Isotopic Invariant for Planar Drawings of Connected Planar Graphs

摘要

In the report, the authors will present a data structure called PLA-structure forrepresenting the topological information of a database containing points, lines, and areas in a plane. This data structure gives for every point in the database the circular alternating list of incident lines and adjacent areas that one sees as one proceeds clockwise around the point. It will be shown in the report that if the authors add an indication of which area is the 'outside' of the drawing in the plane, the data-structure is a complete isotopic invariant.