similar to: kernel density in space

Displaying 20 results from an estimated 5000 matches similar to: "kernel density in space"

2007 Oct 15
1
Distance matrix in SpDep-package
Hello everybody, I would like to use the SpDep-package (especially the Local Moran index analysis and the Getis-Ord statistics) in R for analysing my data. However, I don't have x-y coordinates, but my data is in a distance matrix format. Is it possible to use the SpDep package with predefined distances as well instead of letting the program determining the distance itself by the function
2007 Dec 17
1
polygon class in splancs package
Dear forum, I would like to use the kernel2d or spkernel2d in the Splancs-package, but it does not recognize my polygon data. "Error in kernel2d(as.points(ptsbin), polygonprov, h0 = 2, nx = 100, : " is the error message. Invalid poly argument The data are defined as follows: polgonprov<-list(x=polyprov$X, y=polyprov$Y) with X and Y coordinates in the Lambert1972
2013 Nov 29
1
mat2listw function
Hi all, I am attempting to create a weights object and perform a Moran I test as well. I have a very large spatial weights matrix (roughly 22,000x22,000) that was created in Excel and read into R, and I'm now trying to implement: library(spdep) SW=mat2listw(matrix) I am getting the following error: Error in if (any(x<0)) stop ("values in x cannot be negative"): missing value
2009 Jul 14
1
Error when sampling from SpatialLines
Dear forum,   I am working in R 2.9.1 and I am trying to sample locations from a network file. Reading in nor plotting is a problem, however when I am trying to sample from the file I get the following message:   nwlim<-readShapeLines("C:/Limburg_nwshape", proj4string=CRS("+init=epsg:31300")) plot(nwlim)   randacc<-spsample(nwlim,n=1000,"random")
2008 May 13
2
Permutations
Dear R-users, Is there an easy way to determine all possible vectors of length 21 with each entry having permutations from 0 to 4, instead of doing it like this? It really takes up too much time, and I am convinced that there exists something easier. Can you help me? Thank you in advance! Kind regards, Elke for (a in 0:4){ for (b in 0:4){ for (c in 0:4){ for (d in 0:4){
2003 Jul 11
0
spdep
Hi everyone, The Spatial Dependence (spdep) library, has a function called 'dnearneigh', which identifies neighbours of region points by Euclidean distance between lower (greater than) and upper (less than or equal to) bounds. The function returns a list of integer vectors giving the region id numbers for neighbours satisfying the distance criteria. I have used this to identify the
2013 Nov 27
0
trouble using mat2listw function to create spatial weights object
Hi all, I am attempting to create a weights object and perform a Moran I test as well. I have a very large spatial weights matrix (roughly 22,000x22,000) that was created in Excel and read into R, and I'm now trying to implement: library(spdep) SW=mat2listw(matrix) I am getting the following error: Error in if (any(x<0)) stop ("values in x cannot be negative"): missing value
2013 Apr 16
1
Spatial Ananlysis: zero.policy=TRUE doesn't work for no neighbour regions??
