## Make a color representation of the
## logistic map. Previously, we used the
## position of cubes; here we vary the
## color.
from visual import *

a = 3.8          ### logistic map parameter
xA = 0.25        ### initial value of the "population" A
xB = 0.250001    ### initial value of the "population" B

boxa = box()       ### 2 separate cubes - start white
boxb = box(x = 2)
## color has red, green, blue components
boxa.blue = 0.
boxb.blue = 0.

while 1:
    rate(8)
    ## set colors of cubes, depending on xA, xB
    boxa.red = xA              ## shade cube a with a
    boxa.green = 1.0 - boxa.red   ## color dependent on xA
    boxb.red = xB              ## same with b, xB
    boxb.green = 1.0 - boxb.red   ## if xB is near 1, mostly red
                            ## if xB is near 0, b greenish
    ## alternatively, could use RGB assignment, something
    ## like a.color = (xA, 1.0-xA, 0.)
    ## now update variables, using logistic map
    xA = a * xA * (1. - xA)
    xB = a * xB * (1. - xB)