[dazhangyu]

代码如下：
xPic=a;yPic=b; %a,b是实数，可能是正，也可能是负
plot(xPic,yPic,'pr','markersize',8,'MarkerFaceColor','r');%画点
str_ls=['(',num2str(xPic),',',num2str(yPic),')'];%点坐标字符串
text(xPic,yPic,str_ls);%%在图上标出点的坐标

问题：

每次必须重启MATLAB r2008, 否则报错：

??? Subscript indices must either be real positive integers or logicals.

为什么呢？