How can I add noise in this matlab spiral plot ??
t = linspace(0,6*pi,1000);
x = t.*cos(t);
y = t.*sin(t);
h = plot(x,y);
set(h(1),'linewidth',20);
set(h(1),'LineStyle','--');
k = 0.2;
x = t.*cos(t) + k*(rand(size(t))-0.5);
y = t.*sin(t) + k*(rand(size(t))-0.5);
fiddle with k
to adjust the amplitude of your noise.