Hello, I'm new to R and to Spatial Analysis and got a problem trying to create a Spatial Weights Matrix. *I us the following code to create the Neighbourslist:* >library(maptools) >library(spdep) >library(rgdal) >location_County<- readShapePoly("....") >proj4string(location_County)<- CRS("+proj=longlat ellps=WGS84") >location_nbq<-
2004 Jun 22
1
k nearest neighbours
Hi there fellow R-users, Does anyone know of a function which does exactly what knearneigh{spdep} (finds the k nearest neighbours) does in the package spdep but for more than 2D data? Regards Wayne KSS Ltd Seventh Floor St James's Buildings 79 Oxford Street Manchester M1 6SS England Company Registration Number 2800886 Tel: +44 (0) 161 228 0040 Fax: +44 (0) 161 236 6305
2003 Dec 09
0
The spdep package
Hi, Here is a listw object z corresponding to the matrix W. I understand n, nn, S0, S1 and S2 in the weights constants summary. Is it simply so that n1 = n-1, n2 = n-2 and n3 = n-3? If this is true where they are needed? Just wondering Osmo > W [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [1,] 0 1 0 1 0 0 0 0 0 [2,] 1 0 1 0 1 0
2005 Aug 03
1
help for cell2nb and queencell in spdep package
Dear Dr. Bivand and R-users, I have a 5 by 5 grid, say, location[1:5,1:5], and I want to know the indices of 8 neighbours of each cell. For example, for location[2,2], its neighbour coordinates are [1,1:3], [2,1], [2,3] and [3,1:3]. Sometimes I also need to remove edge effects (torus = TRUE). I have tried "cell2nb" function in your spdep package. Here's my example: > neigh
2003 Jun 30
2
spatial correlation test
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
2008 Oct 08
1
Error in spdep: system is computationally singular
Hi all, I am trying to run an autologistic model using the function errorsarlm from spdep package. **I built an XY matrix extracting the two colums from matriz** coords1<-matriz[matriz$casos1==1, c(4,5)] coords1<-as.matrix(coords1) **I identify neighbours of region points** nb20<-dnearneigh(coords1,0,20,longlat=TRUE) ** I build a neighbours list with spatial weights**
2007 Dec 21
1
matrix to gal object
useR's I need transform the matrix wdat [,1] [,2] [,3] [,4] [,5] [,6] [1,] 0 1 0 1 1 0 [2,] 1 0 0 1 1 0 [3,] 0 0 0 0 1 1 [4,] 1 1 0 0 1 0 [5,] 1 1 1 1 0 0 [6,] 0 0 1 0 0 0 to gal object. How I do with spdep? Thanks in advance for the help. Bernardo. University of Concepci?.
2004 Aug 23
2
Reading GAL file
Greetings: I am trying to work with spdep (everything is "brand new" downloaded this morning). OS = Windows 2000 (also up to date). The code I am using follows: #example gal.county=read.geoda("lnpilnd.GAL", row.names=NULL, skip=0) summary.nb(gal.county) Error in summary.nb(gal.county) : Not a neighbours list #end The gal file works just fine in GeoDa (also up to date).
2003 Jul 01
0
RE: question about spatial correlation with Xs and Ys
-----Original Message----- From: r-help-request at stat.math.ethz.ch [mailto:r-help-request at stat.math.ethz.ch] Sent: Tuesday, July 01, 2003 3:09 AM To: r-help at stat.math.ethz.ch Subject: R-help Digest, Vol 5, Issue 1 At 18:48 30/06/2003, Martin Wegmann wrote: >hello, > >I want to do a test for spatial correlation. >I tried it with geary.test() but I don't understand the
2004 Feb 25
0
k nearest neighbours between two matrix
I have two dataframes A and B consisting of latitude longitude coordinates of points. For each point in A I want to find the k-nearest neighbours in B. Currently, I calculate the distance from each point in A to all the points in B (using rdist.earth() in fields package), sort the points of B by distance and select the k nearest ones. Is there a more efficient way to do this? Function knearneigh
2004 Aug 19
3
Do you know if you can map a large minimum spanning tree in R?
Thanks Mike. My data has longitude and latitude coords and I used distAB {clim.pact} then mst {ape} to calculate my minimum spanning tree. The nodes are telecoms sites from all over Australia. My goal is to determine the minimum cost of linking them via cabling, and I'm starting by calculating the distance "as the crow flies", but will probably eventually need to calculate the
2012 Jul 24
1
unable to run spatial lag and error models on large data
Hi: First my apologies for cross-posting. A few days back I posted my queries ar R-sig-geo but did not get any response. Hence this post. I am working on two parcel-level housing dataset to estimate the impact of various variables on home sale prices. I created the spatial weight metrics in ArcGIS 10 using sale year of four nearest houses to assign weights.  Next, I ran LM tests and then ran
2005 Jan 30
1
New user...tips for spdep?
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