You may want to use the ggplot2 package for this (see ?coord_map), it can combine maps and other plots and does a lot of the thinking about scaling and projections for you.
-- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare greg.s...@imail.org 801.408.8111 > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- > project.org] On Behalf Of cassie jones > Sent: Sunday, February 13, 2011 7:15 PM > To: r-help@r-project.org > Subject: [R] how to overlay a map of US on image plot > > Dear all, > > I have a data set which has latitude, longitude (not in increasing > order) > and observed precipitation corresponding to those locations. I am using > image.plot command for that. But I want to overlay a map of US on that > plot. > I know we can use map('usa') to draw it, but I dont know how can I > overlay > it on the plot of the precipitation data. Can anyone please help me > with it? > > > Thanks in advance. > > Cassie. > > [[alternative HTML version deleted]] > > ______________________________________________ > 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.