Rich Wareham's Julia set code

juliasets.jl

# Copyright (c) 2017: Rich Wareham, Simon Byrne
# Available under the MIT "Expat" license.

using Colors
using SenseHat

const LED = led_matrix()

function julia(z, c)
    maxit = 50
    cols = [RGB(HSV(360*h, 1, sqrt(h))) for h in linspace(0, 1, maxit)]    
    for it in 1:maxit
        z = z^2 + c        
        if abs(z) > 2
            return cols[it]
        end
    end    
    cols[end]
end

function julia_render(n)
    for a in linspace(0, n*2*pi, 200*n)
        r = sin(0.5 + a/2)
        cx = sin(a) * r
        cy = cos(a/3) * r
        LED[:] = [julia(zx + im*zy, cx+im*cy) for zx in linspace(-1, 1, 8), zy in linspace(-1, 1, 8)]
    end
end

julia_render(5)