IdCoordinateSource

An id coordinate source provides a mapping between ids of a coordinate and the actual coordinates latitude and longitude values. The id coordinate source itself is an interface that provides some methods to get coordinates, ids of coordinates or the distance between a given coordinate and other coordinates.

Information

Attribute	Remarks
Id	An integer value for identifying the coordinate.
Coordiante	Geographical information presented as Lat/long of a Point.

Known implementations:

The following implementations are currently known:

• Csv Id Coordinate Source

• Sql Id Coordinate Source

Method for coordinates:

The IdCoordinateSource contains method for returning coordinates for given ids.

    Optional<Point> getCoordinate(int id)
    Collection<Point> getCoordinates(int... ids)
    Collection<Point> getAllCoordinates()

1. This method is used to return the coordinate of a given id. If no coordinate is found for the given id, an empty optional is returned.

2. This method is used to return the coordinates of a given set of ids. The method will only return coordinates for existing ids.

3. This method is used to return all available coordinates.

Method for ids:

The IdCoordinateSource contains a method for retrieving the id of a given coordinate.

    Optional<Integer> getId(Point coordinate)

This method is used to return the id of a given coordinate. If no id is found for the given coordinate, an empty optional is returned.

Method for retrieving near coordinates:

The IdCoordinateSource also contains methods for retrieving coordinates/points that are near a given coordinate. All implementations of these methods in this project will use the method restrictToBoundingBox for finding and returning four corner points.

    List<CoordinateDistance> getNearestCoordinates(Point coordinatem int n)
    List<CoordinateDistance> getClosestCoordinates(Point coordinate, int n, ComparableQuantity<Length> distance)
    List<CoordinateDistance> calculateCoordinateDistances(Point coordinate, int n, Collection<Point> coordinates)

1. This method will return the nearest n coordinates for a given coordinate. The method works by having a default radius that is increased with every iteration until n coordinates are found.

2. This method will return the closest n coordinates for a given coordinate. Unlike the first method, this method has a defined radius, that won’t be increased. Therefor this method can only consider the coordinates inside the bounding box around this radius.

3. This method is used to calculate the distances to a set of give coordinates. After the calculation the method will return the closest n coordinates. If the number of distances is less than n, this method will return less than n coordinates.

Finding and returning the closest corner coordinates:

In most cases we need four corner coordinates for our given coordinate. Therefor the IdCoordinateSource contains a method that will use the calculated distances to find the closest corner coordinates for the given coordinate.

    List<CoordinateDistance> restrictToBoundingBox(
          Point coordinate,
          Collection<CoordinateDistance> distances,
          int numberOfPoints
    )

For a given set of coordinates, the closest four corner coordinates plus more close points if n > 4 are returned. If n < 4 the method will return the closest n corner coordinates. If the set of coordinates contains a coordinate that matches the given coordinate, only this one coordinate is returned. If n > number of coordinates in the set, all coordinates are returned.