Vein model based on iterated function system

Iterated Function System (IFS) is a mathematical methods of fractal set, and it is an effective way to study self-similar structure. The basic idea: set a target set G of R² (as a graphic), if I could find a set of affine transformation W1, W2,..., Wn, so that they transform graphics coverage, then the attractor of the IFS, constituted by the group of affine transformation of G is a good approximation. The veins form of self-similar structure with similar or statistical significance of the observation and measurement. We analysis its specific structure, summarize the characteristics of shape and structure. We can use mathematical language to describe it, built iterated function systems and realize computer simulation.