Re: [R-sig-Geo] distmap

2007-06-25 Thread Edzer J. Pebesma
Roger Bivand wrote: > On Mon, 25 Jun 2007, Agustin Lobo wrote: > >> I've tried (among other things): >>> limit1 <- read.shape("limit_PNSN2000.shp") >> Shapefile type: Polygon, (5), # of Shapes: 2 >>> limit1poly <- Map2poly(limit1) >>> limit1owin <- as(limit1poly,"owin") >> Error in .classEnv(thi

Re: [R-sig-Geo] distmap

2007-06-25 Thread Roger Bivand
On Mon, 25 Jun 2007, Agustin Lobo wrote: I've tried (among other things): limit1 <- read.shape("limit_PNSN2000.shp") Shapefile type: Polygon, (5), # of Shapes: 2 limit1poly <- Map2poly(limit1) limit1owin <- as(limit1poly,"owin") Error in .classEnv(thisClass) : unable to find an environment

Re: [R-sig-Geo] functions on kernel density estimation in pointpattern analysis

2007-06-25 Thread Roger Bivand
On Mon, 25 Jun 2007, Dan Putler wrote: Thanks, Dan, I agree that the bandwidths are the problem here. Often the image breaks settings are also very misleading for 2D density plots, so one needs to take care, as you show. Roger Hi Zhi Jie, Below are some changes to your code which should m

Re: [R-sig-Geo] functions on kernel density estimation in pointpattern analysis

2007-06-25 Thread zhijie zhang
Dear Roger Bivand,Tim Keitt, and Dan Putler, Thanks for your answers. I have tried density.ppp(spatstat) and kernel2d(splancs), but the results are not very satisfied. I think there should be a higher density in the blue part of the map in the attachment. My dataset has been put in the attachmen

Re: [R-sig-Geo] functions on kernel density estimation in pointpattern analysis

2007-06-25 Thread Dan Putler
Hi Zhi Jie, Below are some changes to your code which should make you much happier. It does involve the use of the RColorBrewer package to create a color palette that makes the plot a bit easier to see. As you can guess, the size of the standard deviation given to density.ppp was the probl

Re: [R-sig-Geo] ODP: ODP: spsample and NA

2007-06-25 Thread Edzer J. Pebesma
additional to the X = as(X, "SpatialPixelsDataFrame") etc. there's a helper function that toggles between them; try: fullgrid(X) = TRUE class(X) fullgrid(X) = FALSE class(X) -- Edzer Agustin Lobo wrote: > I understand, but how do I convert between one type and the other? > I've tried: > > x <-

Re: [R-sig-Geo] ODP: ODP: spsample and NA

2007-06-25 Thread Agustin Lobo
I understand, but how do I convert between one type and the other? I've tried: x <- GDAL.open("C:/ALOBO/dipu2006/STLL_VEG2006/ESTRAT3_OBAC.tif") ESTRAT3OBAC <- asSGDF_GROD(x, output.dim=c(118,189)) GDAL.close(x) [EMAIL PROTECTED]@data==55537]<- NA X <- ESTRAT3OBAC[seq(1,118,by=10),seq(1,189,by=10)

Re: [R-sig-Geo] distmap

2007-06-25 Thread Agustin Lobo
I've tried (among other things): > limit1 <- read.shape("limit_PNSN2000.shp") Shapefile type: Polygon, (5), # of Shapes: 2 > limit1poly <- Map2poly(limit1) > limit1owin <- as(limit1poly,"owin") Error in .classEnv(thisClass) : unable to find an environment containing class "polylist" > limit2

Re: [R-sig-Geo] newbie sp question

2007-06-25 Thread Edzer J. Pebesma
Roger Bivand wrote: > It may also be worth asking on the PostGIS list whether you could upload > your geometries to PostGIS and have GEOS do the measurement - if you have > access to the software and experience with it. It may be that it can > handle geographical coordinates. > I have to be

Re: [R-sig-Geo] ODP: ODP: spsample and NA

2007-06-25 Thread Edzer J. Pebesma
Not only to avoid NAs, but also to get approximately right sample size. Stratified sampling does not take place based on strata defined by attributes (map layers), but rather by dividing the area into square blocks (strata) and randomly sample (n=1) from each block. That is why the resulting sa

Re: [R-sig-Geo] functions on kernel density estimation in point patternanalysis

2007-06-25 Thread Rob Robinson
Have you had a look at package ks? It seems to do rather nice bivariate kernels, and (I think) generalises to other dimensions. Cheers Rob *** Want to know about Britain's birds? Try www.bto.org/birdfacts *** Dr Rob Robinson, Senior Population Biologist British Trust for Ornithology, The Nunner

Re: [R-sig-Geo] krige.bayes output

2007-06-25 Thread Edzer J. Pebesma
Is it possible to compute them experimentally, by computing the variance of the back-transformed simulations for each prediction location? -- Edzer Paulo Justiniano Ribeiro Jr wrote: > Dear Giovanna > > For certain values of the Box-Cox transformation it is not possible to > compute kriging varia