Study Arithmetic Of Triangulated Irregular Network With Application

GIS(Geographic Information Systems) is a computer system with collecting , checking , intergreting and analysing information which is related with interface of earth . Digital Terrain Model display two demission geographic position and relational properts information with digital pattern. DTM is an important component of Gis,and is basic of "digital earth".This paper is about of arithmetic studys of triangulated irregular network which is published in abroad and home, and alter an arithmetic of Delaunay Triangulation Using a Uniform Grid which was present by Tsung-Pao Fang and Les A.Piegl of University of South Florida . In this paper I present implementation details,test,examples of the arithmetic, moreover.a triangulated irregular network model of is built for geochemistry. This model can dispose data of geochemistry.Based on analyzing arithmetic of triangulated network, especially deeply studying Delaunay arithmetic,I select a Delaunay arithmetic which was present by Tsung-pao fang and Les.piegl as the kernel of model.The triangulation process consists of three majorsteps:fmding start point and the first edge .forming triangles.and putting triangles together. In forming triangles, I present a new clockwise judge pattern to the arithmetic . In outputing triangles,I set up a topo structure of triangles and output them .these changes can improve efficency of arithmetic .I tested the algorithm with data points and found the time complexity to be linear.According to geochemistry data and geochemistry work, I build a geochemistry digital model of triangulated irregular network ,which can auto trace multi-work area and multi-hole by judging limited length.On the basis of the geochemistry digital model arithmetic of triangulated irregular network , I change the arithmetic of auto-tracing isoline . In process of auto-tracing isoline, the proplem of tracing-crossand and mini-heave was resolved .The isoline is smoothec by linear overlap algorithm . In addtion , the model can build other unit of map such as extramum point, polygon .The software was designed with the OOA method . the software was analysed by UML with rational rose . then realized by c plus plus languge in windows os environment.