[GRASS-user] Selecting n cells more then minDist apart

Rainer M Krug r.m.krug at gmail.com
Wed Jan 25 06:10:28 EST 2012


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Hi

I need to select n cells on a raster map with no cell closer then
minDist from any other selected cell. The distances can be larger - no
problem - but they must not be smaller then minDist.

I looked at r.random.cell with using distance= as the min distance,
but if I select randomly n cells from the set generated, I get cells
with a multiple of minDist apart - not exactly what I am looking for.

I could use r.random and iterate until my requirements are met, but
that strikes me as extremely inefficient. Are thare any other ways of
achieving this?

As I am doing the calculations from R, I could also easily use R directly.

Any pointers are welcome,

Rainer

- -- 
Rainer M. Krug, PhD (Conservation Ecology, SUN), MSc (Conservation
Biology, UCT), Dipl. Phys. (Germany)

Centre of Excellence for Invasion Biology
Stellenbosch University
South Africa

Tel :       +33 - (0)9 53 10 27 44
Cell:       +33 - (0)6 85 62 59 98
Fax :       +33 - (0)9 58 10 27 44

Fax (D):    +49 - (0)3 21 21 25 22 44

email:      Rainer at krugs.de

Skype:      RMkrug
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