R help - Jul 2011 - calculating distance inland from coastline

Hi All, 

Does anybody know of any existing functions that will calculate distance
inland from a coastline?

It's possible to test if a lon,lat location is land or sea using
map.where(), but I need to add a buffer to this of say 2km, to allow for
points that are just on the coast, and below the resolution of the
worldHires database.

I'm working with a marine mammal satellite telemetry dataset and wish to
filter out spurious locations on land.

On another issue, does anybody know of any free vector map datasets that are
more up to date and have a higher resolution than the worldHires database
from the 'maps' package.

Thanks, Simon 



--
View this message in context:
http://r.789695.n4.nabble.com/calculating-distance-inland-from-coastline-tp3667464p3667464.html
Sent from the R help mailing list archive at Nabble.com.

Hi Simon
 
A combination of functions gDistance, gBuffer and gIntersects from package rgeos
should do the job. Also, have a look at www.naturalearthdata.com. They have
various shapefiles with coastlines and land polygons, though I don't know
how the resolution compares with the worldHires database.
 
Cheers,
Francois Rousseu
 
> Date: Thu, 14 Jul 2011 05:43:23 -0700
> From: s.j.goodman@leeds.ac.uk
> To: r-help@r-project.org
> Subject: [R] calculating distance inland from coastline
> 
> Hi All, 
> 
> Does anybody know of any existing functions that will calculate distance
> inland from a coastline?
> 
> It's possible to test if a lon,lat location is land or sea using
> map.where(), but I need to add a buffer to this of say 2km, to allow for
> points that are just on the coast, and below the resolution of the
> worldHires database.
> 
> I'm working with a marine mammal satellite telemetry dataset and wish
to
> filter out spurious locations on land.
> 
> On another issue, does anybody know of any free vector map datasets that
are
> more up to date and have a higher resolution than the worldHires database
> from the 'maps' package.
> 
> Thanks, Simon 
> 
> 
> 
> --
> View this message in context:
http://r.789695.n4.nabble.com/calculating-distance-inland-from-coastline-tp3667464p3667464.html
> Sent from the R help mailing list archive at Nabble.com.
> 
> ______________________________________________
> 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.
 		 	   		  
	[[alternative HTML version deleted]]