.indexToNode(fromIndex);
+        int toNode = manager.indexToNode(toIndex);
+        return input.durationMatrix[fromNode][toNode];
+      });
+    } else {
+      // If durationMatrix is not provided, use haversine distance.
+      transitCallbackIndex = routing.registerTransitCallback((long fromIndex, long toIndex) -> {
+        int fromNode = manager.indexToNode(fromIndex);
+        int toNode = manager.indexToNode(toIndex);
+        return (long) haversine(
+            input.stops.get(fromNode).location.lat,
+            input.stops.get(fromNode).location.lon,
+            input.stops.get(toNode).location.lat,
+            input.stops.get(toNode).location.lon);
+      });
+    }
 
     // Define cost of each arc.
     routing.setArcCostEvaluatorOfAllVehicles(transitCallbackIndex);
@@ -72,7 +97,7 @@ static Output getOutput(
       Assignment solution, long solveStartTime) {
     long maxRouteDistance = 0;
     List<Vehicle> vehicles = new ArrayList<Vehicle>();
-    for (int i = 0; i < input.vehicleNumber; ++i) {
+    for (int i = 0; i < input.vehicles.size(); ++i) {
       List<Integer> stops = new ArrayList<Integer>();
       long index = routing.start(i);
       long routeDistance = 0;
@@ -106,4 +131,25 @@ static Output getOutput(
         duration,
         runDuration);
   }
+
+  /**
+   * Haversine formula to calculate the distance between two points on the Earth
+   * given their latitude and longitude.
+   * 
+   * @param lat1 latitude of the first point
+   * @param lon1 longitude of the first point
+   * @param lat2 latitude of the second point
+   * @param lon2 longitude of the second point
+   * @return the distance in kilometers between the two points
+   */
+  private static double haversine(double lat1, double lon1, double lat2, double lon2) {
+    final double R = 6371; // Radius of the Earth in kilometers
+    double latDistance = Math.toRadians(lat2 - lat1);
+    double lonDistance = Math.toRadians(lon2 - lon1);
+    double a = Math.sin(latDistance / 2) * Math.sin(latDistance / 2) +
+        Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2)) *
+            Math.sin(lonDistance / 2) * Math.sin(lonDistance / 2);
+    double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
+    return R * c;
+  }
 }