[R-sig-Geo] measuring angle or relative direction of 2 lines

2011-10-17 Thread Tracey Osborne
measuring the angle between intersecting lines: Does anyone know of any helpful tools/methods in R for measuring the angle between two intersecting lines in a map or an equation that would do so with the start and end latitudes and longitudes of the two lines? Or give directions of lines?

Re: [R-sig-Geo] Creating big raster from small tiles

2011-10-17 Thread steven mosher
Thanks, I basically have to reclass() all 72 tiles, then aggregate() them from 30 arc seconds to 5 minutes and eventually put them in a brick with other rasters so I can average across the layers. I thought unionExtent() was going to be the ticket, but that just effects the extent.

Re: [R-sig-Geo] errors in installing HDF5 package under windows

2011-10-17 Thread Paul Hiemstra
On 10/16/2011 02:10 PM, zhijie zhang wrote: cygwin warning: MS-DOS style path detected: C:/PROGRA~1/R/R-213~1.2/bin/i386/HDF5~1.RCH/hdf5/libs Preferred POSIX equivalent is: /cygdrive/c/PROGRA~1/R/R-213~1.2/bin/i386/HDF5~1.RCH/hdf5/libs CYGWIN environment variable option

Re: [R-sig-Geo] Delete points within a certain distance of each other

2011-10-17 Thread Mathieu Rajerison
spatstat::nndist? 2011/10/17 Paul Hiemstra paul.hiems...@knmi.nl On 10/15/2011 02:57 PM, Sandeep Patil wrote: Hello all I have about 4500 spatial points which are irregularly spaced... What is want to do is to replace points that are clustered very near each other by one point

Re: [R-sig-Geo] IDW example

2011-10-17 Thread Ashton Shortridge
On 10/16/11, Hodgess, Erin, wrote: Dear R Sig Geo People: Here is probably a dumb question, so please forgive me in advance (or swear, whatever is most appropriate): could someone recommend a good reference on IDW that has a numeric example, please? Sure, check out Paul Bolstad's GIS

Re: [R-sig-Geo] IDW example

2011-10-17 Thread Peter Larson
Believe it or not, the Wikipedia entry has the formula listed. You can easily try it out yourself. It's such a simple procedure that it can be done by hand. http://en.wikipedia.org/wiki/Inverse_distance_weighting Pete On 10/16/11, Hodgess, Erin hodge...@uhd.edu wrote: Dear R Sig Geo People:

Re: [R-sig-Geo] IDW example

2011-10-17 Thread giuseppe calamita
Hi Erin, did you check the book from Roger Bivand -Edzer Pebesma and Gomez-Rubìo: Applied spatial data analysis with R? There is some short explanation of how the algorithm work and just one record of code. If you want I think I can send you some line of codes as examples. Giuseppe

Re: [R-sig-Geo] IDW example -- gstat, spatstat

2011-10-17 Thread Edzer Pebesma
You are right -- google pointed me to the example: http://www.asdar-book.org/book/vis_mod.R chunk 31, where the function krige, without variogram model, results in idw. To avoid confusing scripts that suggest kriging takes place, package gstat also provides a function idw, which does the same

Re: [R-sig-Geo] multitype point patterns

2011-10-17 Thread Marcelino de la Cruz
Hi Aurelie, Try this: skate.ppp$marks - data.frame(species=skate.ppp$marks, number=skate$number) HTH, MArcelino At 17:41 17/10/2011, GodinA wrote: Hi all, I have a multitype point patterns representing 12 different species as follow: marked planar point pattern: 821 points multitype,

Re: [R-sig-Geo] multitype point patterns

2011-10-17 Thread GodinA
Awesome! Thank you very much MArcelino! - Aurelie Cosandey-Godin Ph.D. Candidate, Department of Biology Industrial Graduate Fellow, WWF-Canada Dalhousie University | Biology Dept. |Halifax, NS, Canada Email: god...@dal.ca | Web: wormlab.biology.dal.ca