Topological data model

Introduction

The boundary model is an improved representation that deals with the disadvantages of the naive polygon which is described in polygons. It stores parts of a polygon’s boundary as non-looping arcs and indicates which polygon is on the left and which is on the right of each arc. A simple example of the boundary model can be seen below. It illustrates which additional information is stored about spatial relationships between lines and polygons. Obviously, real coordinates for nodes (and vertices) will also be stored in another table. The boundary model is also called the topological data model as it captures some topological information, such as polygon neighbourhood, for example. You can read more about topological information in Topology. Observe that it is a matter of a simple query to find all the polygons that are the neighbour of a given polygon, unlike the case above.

Explanation

Figure: A simple boundary model for the polygons A, B and C. For each arc, we store the start and end node (as well as a vertex list, but his has been omitted from the table), its left and right polygon. The "polygon" W denotes the polygon of the outside world.

 

Synonyms

Boundary model

Learning outcomes

Prior knowledge

Outgoing relations

Incoming relations

  • Topology is used by Topological data model

Learning paths