matlab画图,我想让三个子图的大小一样,怎么样设置
```figure
subplot(3,1,1)
plot(ds,'b','LineWidth',1)
hold on;
plot([a,a],'r--','LineWidth',1.5)
hold on
plot([b,b], 'g--','LineWidth',1.5)
hold on
plot([c,c],'m--','LineWidth',1.5)
hold on
plot([d,d],'c--','LineWidth',1.5)
hold on
plot([e,e], 'k--','LineWidth',1.5)
str1='\fontsize{12}\fontname{宋体}采样点';
xlabel(str1)
lgd = legend('标签1','标签2','标签3','标签4','标签5','标签6','Location','NorthOutside') % 注意这一行的句尾不加分号;可以显示legend的参数
lgd.NumColumns = 3;
lgd.Location='northoutside';
subplot(312)
plot(ds1,'b','LineWidth',1)
hold on;
plot([a,a],'r--','LineWidth',1.5)
hold on
plot([b,b], 'g--','LineWidth',1.5)
hold on
plot([c,c],'m--','LineWidth',1.5)
hold on
plot([d,d],'c--','LineWidth',1.5)
hold on
plot([e,e], 'k--','LineWidth',1.5)
str1='\fontsize{12}\fontname{宋体}采样点';
xlabel(str1)
subplot(313)
plot(ds2,'b','LineWidth',1)
hold on;
plot([a,a],'r--','LineWidth',1.5)
hold on
plot([b,b], 'g--','LineWidth',1.5)
hold on
plot([c,c],'m--','LineWidth',1.5)
hold on
plot([d,d],'c--','LineWidth',1.5)
hold on
plot([e,e], 'k--','LineWidth',1.5)
str1='\fontsize{12}\fontname{宋体}采样点';
xlabel(str1)
```