Spatial auto-correlation globally (sphere)
On Sun, 23 Mar 2014, Alex Mandel wrote:
Has anyone seen a method for creating a neighbor list, for use in spatial auto-correlation tests, that treats the earth as a sphere so that relationships can go shortest distance. I'm trying to make a neighbor list of all countries in the world.
Please start by specifying the support you intend to use (centroid point support, polygonal support, what?). If point support, setting longlat=TRUE in dnearneigh() in spdep with a matrix of coordinates, or using an object inheriting from SpatialPoints with the appropriate CRS will give you Great Circle distances; polygons are more complicated. Have you looked at the cshapes package, also mentioned in the Spatial Task View, which appears to do what you want to do? It has an R Journal article: http://journal.r-project.org/archive/2010-1/RJournal_2010-1_Weidmann+Skrede~Gleditsch.pdf Roger
Yes I realize that the relatedness may not be distance and I might weight on some other factor but I need the neighbor list to start. Example, US <-> Japan, China or Russia should be a line across the Pacific Perhaps I need to develop the neighbor list using some sort of social diagramming tool instead. Any leads would be appreciated. Thanks, Alex
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Roger Bivand Department of Economics, Norwegian School of Economics, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 91 00 e-mail: Roger.Bivand at nhh.no