Binet Matt Parker

binet.jl

using Plots

const Φ = (1+√5)/2
const ξ = (1-√5)/2

function binet(n)
    c = Complex(n)
    return (Φ^c - ξ^c)/√5
end

function draw(r = -5:0.001:5)
    points = binet.(r)
    x = real.(points)
    y = imag.(points)
    plot(x,y; legend=false, framestyle = :zerolines)
end