r=1;theta=[linspace(0,2*pi,200),2*pi];xx=cos(theta);yy=sin(theta);numindex=randperm(7);plot(2*r*xx,2*r*yy); %外圆hold onplot(r*xx,r*yy,'--'); %虚线圆plot(r*xx/3,r*yy/3); %原点的小圆text(0,0,num2str(nu...