1 files changed, 42 insertions, 24 deletions

diff --git a/src/de/lmu/ifi/dbs/elki/distance/distancefunction/geo/LngLatDistanceFunction.java b/src/de/lmu/ifi/dbs/elki/distance/distancefunction/geo/LngLatDistanceFunction.java
index 98a219dd..e8d2623d 100644
--- a/src/de/lmu/ifi/dbs/elki/distance/distancefunction/geo/LngLatDistanceFunction.java
+++ b/src/de/lmu/ifi/dbs/elki/distance/distancefunction/geo/LngLatDistanceFunction.java
@@ -4,7 +4,7 @@ package de.lmu.ifi.dbs.elki.distance.distancefunction.geo;
  This file is part of ELKI:
  Environment for Developing KDD-Applications Supported by Index-Structures
 
- Copyright (C) 2013
+ Copyright (C) 2014
  Ludwig-Maximilians-Universität München
  Lehr- und Forschungseinheit für Datenbanksysteme
  ELKI Development Team
@@ -26,8 +26,8 @@ package de.lmu.ifi.dbs.elki.distance.distancefunction.geo;
 import de.lmu.ifi.dbs.elki.data.NumberVector;
 import de.lmu.ifi.dbs.elki.data.spatial.SpatialComparable;
 import de.lmu.ifi.dbs.elki.data.type.SimpleTypeInformation;
-import de.lmu.ifi.dbs.elki.data.type.VectorFieldTypeInformation;
-import de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractSpatialDoubleDistanceFunction;
+import de.lmu.ifi.dbs.elki.data.type.TypeUtil;
+import de.lmu.ifi.dbs.elki.distance.distancefunction.AbstractSpatialDistanceFunction;
 import de.lmu.ifi.dbs.elki.math.geodesy.EarthModel;
 import de.lmu.ifi.dbs.elki.math.geodesy.SphericalVincentyEarthModel;
 import de.lmu.ifi.dbs.elki.utilities.documentation.Reference;
@@ -39,9 +39,23 @@ import de.lmu.ifi.dbs.elki.utilities.optionhandling.parameters.ObjectParameter;
 /**
  * Distance function for 2D vectors in Longitude, Latitude form.
  * 
+ * The input data must be in degrees (not radians), and the output distance will
+ * be in meters (see {@link EarthModel#distanceDeg}).
+ * 
+ * This implementation allows index accelerated queries using R*-trees (by
+ * providing a point-to-rectangle minimum distance), as published in:
+ * <p>
+ * Erich Schubert, Arthur Zimek and Hans-Peter Kriegel<br />
+ * Geodetic Distance Queries on R-Trees for Indexing Geographic Data<br />
+ * Advances in Spatial and Temporal Databases - 13th International Symposium,
+ * SSTD 2013, Munich, Germany
+ * </p>
+ * 
  * @author Erich Schubert
+ * 
+ * @apiviz.composedOf EarthModel
  */
-public class LngLatDistanceFunction extends AbstractSpatialDoubleDistanceFunction {
+public class LngLatDistanceFunction extends AbstractSpatialDistanceFunction {
   /**
    * Earth model to use.
    */
@@ -56,33 +70,36 @@ public class LngLatDistanceFunction extends AbstractSpatialDoubleDistanceFunctio
   }
 
   @Override
-  public double doubleDistance(NumberVector<?> o1, NumberVector<?> o2) {
+  public double distance(NumberVector o1, NumberVector o2) {
     return model.distanceDeg(o1.doubleValue(1), o1.doubleValue(0), o2.doubleValue(1), o2.doubleValue(0));
   }
 
   @Override
   @Reference(authors = "Erich Schubert, Arthur Zimek and Hans-Peter Kriegel", title = "Geodetic Distance Queries on R-Trees for Indexing Geographic Data", booktitle = "Advances in Spatial and Temporal Databases - 13th International Symposium, SSTD 2013, Munich, Germany")
-  public double doubleMinDist(SpatialComparable mbr1, SpatialComparable mbr2) {
-    if (mbr1 instanceof NumberVector) {
-      if (mbr2 instanceof NumberVector) {
-        return doubleDistance((NumberVector<?>) mbr1, (NumberVector<?>) mbr2);
-      } else {
-        NumberVector<?> o1 = (NumberVector<?>) mbr1;
+  public double minDist(SpatialComparable mbr1, SpatialComparable mbr2) {
+    if(mbr1 instanceof NumberVector) {
+      if(mbr2 instanceof NumberVector) {
+        return distance((NumberVector) mbr1, (NumberVector) mbr2);
+      }
+      else {
+        NumberVector o1 = (NumberVector) mbr1;
         return model.minDistDeg(o1.doubleValue(1), o1.doubleValue(0), mbr2.getMin(1), mbr2.getMin(0), mbr2.getMax(1), mbr2.getMax(0));
       }
-    } else {
-      if (mbr2 instanceof NumberVector) {
-        NumberVector<?> o2 = (NumberVector<?>) mbr2;
+    }
+    else {
+      if(mbr2 instanceof NumberVector) {
+        NumberVector o2 = (NumberVector) mbr2;
         return model.minDistDeg(o2.doubleValue(1), o2.doubleValue(0), mbr1.getMin(1), mbr1.getMin(0), mbr1.getMax(1), mbr1.getMax(0));
-      } else {
+      }
+      else {
         throw new NotImplementedException("This distance function cannot - yet - be used with this algorithm, as the lower bound rectangle to rectangle distances have not yet been formalized for geodetic data.");
       }
     }
   }
 
   @Override
-  public SimpleTypeInformation<? super NumberVector<?>> getInputTypeRestriction() {
-    return new VectorFieldTypeInformation<>(NumberVector.class, 2);
+  public SimpleTypeInformation<? super NumberVector> getInputTypeRestriction() {
+    return TypeUtil.NUMBER_VECTOR_FIELD_2D;
   }
 
   @Override
@@ -95,21 +112,22 @@ public class LngLatDistanceFunction extends AbstractSpatialDoubleDistanceFunctio
 
   @Override
   public boolean equals(Object obj) {
-    if (this == obj) {
+    if(this == obj) {
       return true;
     }
-    if (obj == null) {
+    if(obj == null) {
       return false;
     }
-    if (getClass() != obj.getClass()) {
+    if(getClass() != obj.getClass()) {
       return false;
     }
     LngLatDistanceFunction other = (LngLatDistanceFunction) obj;
-    if (model == null) {
-      if (other.model != null) {
+    if(model == null) {
+      if(other.model != null) {
         return false;
       }
-    } else if (!model.equals(other.model)) {
+    }
+    else if(!model.equals(other.model)) {
       return false;
     }
     return true;
@@ -137,7 +155,7 @@ public class LngLatDistanceFunction extends AbstractSpatialDoubleDistanceFunctio
     protected void makeOptions(Parameterization config) {
       super.makeOptions(config);
       ObjectParameter<EarthModel> modelP = new ObjectParameter<>(EarthModel.MODEL_ID, EarthModel.class, SphericalVincentyEarthModel.class);
-      if (config.grab(modelP)) {
+      if(config.grab(modelP)) {
         model = modelP.instantiateClass(config);
       }
     }