Steps in triangulation:
Delaunay Triangulation: first pass find optimum triangles
Thiessen, Voronoi, or Dirichlet polygons
Many applications: town locations in middle of regions (peasants go to nearest town for market), crystal cooling
Honors every data point--no data point will be on the wrong side of the contour lines.
Strictly speaking triangulation does not extrapolate beyond data points and has an irregular edge at data points, but the edges may be "beautified" by extrapolation.
Can smooth the curves later for more pleasing look to avoid the straight line segments.
Last revision 10/23/2012