Re: [R-sig-Geo] variogram using gstat

2008-05-09 Thread Edzer Pebesma
I don't know of any general guidelines here. I would settle with a reasonable number of point pairs (preferably over 20) per lag. -- Edzer PUJAN RAJ REGMI wrote: Dear sir, Thank you very much for the help. I would like to ask another question regarding the width selection. For omni

[R-sig-Geo] Vacancies for 2 Scientific Programmers, Computational Geo-Ecology, Amsterdam

2008-05-09 Thread Tomislav Hengl
The Computational Geo-Ecology (CGE) research group of the University of Amsterdam is looking for two enthusiastic Scientific Programmers who will develop virtual laboratories that support data analyses and modelling. This concerns data exploration through

Re: [R-sig-Geo] Calculation of geographical slope

2008-05-09 Thread Roger Bivand
On Wed, 7 May 2008, May, Roel wrote: Hi all, Does anyone know if there exists a function in R that can calculate geographical slope and aspect (i.e. like elevational slope/aspect) on grid values? I'd suggest pushing the DEM out to GRASS, and using the module there. It could be done by

Re: [R-sig-Geo] SpatialPolygonsDataFrame converted to SpatialPolygons after union

2008-05-09 Thread Roger Bivand
On Fri, 9 May 2008, Oscar Breugelmans wrote: Dear list, I have a postal code map of the Netherlands. I use the area code PC4NR as the identifier for each area. After making a subset of the areas, I use unionSpatialPolygons to combine the polygons (areas) that have a different ID, but the same