Algorithms for the Production of Contour Maps over an Irregular Triangular Mesh

摘要

For the solution of partial differential equations by finite element methods, the region over which the solution is required is often divided up into an irregular triangular mesh. Algorithms are given for the production of contour maps of functions defined at the vertices of such meshes. The ALGOL implementations are appended. In the first algorithm each triangular element is dealt with in turn and contours of all the required heights drawn as straight lines within the element. In the other two algorithms (which are related), each contour is followed through the mesh from element to element, thereby allowing the contours to be drawn as smooth curves if required. (Author)