search for: tri2nb

...be able to store the test results as lines of a matrix, that I would latter be able to export as a dataset. My problem is that I'm not sure how I could do this using R. Any help will be much appreciated. All the very best, JP coords2 <- as.matrix(jcdist.data[1:87, 6:7]) col.tri.nb<-tri2nb(coords2) for(n in c(1,88,175,262,349)) { f<- n+86 work <- jcdist.data[n:f, 10:12] res <-moran.test(spNamedVec("res1", work), nb2listw(col.tri.nb, style="W")) moran<-res$estimate[1] upper<-res$estimate[1] + (qnorm(0.025, lower.tail=FALSE) *sqr...

...ested in evaluating measures of spatial autocorrelation to flag plates for corrections. I have been using moran.test and geary.test from the spdep package. My approach is as follows: ## plate is a matrix of data coords <- expand.grid(1:32, 1:48) x <- as.numeric(plate) moran.test(x, nb2listw(tri2nb(coords))) While this works and seems to give me reasonable results, I am not specifying a weight matrix and am imposing a triangulation on my grid. My questions are: 1. Has anybody done something like this before, in the context of high throughput screening? 2. I'd like to specify that for a...

Hi R helpers, Is there a function (package?) in R available which tests "spatial autocorrelation" between points (e.g. vector layer of weather stations)? (e.g. Moran's I...) Via the archives we found out that there is a package 'spdep' which uses grid data for testing spatial autocorrelation. Thanks a lot, Jan

Hi group, I'd like to do spatial analysis of my data using the spdep package. It appears that a file of class nb is necessary, but I do not find what that should look like and if there is a function that creates such file for me. How can I create a nb-object of my data points? Thanks, René Eschen. [[alternative HTML version deleted]]

hi,friends, we all know that moran's I index and Geary'C index can be used to test spatial autocorrelation in both the area data and point data, but i only can find something on how to calculate on the data of area, and can't find the methods to perform it on the point data, could anybody give me some information, thanks in advance! -- Kind Regards, Zhi Jie,Zhang ,PHD Department of

hello, I want to do a test for spatial correlation. I tried it with geary.test() but I don't understand the required input. x= a numeric vector the same length as the neighbours list in listw (my sampled data, I assume) listw= a listw object created for example by nb2listw (well when I check nb2listw() I get to "neighbours - an object of class nb" - but I couldn't figure

Hello List, I'm a very new user to the R system. I'm only beginning to learn the basics, but so far I've been able to do little more than try a few examples, and of course begin reading the documentation. My primary motivation for exploring R is the availability of tools like the 'spdep' package for calculating spatial statistics such as Geary's C and Moran's

Dear list, (also sent to Roger Bivand, but perhaps somebody of you can help me also) I am trying to use package spdep for fitting an SAR model with errorsarlm. However, I am not sure how to make a valid nb object out of my neighborhood. As far as I have seen, there is no documentation for nb.object. I have done the following: class(pschmid$nb) <- "nb" # pschmid is a prab object as