MakeRecipDistanceValueSource() public method

Returns a ValueSource with values ranging from 1 to 0, depending inversely on the distance from MakeDistanceValueSource(IPoint). The formula is c / (d + c) where 'd' is the distance and 'c' is one tenth the distance to the farthest edge from the center. Thus the scores will be 1 for indexed points at the center of the query shape and as low as ~0.1 at its furthest edges.
public MakeRecipDistanceValueSource ( IShape queryShape ) : ValueSource
queryShape IShape
return ValueSource
SpatialStrategy Class Documentation
Example #1
0
		public Query MakeQuery(Query existingQuery, SpatialStrategy spatialStrategy, string shapeWKT, SpatialRelation relation,
									  double distanceErrorPct = 0.025, SpatialUnits? unitOverride = null)
		{
			SpatialOperation spatialOperation;
			var shape = ReadShape(shapeWKT, unitOverride);

			switch (relation)
			{
				case SpatialRelation.Within:
					spatialOperation = SpatialOperation.IsWithin;
					break;
				case SpatialRelation.Contains:
					spatialOperation = SpatialOperation.Contains;
					break;
				case SpatialRelation.Disjoint:
					spatialOperation = SpatialOperation.IsDisjointTo;
					break;
				case SpatialRelation.Intersects:
					spatialOperation = SpatialOperation.Intersects;
					break;
				case SpatialRelation.Nearby:
					// only sort by this, do not filter
					return new FunctionQuery(spatialStrategy.MakeDistanceValueSource(shape.GetCenter()));
				default:
					throw new ArgumentOutOfRangeException("relation");
			}
			var args = new SpatialArgs(spatialOperation, shape) { DistErrPct = distanceErrorPct };

			if (existingQuery is MatchAllDocsQuery)
				return new CustomScoreQuery(spatialStrategy.MakeQuery(args), new ValueSourceQuery(spatialStrategy.MakeRecipDistanceValueSource(shape)));
			return spatialStrategy.MakeQuery(args);
		}