The Research Of Contour Line Generating Algorithm

Geographical map is a kind of map symbol for showing natural or human phenomena, a kind of tool for people cognizing the world. With the development of surveying, digit-storage instead of paper-storage, computer controlling, managing, showing and digital map outputting to paper mediator when they will be required are the important parts of kinds of automating system.In the course of digital map editing, we always run into problem of contour line shorting, thus, we should interpolate new contour lines from original ones. Usually draftsman can draw new contour lines by mouse according to one's experience. In order to cater the 3-D showing of contour line, we should generate different contour interval lines and compatible with each others. If we draw them one by one, the large amount of work we should dois hard to imagine. Without any doubt, it is a bright point in geographical map editing that we start to think drawing them by automatically, effectively and precisely. So the writer bases her tutor's software-EasyMapRead, analyzes a wild variety of Delaunay triangulation algorithm that are used in the creation of DTM based on the triangulate irregular network (TIN), creates triangulation net from discrete points and fits contour lines. Take into account suiting to map editing and 3-D display, the subject realizes direct drawing of contour line from discrete points, tries deleting and interpolating of contour line.Contour lines interpolating is interpolate new contour lines accord to original ones and agreement to them, it is very useful for contour lines interpolating voluntarily.