ifs.py

Created on August 29, 2019

747 Bytes

Draws iterated functions fractals.

nb is the number of pixels drawn.

Draw a tree: m=350 w.append([[0,0],[0,.5]]); b.append([[0],[0]]); p.append(.05) w.append([[.42,-.42],[.42,.42]]); b.append([[0],[.2]]); p.append(p[-1]+.4) w.append([[.42,.42],[-.42,.42]]); b.append([[0],[.2]]); p.append(p[-1]+.4) w.append([[.1,0],[0,.1]]); b.append([[0],[.2]]); p.append(1)

def ifs(nb):
 from random import random
 import kandinsky

 def vecprod(M,V):
  nlM=len(M)
  return [[sum([l[j]*V[j][0] for j in range(nlM)])] for l in M]

 def vecadd(v1,v2):
  return [[v1[i][0]+v2[i][0]] for i in range(len(v1))]

 w=[];b=[];p=[]

 # Fougere
 m=15
 w+=[[[0,0],[0,.16]]];b+=[[[0],[0]]]; p+=[.01]
 w+=[[[.85,.04],[-.04,.85]]]; b+=[[[0],[2]]]; p+=[p[-1]+.85]
 w+=[[[.2,-.26],[.23,.22]]]; b+=[[[0],[1]]]; p+=[p[-1]+(1-p[-1])/2]
 w+=[[[-.15,.28],[.26,.24]]]; b+=[[[0],[.9]]]; p+=[1]

 n=len(w)

 def choix(x):
  h=random()
  i=0
  while True:
   if h<=p[i]:
    return vecadd(b[i],vecprod(w[i],x))
   i+=1

 x=[[0],[0]]

 for _ in range(nb):
  x=choix(x)
  kandinsky.set_pixel(160+int(m*x[0][0]),220-int(m*x[1][0]),(0,0,0))