There are some functions that will do this in 1 step, like matplot if the the 
data is formatted properly.  ggplot has already been mentioned as another 
approach.

If you want to stick with base graphics, there is a zoomplot function in the 
TeachingDemos package that will rescale a plot (zoom in or out) and works in 
this case:

> library(TeachingDemos)
>
> a<-rnorm(5)
> b<-rnorm(5)
> plot(a,b,col = "red")
> points(10,-10)
>
> zoomplot( range(a,10), range(b,-10) )
>

If you want this a little more automatic, you can easily write a function which 
does the zooming and plotting both,  a simple version of the function would be:


> expandpoints <- function(x, y, ... ) {
+ usr <- par('usr')
+ zoomplot( range(x,usr[1:2]), range(y,usr[3:4]) )
+ points(x,y,...)
+ }
>
> plot(a,b,col="red")
> expandpoints(10,-10)
>

If you are going to use this much, it should be modified to accept the same 
types of input as points and possibly do some other checking.  Note also that 
this will be adding a little extra area around the old points as well unless 
the axis style is changed.

Hope this helps,


--
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
[EMAIL PROTECTED]
801.408.8111


> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> project.org] On Behalf Of Haoda Fu
> Sent: Thursday, October 16, 2008 10:07 PM
> To: r-help@r-project.org
> Subject: [R] R plot
>
> All -
>
>
> When I plot something like
>
> a<-rnorm(5)
> b<-rnorm(5)
> plot(a,b,col = "red")
> points(10,-10)
>
> The last point is missing because it is out of
> range of the first plot.
>
> I just try to switch from Matlab to R. In Matlab,
> it always can automatic adjust the xlim and ylim
> for such case.
>
> Is it possible auto adjust in R? Otherwise
> keep tracking xlim and ylim is really annoying.
>
> Best,
> Haoda
>
> ______________________________________________
> R-help@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-
> guide.html
> and provide commented, minimal, self-contained, reproducible code.

______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Reply via email to