Coord_Space

A coord space uses coordinates in a coordinate system to implement its metric. It can answer metric queries with Geoms (as with all metric spaces) or with Coords.

Most implementations allow a coordinate system to be provided to the constructor; by default, they create a Euclidean one of the proper dimension.

• Coord_Space_2D_Array: Stores geoms objects in an array based on the (integer part of) its coordinates.
  Constructor args: int xdim, int ydim. Only 2-D Euclidean coordinate systems are supported. Query coordinates must be non-negative integers less than the dimensions.
• Coord_Space_2D_Buckets: Extends the 2-d array to allow negative and non-integer coordinates; the space is discretized, and multiple objects in each slot of the array.
  Constructor args: int xmin, int ymin, int xmax, int ymax, int xdens, int ydens. The densities specify how many grid partitions per unit, an integer >= 1.
  ALternate constructor args: base metric space. The bounding box, density, etc. are automatically estimated.
• Coord_Space_Centroid: Measures distances between objects by the distances between their centroids.
• Coord_Space_Coords: User-specified function yields representative coords for measuring distances.
  Constructor args: coords function.
• Coord_Space_KD_Tree: Stores geoms in a tree where each level branches on coordinates in one dimension.
  Constructor args: k.

• coord_system: Coord_Space -> int
  Returns the coordinate system of the space.
• distance: Coord_Space . Coords . Geom -> double
  Returns the distance between the coords and geom.
• distance: Coord_Space . Coords . Coords -> double
  Returns the distance between the two coords.
• near: Coord_Space . Coords . double radius . Geoms -> void
  Like metric space near, but query is with coords.
• nearest: Coord_Space . Geom . double radius=-1 -> Geom
  Like metric space nearest, but query is with coords.