Here is a simple example, adapted from the documentation from DelaunayTri:
x = rand(4,1);
y = rand(4,1);
dt = DelaunayTri(x,y)
triplot(dt)
dt.X is a 4x2 array, listing the (x,y) coordinates of the four input points. Consider these to be points 1,2,3,4 in the order listed by dt.X, NOT the order of the input.
The triangulation will create three triangles. Each row of the output variable dt.triangulation tells you information about ONE of those triangles. So, for example, if one row of dt.triangulation is
then that is saying that the 2nd, 4th, and 3rd points from dt.X form one of the Delaunay triangles.
Note that
lists many more methods for the DelaunayTri class.
I hope that helps.
Best Answer
http://www.mathopenref.com/coordtrianglearea.html