Update LocationHelper

- Add method for weighted average - Set Timestamp on location creation
microg · Apr 3, 2016 · 19d9ede · 19d9ede
1 parent 2cfb3dd
commit 19d9ede
Showing 1 changed file with 54 additions and 27 deletions.
diff --git a/unifiednlp-api/src/main/java/org/microg/nlp/api/LocationHelper.java b/unifiednlp-api/src/main/java/org/microg/nlp/api/LocationHelper.java
@@ -22,38 +22,41 @@
 import java.util.Collection;
 
 public final class LocationHelper {
+ public static final String EXTRA_AVERAGED_OF = "AVERAGED_OF";
+ public static final String EXTRA_TOTAL_WEIGHT = "org.microg.nlp.TOTAL_WEIGHT";
+ public static final String EXTRA_TOTAL_ALTITUDE_WEIGHT = "org.microg.nlp.TOTAL_ALTITUDE_WEIGHT";
+ public static final String EXTRA_WEIGHT = "org.microg.nlp.WEIGHT";
+
  private LocationHelper() {
  }
 
  public static Location create(String source) {
- return new Location(source);
+ Location l = new Location(source);
+ l.setTime(System.currentTimeMillis());
+ return l;
  }
 
- public static Location create(String source, double latitude, double longitude,
- float accuracy) {
+ public static Location create(String source, double latitude, double longitude, float accuracy) {
  Location location = create(source);
  location.setLatitude(latitude);
  location.setLongitude(longitude);
  location.setAccuracy(accuracy);
  return location;
  }
 
- public static Location create(String source, double latitude, double longitude, float altitude,
- Bundle extras) {
+ public static Location create(String source, double latitude, double longitude, float altitude, Bundle extras) {
  Location location = create(source, latitude, longitude, altitude);
  location.setExtras(extras);
  return location;
  }
 
- public static Location create(String source, double latitude, double longitude, double altitude,
- float accuracy) {
+ public static Location create(String source, double latitude, double longitude, double altitude, float accuracy) {
  Location location = create(source, latitude, longitude, accuracy);
  location.setAltitude(altitude);
  return location;
  }
 
- public static Location create(String source, double latitude, double longitude, double altitude,
- float accuracy, Bundle extras) {
+ public static Location create(String source, double latitude, double longitude, double altitude, float accuracy, Bundle extras) {
  Location location = create(source, latitude, longitude, altitude, accuracy);
  location.setExtras(extras);
  return location;
@@ -72,33 +75,57 @@ public static Location create(String source, long time, Bundle extras) {
  }
 
  public static Location average(String source, Collection<Location> locations) {
- if (locations == null || locations.size() == 0) {
+ return weightedAverage(source, locations, LocationBalance.BALANCED, new Bundle());
+ }
+
+ public static Location weightedAverage(String source, Collection<Location> locations, LocationBalance balance, Bundle extras) {
+ if (locations == null || locations.isEmpty()) {
  return null;
  }
- int num = locations.size();
- double latitude = 0;
- double longitude = 0;
- float accuracy = 0;
- int altitudes = 0;
- double altitude = 0;
+ double total = 0;
+ double lat = 0;
+ double lon = 0;
+ float acc = 0;
+ double altTotal = 0;
+ double alt = 0;
  for (Location value : locations) {
  if (value != null) {
- latitude += value.getLatitude();
- longitude += value.getLongitude();
- accuracy += value.getAccuracy();
+ double weight = balance.getWeight(value);
+ total += weight;
+ lat += value.getLatitude() * weight;
+ lon += value.getLongitude() * weight;
+ acc += value.getAccuracy() * weight;
  if (value.hasAltitude()) {
- altitude += value.getAltitude();
- altitudes++;
+ alt += value.getAltitude();
+ altTotal += weight;
  }
  }
  }
- Bundle extras = new Bundle();
- extras.putInt("AVERAGED_OF", num);
- if (altitudes > 0) {
- return create(source, latitude / num, longitude / num, altitude / altitudes,
- accuracy / num, extras);
+ if (extras == null) extras = new Bundle();
+ extras.putInt(EXTRA_AVERAGED_OF, locations.size());
+ extras.putDouble(EXTRA_TOTAL_WEIGHT, total);
+ if (altTotal > 0) {
+ extras.putDouble(EXTRA_TOTAL_ALTITUDE_WEIGHT, altTotal);
+ return create(source, lat / total, lon / total, alt / altTotal, (float) (acc / total), extras);
  } else {
- return create(source, latitude / num, longitude / num, accuracy / num, extras);
+ return create(source, lat / total, lon / total, (float) (acc / total), extras);
  }
  }
+
+ public interface LocationBalance {
+ LocationBalance BALANCED = new LocationBalance() {
+ @Override
+ public double getWeight(Location location) {
+ return 1;
+ }
+ };
+ LocationBalance FROM_EXTRA = new LocationBalance() {
+ @Override
+ public double getWeight(Location location) {
+ return location.getExtras() == null ? 1 : location.getExtras().getDouble(EXTRA_WEIGHT, 1);
+ }
+ };
+
+ double getWeight(Location location);
+ }
 }