没看懂你在说什么……

啥意思？？？

1) to get the overlap plot, you can do the following:
plot(....);
par(new=T);
plot(.....);

2) to get the same range, you need to specify the same axis (e.g. ylim = c(0,1),xlim=c(0,1), etc.) for each plot

Hope this help.

十分感谢。

Thank you in this Thanksgiving Day!