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Euclidean Distance in R

3 messages · Paul Duckett, Rainer M Krug, ONKELINX, Thierry

Paul Duckett
# 
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
Rainer M Krug
# 
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On 05/04/11 03:43, Paul Duckett wrote:
Hi
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
- -- 
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
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Fax (FR):   +33 - (0)9 58 10 27 44
email:      Rainer at krugs.de

Skype:      RMkrug
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ONKELINX, Thierry
# 
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