Just answered with Robert Hijmans in GEOstat course: r=raster(c) does not necessarily use the extent of c, so the correct way to have a raster with the extent of a group of coordinates should be r= raster(extent(c))
Cheers Agus 2014-06-11 21:56 GMT+02:00 Agus Camacho <agus.cama...@gmail.com>: > Hi all, > > Could anybody tell me why this happens? > When I generate a raster from a group of coordinates, it leaves some > outside of it. changing the cell size of the raster and increasing the > extent of the raster did not solve the problem. > > There goes a reproducible example, > Thanks in advance and see (some of) you soon. > > > brownian=function(n=1000,fun=rnorm) > { > x<-cumsum(fun(n)) > y<-cumsum(fun(n)) > coor=data.frame(x,y,id) > return(coor) > } > > require(raster) > require(sp) > c=coords=brownian(50,fun=rnorm) > coordinates(c)=c(1,2) > r=raster(c) > cellsiz=3 > res(r) <- cellsiz > extend(r, c(1,0)) > p= rasterToPolygons(r) > plot(p) > points(coords,col="black") > cellFromXY(r, coords) > > > -- > Agustín Camacho Guerrero. > Doutor em Zoologia. > Laboratório de Herpetologia, Departamento de Zoologia, Instituto de > Biociências, USP. > Rua do Matão, trav. 14, nº 321, Cidade Universitária, > São Paulo - SP, CEP: 05508-090, Brasil. > -- Agustín Camacho Guerrero. Doutor em Zoologia. Laboratório de Herpetologia, Departamento de Zoologia, Instituto de Biociências, USP. Rua do Matão, trav. 14, nº 321, Cidade Universitária, São Paulo - SP, CEP: 05508-090, Brasil. [[alternative HTML version deleted]]
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