Jacek W
Posts:
2
Registered:
12/4/09


Problem with triangulation using DelaunayTri Class
Posted:
Dec 9, 2009 8:23 AM


I have to triangulate a simple unit triangle (a half of the unit square) with uniform grid. Using DelaunayTri class the triangulation makes a few more triangles on the hypotenuse. This is a straight line the triangle is not supposed to be there. I was able to avoid the problem just for a few specific numbers but not in general. How I can fix it ?? See example: function bary(n) % works nice for n=3,5,9,17; not for any u=linspace(0,1,n); v=linspace(0,1,n); uv=[]; for j=1:n for i=1:nj+1 x=[u(i) v(j)]; uv=[uv; x]; end end % Triangulation of the barycentric coordinates dt=DelaunayTri(uv(:,1),uv(:,2)); T=dt(:,:); Tuv=delaunay(uv(:,1),uv(:,2)); figure(1);clf; scatter(uv(:,1),uv(:,2)) hold on length(T) length(Tuv) triplot(dt,'red') % Labels x=uv(:,1);y=uv(:,2); hold on vxlabels = arrayfun(@(n) {sprintf('P%d', n)}, (1:length(x))'); Hpl = text(x, y+0.03, vxlabels, 'FontWeight', 'bold', 'HorizontalAlignment',... 'center', 'BackgroundColor', 'none'); ic = incenters(dt); numtri = size(dt,1); trilabels = arrayfun(@(x) {sprintf('T%d', x)}, (1:numtri)'); Htl = text(ic(:,1), ic(:,2), trilabels, 'FontWeight', 'bold', ... 'HorizontalAlignment', 'center', 'Color', 'red'); hold off
The delaunay command works fine but I want to use the DlelaunayTri object commands. Should I use delaunay + TriRep to create one ??

