David, Thanks for the info and the references. I don't think I want to weight the kernel by the distance from shore since sometimes they are right on the shoreline (2 ft. of water), and they should have high UD's very close to shore. I was hoping there would be an easy way to constrain the area available, but no one has offered any. Second option is to cut out the land from the kernel distribution. Any idea if this is possible?
Thanks, Tim Tim Clark Department of Zoology University of Hawaii --- On Wed, 5/13/09, Pinaud David <pin...@cebc.cnrs.fr> wrote: > From: Pinaud David <pin...@cebc.cnrs.fr> > Subject: Re: [R-sig-Geo] Constraining movements in adehabitat > To: "Tim Clark" <mudiver1...@yahoo.com>, R-sig-Geo@stat.math.ethz.ch > Date: Wednesday, May 13, 2009, 9:18 PM > Dear Tim, > > You can try several papers from Jason Matthioploulos, > among: > Matthiopoulos (2003) The use of space by animals as a > function of > accessibility and > preference - Ecological Modelling 159 239-268 > Matthiopoulos, J. 2003. Model-supervised kernel smoothing > for the > estimation of > spatial usage. – Oikos 102: 367–377. > Unfortunately, I don't know a R implementation to do this > directly. One > (quick and dirty) way could be to weight the output of the > Kernel > estimation by a raster representing distance to coast (or > ocean/continent)? > > Hope it helps > > David > > Tim Clark a écrit : > > Dear List, > > > > Sorry, this is a second attempt to post the same > message. My last one got scrubbed so I changed browser > options. Hopefully this one will make it! > > > > I am using the package adehabitat to analyze the > movement patterns and home range of the manta ray (Manta > birostris) in Hawaii. The manta rays in this study > stayed close to shore, often feeding along the shore line or > in small bays. Since they can not go on land (being > fish) their home range is obviously limited to the ocean > area. In calculating home range statistics, is there a > way to limit the avalible area to the ocean. I have > read through the papers on Adehabitat but have not found a > way to limit the area. The closest I have found is the > function buffer(). Have I missed something? Is > there a way to co > > > nstrain the movements so that kernels will only be > computed for data points located in the ocean? > > > > I appreciate your help and guidence. > > > > Tim > > > > > > > > Tim Clark > > PhD Student > > University of Hawaii > > Honolulu, HI 96816 > > > > _______________________________________________ > > R-sig-Geo mailing list > > R-sig-Geo@stat.math.ethz.ch > > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > > > > > > __________ Information from ESET Mail Security, > version of virus signature database 4073 (20090513) > __________ > > > > The message was checked by ESET Mail Security. > > http://www.eset.com > > > > > > > > > > > > > > -- > *************************************************** > David PINAUD > Ingénieur de Recherche "Analyses spatiales" > > Centre d'Etudes Biologiques de Chizé - CNRS UPR1934 > 79360 Villiers-en-Bois, France > poste 485 > Tel: +33 (0)5.49.09.35.58 > Fax: +33 (0)5.49.09.65.26 > http://www.cebc.cnrs.fr/ > > *************************************************** > > > > > __________ Information from ESET Mail Security, version of > virus signature database 4073 (20090513) __________ > > The message was checked by ESET Mail Security. > http://www.eset.com > > _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo
