The Sierpinski triangle implemented in MATLAB

Here is the code used to generate the triangle above:

n = 1000 %input('number of iterations? ')

m=2; xi=zeros(n);yi=zeros(n);

for m = 2:n

    r = randi([1 3]);

    

    switch r

        case 1

            xi(m)=.5*xi(m-1);

            yi(m)=.5*yi(m-1);

        case 2

            xi(m)=.5*xi(m-1)+.25;

            yi(m)=.5*yi(m-1)+sqrt(3)/4;

        case 3

            xi(m)=.5*xi(m-1)+.5;

            yi(m)=.5*yi(m-1);

    end

end

plot(xi,yi,'^')