Spider Algorithm
The spider algorithm computes the parameter of a quadratic polynomial from an external angle [2]. It works by iterating a "spider" — a collection of legs connecting the critical point to infinity — until convergence.
$2/9$
using Mandelbrot
using BrotViz
using CairoMakie
angle = 2//9
S0 = Mandelbrot.standardspider(angle)
list = Mandelbrot.spideriterates(S0, 20)
fig = Figure()
ax = Axis(fig[1, 1])
record(fig, "spider_2_9.gif", 1:20; framerate=3) do i
empty!(ax)
spiderplot!(ax, list[i])
end
Introduction
using Mandelbrot
using BrotViz
using CairoMakie
theta = 9//56
S = Mandelbrot.standardspider(theta)
fig = Figure()
ax = Axis(fig[1,1])
spiderplot!(ax,S)
fig
using Mandelbrot
K = KneadingSequence(4//15)|AAB*₁|References
- [2]
- J. H. Hubbard and D. Schleicher. The spider algorithm. In: Proceedings of Symposia in Applied Mathematics, Vol. 49, edited by R. Devaney (American Mathematical Society, Providence, Rhode Island, 1995); pp. 155–180.