Thanks for that hint which pretty much solves my problem.

I am passing a spatial object to plot which is why I had thought that
spplot was ultimately called.

It appears that plot() and its parameters are in charge of setting the plot
area no matter what kind of object is passed in.

Regards,

Jon

On Mon, Nov 28, 2011 at 12:52 PM, Edzer Pebesma <
edzer.pebesma@uni-muenster.de> wrote:

> It seems that your question has nothing to do with spplot (which is a
> method in package sp), as you are using plot(). If the problem is
> similar to this:
>
> > plot(1:10,xlim=c(0,11),ylim=c(0,11))
> > par()$usr
> [1] -0.44 11.44 -0.44 11.44
>
> then it doesn't have to do anything with plotting map data, and r-help
> might be the more suitable list to ask. The following might help:
>
> > plot(1:10,xlim=c(0,11),ylim=c(0,11),xaxs="i", yaxs="i")
> > par()$usr
> [1]  0 11  0 11
>
> Best regards,
>
> On 11/28/2011 09:20 PM, Jonathan Callahan wrote:
> > I am plotting spatial data on transparent backgrounds for overlay on top
> of
> > a GoogleMaps interface but they aren't *exactly* right.
> >
> > I have set the size of GoogleMaps and my image to 640X640 and I receive
> > bounds information on the current region from the GoogleMaps javascript
> API.
> >
> > The problem is that the image generated by spplot does not strictly
> adhere
> > to the xlim and ylim parameters I am passing in.
> >
> > As an example, here is some debugging of a plot of watershed basins
> >
> >   print(paste("map_west = ",w,", map_east =",e,", map_south = ",s,",
> > map_north = ",n))
> >   xlim = c(w,e)
> >   ylim = c(s,n)
> >   plot(basin,xlim=xlim,ylim=ylim,border=col_basin,lwd=lwd_basin)
> >   print(paste("usr_west = ",format(par()$usr[1],digits=7,nsmall=4),",
> > usr_east =",format(par()$usr[2],digits=7,nsmall=4),
> >               ", usr_south = ",format(par()$usr[3],digits=6,nsmall=4),",
> > usr_north = ",format(par()$usr[4],digits=6,nsmall=4)))
> >
> > And here is the resulting text output:
> >
> > [1] "map_west =  -124.4348 , map_east = -123.6252 , map_south =  43.8856
> ,
> > map_north =  44.4652"
> > [1] "usr_west =  -124.4672 , usr_east = -123.5928 , usr_south =  43.8618
> ,
> > usr_north =  44.4890"
> >
> >
> > Things are close but not *exactly* right. Is there anything I can do to
> > force spplot to stick to the boundaries I have passed in?
> >
> > I am using R 2.13.1 and sp 0.9-85.
> >
> > Thanks in advance.
> >
>
> --
> Edzer Pebesma
> Institute for Geoinformatics (ifgi), University of Münster
> Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251
> 8333081, Fax: +49 251 8339763  http://ifgi.uni-muenster.de
> http://www.52north.org/geostatistics      e.pebesma@wwu.de
>
> _______________________________________________
> R-sig-Geo mailing list
> R-sig-Geo@r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>



-- 
Jonathan Callahan, PhD
Mazama Science
206-708-5028
mazamascience.com

	[[alternative HTML version deleted]]

