Devaney's Backward Iteration Algorithm

An algorithm for finding the Julia Set. This is based on the fact that the set of preimages of any point on the complex plane except 0 is dense in the Julia Set. So we pick any point on the complex plane except 0 and compute backward orbits. We eliminate the first 50.

Choose a complex number, x0 + y0i, and the parameter c = c0 + c1i.

For i = 1 to 15000 do
		w0 = x0-c0
		w1 = x1-c1
		let theta = argument of the complex number w0 + w1i
		let r = modulus of the complex number w0 + w1i
		let t = 0 or 1
		let theta = theta/2 + t*pi
		x0 = r cos(theta)
		y0 = r sin(theta)
		if (i > 50) then
		display pixel
		end if
end for