# shortest realistic distance for fish travel

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## shortest realistic distance for fish travel

 Hi,         I am trying to find an algorithm or thoughts on approach for how to   compute the shortest realistic distance between two points.  I define   shortest realistic distance as the shortest distance between two   points that a fish (which is what I study) could move through.  Hence   the path must wrap around land, islands, archipelagos, etc. Point 1 41.15   N 71.26 W Point 2 42.17   N 70.37 W         I'm sure this issue has come up with the geo-statistical community,   but simply need a starting direction. Thank much and happy holidays. Jon Loehrke Graduate Research Assistant Department of Fisheries Oceanography School for Marine Science and Technology University of Massachusetts 200 Mill Road, Suite 325 Fairhaven, MA 02719 jloehrke at umassd.edu T 508-910-6393 F 508-910-6396
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## shortest realistic distance for fish travel

 Hi, That sounds like a least-cost path problem. Sarah On Thu, Dec 18, 2008 at 2:38 PM, Jon Loehrke wrote: > Hi, > >        I am trying to find an algorithm or thoughts on approach for how to > compute the shortest realistic distance between two points.  I define > shortest realistic distance as the shortest distance between two points that > a fish (which is what I study) could move through.  Hence the path must wrap > around land, islands, archipelagos, etc. > -- Sarah Goslee http://www.functionaldiversity.org
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## shortest realistic distance for fish travel

 In reply to this post by Jon Loehrke On Thursday 18 December 2008, Jon Loehrke wrote: > Hi, > > I am trying to find an algorithm or thoughts on approach for how to > compute the shortest realistic distance between two points.  I define > shortest realistic distance as the shortest distance between two > points that a fish (which is what I study) could move through.  Hence > the path must wrap around land, islands, archipelagos, etc. > > Point 1 > > 41.15   N > 71.26 W > > Point 2 > > 42.17   N > 70.37 W > > I'm sure this issue has come up with the geo-statistical community, > but simply need a starting direction. > > Thank much and happy holidays. Hi, This isn't a geo-statistics approach, but simple cost-surface algorithms should be able to do this without too much work. An example in GRASS: http://casoilresource.lawr.ucdavis.edu/drupal/node/544You could make the non-water regions a 'really high' static cost, such that finding the least-cost path would be constrained to water. Cheers, Dylan > Jon Loehrke > Graduate Research Assistant > Department of Fisheries Oceanography > School for Marine Science and Technology > University of Massachusetts > 200 Mill Road, Suite 325 > Fairhaven, MA 02719 > jloehrke at umassd.edu > T 508-910-6393 > F 508-910-6396 > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo at stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo-- Dylan Beaudette Soil Resource Laboratory http://casoilresource.lawr.ucdavis.edu/University of California at Davis 530.754.7341
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## shortest realistic distance for fish travel

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