[R] plotting points to a map

[Sarah Goslee]

Hi,

On Wed, Jul 18, 2012 at 2:11 PM, Gary Dong <pdxgary163 at gmail.com> wrote:
> Dear R users,
>
> I have a city map in shape file (polygon). I also have some points that I
> hope to plot them to the city map.

What projection is the shape file in? Have you successfully imported
it into R yet?

This page has a nice overview on dealing with shapefiles in R.

http://www.nceas.ucsb.edu/scicomp/usecases/ReadWriteESRIShapeFiles


> The only information I have about those
> points are their relative longitude and latitude to the city center by
> miles. Is there a way that R can help me to do this? Thanks.

What does "relative longitude and latitude in miles" mean? That makes
no sense to me. Do you mean distance and direction? (Which wouldn't be
latitude and longitude.)

If the latter, do you know the coordinates of the reference point?

I think we need more information to be able to help. You might also be
better served by asking on the r-sig-geo list instead of the main
R-help list.

Sarah

-- 
Sarah Goslee
http://www.functionaldiversity.org