On Sep 28, 2015, at 5:33 PM, Ed Siefker wrote:
> I'm trying to plot() over an existing plot() like this:
>
>> attach(mtcars)
>> plot(mpg, hp)
>> par(new=TRUE)
>> par("usr")
> [1] 9.46 34.84 40.68 346.32
>> plot(mpg, hp, col="red", axes=FALSE, xlim=par("usr")[1:2],
>> ylim=par("usr")[3:4], xlab="", ylab="")
>> par("usr")
> [1] 8.4448 35.8552 28.4544 358.5456
The default usr ranges are some factor (my hazy memory says 104%) of the range
of thex- and y-values unless you specify otherwise. This choice allows round
data-points to be displayed at the extremes. Why are you trying to muck with
the plot setup? The right way would be to use points().
>
> For some reason "usr" is changing, and so it's not plotting over the
> existing data in the right place.
>
> ______________________________________________
> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> 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.
David Winsemius
Alameda, CA, USA
______________________________________________
R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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.
