Fig. 6. A two-dimensional lattice model of Fz6^-/- hair follicle orientation development. Each hair follicle is represented by a unit length vector placed at one of the vertices of a lattice of equilateral triangles. After the initial vector orientations are set, the lattice develops by repeated application of an updating rule, which specifies that each vector's orientation becomes modified by adding to it the vector sum of its 18 closest neighbors after that sum has been scaled to 2% of its magnitude. This number of neighbors corresponds to two concentric circles of surrounding lattice points. The starting configuration (0) is a set of randomly oriented vectors, and the lattice is shown after 10, 20 and 100 iterations of the local consensus algorithm. Each vector orientation is represented by the angle and color of the corresponding bar, as shown in the key to the right. Reproduced with permission from Wang et al. (Wang et al., 2006c).