Next: , Up: Delaunay Triangulation

30.1.1 Plotting the Triangulation

Octave has the functions triplot, trimesh, and trisurf to plot the Delaunay triangulation of a 2-dimensional set of points.

— Function File: triplot (tri, x, y)
— Function File: triplot (tri, x, y, linespec)
— Function File: h = triplot (...)

Plot a triangular mesh in 2D. The variable tri is the triangular meshing of the points (x, y) which is returned from delaunay. If given, linespec determines the properties to use for the lines.

The optional return value h is a graphics handle to the created plot.

See also: plot, trimesh, trisurf, delaunay.

— Function File: trimesh (tri, x, y, z)
— Function File: h = trimesh (...)

Plot a triangular mesh in 3D. The variable tri is the triangular meshing of the points (x, y) which is returned from delaunay. The variable z is value at the point (x, y).

The optional return value h is a graphics handle to the created plot.

See also: triplot, trisurf, delaunay3.

— Function File: trisurf (tri, x, y, z)
— Function File: h = trisurf (...)

Plot a triangular surface in 3D. The variable tri is the triangular meshing of the points (x, y) which is returned from delaunay. The variable z is value at the point (x, y).

The optional return value h is a graphics handle to the created plot.

See also: triplot, trimesh, delaunay3.

The difference between triplot, and trimesh or triplot, is that the former only plots the 2-dimensional triangulation itself, whereas the second two plot the value of a function f (x, y). An example of the use of the triplot function is 

     rand ("state", 2)
     x = rand (20, 1);
     y = rand (20, 1);
     tri = delaunay (x, y);
     triplot (tri, x, y);

which plots the Delaunay triangulation of a set of random points in 2-dimensions. The output of the above can be seen in fig:triplot.

triplot.png

Figure 30.2: Delaunay triangulation of a random set of points