Hi 1. I have two raster files *.asc (identical size) 2. The data in each contain presence or absence data in each cell represented by a 1 or 0 respectively 3. I would like to take the location of each 1 (presence cell) in raster file 1 and measure the euclidean distance to the nearest 1 (presence cell) in raster file 2. Obviously in some cases there will be overlap so the distance will be zero. 4. I would like the output file to have each individual measurement on a seperate line in a single file. I am very new to R, so any help would be appreciated. Best regards Paul -- Paul Duckett - PhD Candidate Conservation Genetics Lab E8A 264 Biological Sciences Faculty of Science Macquarie University North Ryde NSW 2109 http://paulduckett.redbubble.com
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 05/04/11 03:43, Paul Duckett wrote:> HiHi> > 1. I have two raster files *.asc (identical size)This question is much more appropriate for the r-sig-geo mailing list (https://stat.ethz.ch/mailman/listinfo/r-sig-geo), which focusses on spatial analysis / modelling in R. I am sure you will get an answer there. I take the liberty to CC this mail to the list - and I would encourage you to subscribe to the mailing list. Cheers, Rainer> 2. The data in each contain presence or absence data in each cell > represented by a 1 or 0 respectively > 3. I would like to take the location of each 1 (presence cell) in > raster file 1 and measure the euclidean distance to the nearest 1 > (presence cell) in raster file 2. > > Obviously in some cases there will be overlap so the distance will be zero. > > 4. I would like the output file to have each individual measurement on > a seperate line in a single file. > > > I am very new to R, so any help would be appreciated. > > Best regards > Paul- -- Rainer M. Krug, PhD (Conservation Ecology, SUN), MSc (Conservation Biology, UCT), Dipl. Phys. (Germany) Centre of Excellence for Invasion Biology Natural Sciences Building Office Suite 2039 Stellenbosch University Main Campus, Merriman Avenue Stellenbosch South Africa Tel: +33 - (0)9 53 10 27 44 Cell: +27 - (0)8 39 47 90 42 Fax (SA): +27 - (0)8 65 16 27 82 Fax (D) : +49 - (0)3 21 21 25 22 44 Fax (FR): +33 - (0)9 58 10 27 44 email: Rainer at krugs.de Skype: RMkrug -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk2a0sUACgkQoYgNqgF2egqpqACfa2FdwXYwn7i+woC6RnFnURE8 p2kAn1Q833jkNyG9EfkQUIoycsdlDJWp =aykq -----END PGP SIGNATURE-----
Dear Paul,
The command
RSiteSearch("nearest neighbour")
Will give you the answer that you need. (The second hit is the function you
want).
Best regards,
Thierry
----------------------------------------------------------------------------
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek
team Biometrie & Kwaliteitszorg
Gaverstraat 4
9500 Geraardsbergen
Belgium
Research Institute for Nature and Forest
team Biometrics & Quality Assurance
Gaverstraat 4
9500 Geraardsbergen
Belgium
tel. + 32 54/436 185
Thierry.Onkelinx at inbo.be
www.inbo.be
To call in the statistician after the experiment is done may be no more than
asking him to perform a post-mortem examination: he may be able to say what the
experiment died of.
~ Sir Ronald Aylmer Fisher
The plural of anecdote is not data.
~ Roger Brinner
The combination of some data and an aching desire for an answer does not ensure
that a reasonable answer can be extracted from a given body of data.
~ John Tukey
> -----Oorspronkelijk bericht-----
> Van: r-help-bounces at r-project.org
> [mailto:r-help-bounces at r-project.org] Namens Paul Duckett
> Verzonden: dinsdag 5 april 2011 3:44
> Aan: R-help at r-project.org
> Onderwerp: [R] Euclidean Distance in R
>
> Hi
>
> 1. I have two raster files *.asc (identical size) 2. The data
> in each contain presence or absence data in each cell
> represented by a 1 or 0 respectively 3. I would like to take
> the location of each 1 (presence cell) in raster file 1 and
> measure the euclidean distance to the nearest 1 (presence
> cell) in raster file 2.
>
> Obviously in some cases there will be overlap so the distance
> will be zero.
>
> 4. I would like the output file to have each individual
> measurement on a seperate line in a single file.
>
>
> I am very new to R, so any help would be appreciated.
>
> Best regards
> Paul
> --
> Paul Duckett - PhD Candidate
> Conservation Genetics Lab
> E8A 264
> Biological Sciences
> Faculty of Science
> Macquarie University
> North Ryde
> NSW 2109
> http://paulduckett.redbubble.com
>
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> PLEASE do read the posting guide
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> and provide commented, minimal, self-contained, reproducible code.
>