Title: A polygon chaining algorithm to simplify area encoding
Abstract: Although cumbersome to encode, polygon data structures continue to be a preferred means of storing and manipulating cartographic data in many geographic information systems. The polygon chaining algorithm presented in this paper simplifies polygon encoding by combining many of the strengths of both polygon and topological data structures but few of their attendant weaknesses. The algorithm relies on two sets of data—nts and lines. One polygon reference point is digitized for each polygon to be chained. Lines separating contiguous areas are encoded in any direction and order and may cross other lines. The algorithm inspects these lines for consistency and automatically corrects several common encoding errors. Nodes are then chained around the polygon reference points to form clockwise polygons. After reviewing the advantages and disadvantages of selected data structures, the paper outlines the principal steps in the algorithm and how data is inputted, edited and chained. Discussion then turns to how the algorithm is implemented in a FORTRAN IV program. A sample problem is also presented.
Publication Year: 1984
Publication Date: 1984-01-01
Language: en
Type: article
Indexed In: ['crossref']
Access and Citation
Cited By Count: 1
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot