Displaying 20 results from an estimated 10000 matches similar to: "Warning: Spatial weights matrix not row standardized"
2003 Jul 31
1
spatial statistics vs. spatial econometrics
Dear R users,
I am putting together reading and resources lists for spatial statistics and spatial econometrics and am looking for some pointers from more experienced practitioners.
In particular, I find two "camps" in spatial modelling, and am wondering which approach is better suitied to which situation.
The first camp is along the lines of Venables and Ripley's Chapter 14
2007 May 14
1
a question about spatial autocorrelation in R
Dear all,
I am currently facing a problem related to the spatial autocorrelation of
a sample of stations; these stations supply weekly data for a fixed
time-window during the year (namely, 4-6 months per year).
For this reason I'm trying to use the R package 'spdep' (specifically
Moran's I) in order to get rid of it.
Does anyone know how is it possible (if it is...) to
2003 Nov 14
1
spatial modeling
I am new to R and have a question about spatial econometrics. I have
noticed that you can easily test for spatial autocorrelation with the
spdep package, but was wondering if any code has been written to correct
for spatial autocorrelation? Or if there is any literature on this?
Thanks. -Jill
***************************************************
Jill L. Caviglia-Harris, Ph.D.
Assistant
2004 Apr 26
2
Spatial Autocorrelation for point data
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
2004 Aug 25
1
Newbie Question: Spatial Autocorrelation with R Tutorial?
Howdy All,
I am looking for some good tutorials (books, websites, whatever) for calculating/testing for Spatial Autocorrelation using R.
Specifically, I am wanting to test for autocorrelation of a number of variables measured at a set of discrete locations.
Up to this point I have been exploring the "spdep" package and I can get "moran.test" to work, but I am concerned that
2002 Sep 11
1
Question about spatial statistics
I?m tryng to use the SPDEP package in my research in the field of
population genetics. My data set
has the following format:
- x and y : coordinates,
- Z: allelic frequency in each loci (in a total of 8 locis) - this
variable can assume the values 0 ; 0.5 or 1.
The objective is to verify if there is a possible spatial
autocorrelation structure of the allelic frequency in a population of
2009 Nov 05
0
analysing HTS assay plates for spatial effects
Hi, I'm have some data on a grid (specifically high throughput assay plates)
and am interested 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,
2005 Apr 25
1
multiple autocorrelation coefficients in spdep?
Hello,
Has anyone modified the errorsarlm in the R package spdep to
allow for more than a single spatial autocorrelation coefficient (i.e.
'lambda')?
Or, if not, any initial suggestions on how to make that
modification? I have looked at the source code for the function and realize
that any attempt to do it on my own would require much dedication, so would
like to
2007 Oct 22
3
Spatial autocorrelation
Hi,
I have collected data on trees from 5 forest plots located within the
same landscape. Data within the plots are spatially autocorrelated
(calculated using Moran's I). I would like to do a ANCOVA type of
analysis combining these five plots, but the assumption that there is no
autocorrelation in the residuals is obviously violated. Does anyone have
any ideas how to incorporate these spatial
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
2009 Aug 24
1
lme, lmer, gls, and spatial autocorrelation
Hello folks,
I have some data where spatial autocorrelation seems to be a serious
problem, and I'm unclear on how to deal with it in R. I've tried to do my
homework - read through 'The R Book,' use the online help in R, search the
internet, etc. - and I still have some unanswered questions. I'd greatly
appreciate any help you could offer. The super-super short explanation is
2004 Aug 04
2
which package for spatial autocorr.
hello
which package do you recommend for spatial autocorrelation ?
regards
Ahmet Temiz
______________________________________
Inflex - installed on mailserver for domain @deprem.gov.tr
Queries to: postmaster at deprem.gov.tr
______________________________________
The views and opinions expressed in this e-mail message are ...{{dropped}}
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
2009 Oct 06
1
Spatial Autocorrelation
Hello,
I have a matrix with the distances among sites. And I have another matrix
with the presence and absence of each species in each site. I would like to
test the spatial autocorrelation among sites.
I have tried to use the function gearymoran of the ade4 package, but error
messages keep popping up. Do you know any function for me to test the
spatial autocorrelation of my data?
Thanks,
2009 Aug 17
0
Question spdep package - Moran's I
Dear all,
I have a question regarding the spdep package:
Assume that each person within my dataset is characterized by a continuous variable y. In order to test for spatial autocorrelation in y I calculated a Moran's I statistic. The problem is that y is also likely to be influenced by a series of other variables x that are unique to each person in my dataset. To test to which extent the
2007 Feb 06
2
How to do "moran's I test"?
I want to do "moran's I test" in R language. I try to use "gearymoran" in
Package "ade4","moran" in Package "spdep", and Moran.I in Package "ape". But
I do not know how to do it because data format is different.
My data:
x y dbh
111.03 10.7 7
118.11 0.28 1.2
165.36 0.36 8.4
2010 Apr 21
1
Creating artificial environmental landscape with spatial autocorrelation
Dear all:
Does anyone have any suggestions on how to make a spatially explicit landscape with spatial autocorrelation in R? In other words, a landscape where all cells have a spatial reference, and the environment values that are closer in space are more similar (positive spatial autocorrelation).
Thank you,
Laura
2010 Aug 02
1
removing spatial auto correlation
Hi list,
I am trying to fit arima model for a grid of 360x161x338 points,
where 360x161 is the spatial dimension and 338 is the number of time steps I
have, which is seasonal. For this purpose I used the auto.arima function in
forecast package. After fitting residuals at each grid in space, the auto
correlations are still significant ( but < 0.2). This make me think that the
data
2012 May 29
1
GLMMPQL spatial autocorrelation
Dear all,
I am experiencing problems using the glmmPQL function in the MASS package
(Venables & Ripley 2002) to model binomial data with spatial
autocorrelation.
My question - is the presence of birds affected by various hydrological
parameters?
Presence/absence data were collected from 83 sites and coupled against
hydrological data from the same site. The bird survey sampling effort
2009 Feb 08
1
Help on computing Geary's C statistic to test for Spatial Autocorrelation
Dear Users:
I have been trying to use the geary.test() function in *R*, but am having
slight difficulty understanding how I am to apply it in my context.
I have 2 matrices:
1) *n x p* matrix of *n* observations with *p* measurements each. It may be
noted that this matrix has a spatial dimension to it, as the
*n*observations are at different geographical locations on a map.
2) *n x n* spatial