A very simply set set of points to test the tripack functions, taken
from the FORTRAN original. tritest2 is a slight modification by
adding runif(,-0.1,0.1) random numbers to the coordinates.
Arguments
References
R. J. Renka (1996). Algorithm 751: TRIPACK: a constrained
two-dimensional Delaunay triangulation package.
ACM Transactions on Mathematical Software.
22, 1-8.