坐标轴显示特定范围

 hold on
for i = 1:5
plot([-10,20],[0.2*i,0.2*i])
 hold on
 end
 plot([3,3],[0,1])
xlabel('[ev]')
 set(gca,'xtick',(-10:1:20))
 axis([-10 20 0 1])