Julia语言

function mandel(z)
    c = z
    max = 80
    for n = 1:max
        if abs(z) > 2
            return n-1
        end
        z = z^2 + c
    end
    return max
end

using LinearAlgebra: tr
using Statistics #导入std, mean等函数

function randmatstat(t)
    n = 5
    v = zeros(t)
    w = zeros(t)
    for i = 1:t
        a = randn(n,n)
        b = randn(n,n)
        c = randn(n,n)
        d = randn(n,n)
        P = [a b c d]
        Q = [a b; c d]
        v[i] = tr((P'*P)^4)
        w[i] = tr((Q'*Q)^4)
    end
    std(v)/mean(v), std(w)/mean(w)
end