@Override
public List<STPoint> range(STRegion range) {
SQLiteDatabase db = this.getReadableDatabase();
String query = "SELECT id,minX,maxX,minY,maxY,minT,maxT from " + this.table_identifier + " ";
STPoint mins = range.getMins();
STPoint maxs = range.getMaxs();
String prefix = " WHERE ";
if (mins.hasX() && maxs.hasX()) {
query +=
prefix
+ " minX >= "
+ String.valueOf(mins.getX())
+ " AND maxX <= "
+ String.valueOf(maxs.getX());
prefix = " AND ";
}
if (mins.hasY() && maxs.hasY()) {
query +=
prefix
+ " minY >= "
+ String.valueOf(mins.getY())
+ " AND maxY <= "
+ String.valueOf(maxs.getY());
prefix = " AND ";
}
if (mins.hasT() && maxs.hasT()) {
query +=
prefix
+ " minT >= "
+ String.valueOf(mins.getT())
+ " AND maxT <= "
+ String.valueOf(maxs.getT());
prefix = " AND ";
}
Cursor cur = db.rawQuery(query, null);
List<STPoint> points = cursorToList(cur);
db.close();
return points;
}
@Override
public void insert(STPoint point) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put("minX", point.getX());
values.put("maxX", point.getX());
values.put("minY", point.getY());
values.put("maxY", point.getY());
values.put("minT", point.getT());
values.put("maxT", point.getT());
db.insert(
this.table_identifier, // table
null, // nullColumnHack
values); // key/value -> keys = column names/ values = column values
db.close();
}
@Override
public List<STPoint> nearestNeighbor(STPoint needle, STPoint boundValues, int n) {
// TODO support more than one nearest neighbor
if (n != 1) {
throw new RuntimeException("Nearest Neighbor does not support N != 1");
}
List<STPoint> candPoints = new ArrayList<STPoint>();
for (int i = 0; i < 20; i++) {
try {
STRegion miniRegion = GPSLib.getSpaceBoundQuick(needle, boundValues, SPATIAL_TYPE);
candPoints = range(miniRegion);
if (candPoints.size() >= n) {
break;
}
int step = (int) Math.pow(i, 3);
boundValues.setX(step * boundValues.getX());
boundValues.setY(step * boundValues.getY());
boundValues.setT(step * boundValues.getT());
} catch (LSTFilterException e) {
e.printStackTrace();
}
}
STPoint minPoint = null;
double minVal = Double.MAX_VALUE;
for (STPoint point : candPoints) {
// ToDo: optimize this since we use the same needle each time, some values should drop out of
// dist calc.
// ToDO: optimize by using squared values of distance instead of ones using sqrt (expensive)
try {
double distance = GPSLib.distanceBetween(needle, point, SPATIAL_TYPE);
if (distance < minVal) {
minVal = distance;
minPoint = point;
}
} catch (LSTFilterException e) {
e.printStackTrace();
}
}
List<STPoint> minPoints = new ArrayList<STPoint>();
minPoints.add(minPoint);
return minPoints;
}