Christmas tree IFS

Written by Paul Bourke
January 2002

The IFS equations are as follows

xn+1 = a xn + b yn + e

yn+1 = c xn + d yn + f

The parameter table: 
                   set 1       set 2      set 3  
             a     0.0         0.0        0.5
             b    -0.5         0.5        0.0
             c     0.5        -0.5        0.0
             d     0.0         0.0        0.5
             e     0.5         0.5        0.25
             f     0.0         0.5        0.5
   probability     1/3         1/3        1/3