Displaying 20 results from an estimated 1000 matches similar to: "autologistic modelling in R"
2004 Apr 16
0
autologistic regression with Gibbs sampler
Hello everyone,
I have some binary, spatially autocorrelated data I would like to run autologistic regression on. I hope to incorporate both ordinary covariates (environmental predictors) and a spatial autocovariate in the model, ideally with a second-order neighbourhood structure. Since my computing skills are limited, I am wondering if anyone has composed an algorithm for this purpose, and
2006 Sep 30
1
autologistic model? - what package?
Dear all,
Could you pleas advise me on the following?
I need to use general(ized) linear models (binomial distribution + logit
link function) , to describe the preferred environment of each species (each
sample is an individual in which I have measured several variables and also
recorded the species it belongs to)
However, must account for the spatial autrefoocorrelation between
2017 Nov 15
1
Autologistic regression in R
Hi,
I am new to autologistic regression and R. I do have questions when starting a project in which I believe autologistic regression is needed.
I have a point layer whose attribute table stores the values of the dependent variable and all the independent variables. I hope to to fit an autologistic model to analyze which factors or combinations of factors have effects on the presence/absence of
2001 Aug 08
1
Package for variable clustering
Dear R users:
is there a package, similar to varclus in SAS or varclus in S, ported or
written for R? Also, is there any other package in R that was designed
for
grouping the variables under different measures of distance (in cases
where data is non-Gaussian, autocorrelated, and so on).
Janusz.
--
** Janusz Kawczak **
** UNC at Charlotte,
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
2009 Aug 25
1
Autocorrelation and t-tests
Hi,
I have two sets of data for a given set of (non-lattice) locations. I would
like to know whether the two are significantly different. This would be
simple enough if it wasn't for the fact that the data is spatially
autocorrelated. I have come across several possible solutions (including
Cliff & Ord which however appears to be for gridded data), or using gls.
However, they don't
2013 Feb 02
1
repeating autocovariate functions
Hi there,
Just wondering why my post was rejected?
cheersRachel
Subject: repeating autocovariate functions
From: r-help-owner@r-project.org
To: moyble@hotmail.com
Date: Sat, 2 Feb 2013 02:56:27 +0100
Message rejected by filter rule match
--Forwarded Message Attachment--
Date: Fri, 1 Feb 2013 17:56:14 -0800
From: moyble@hotmail.com
To: r-help@r-project.org
Subject: repeating autocovariate
2006 Oct 03
1
loaded or not?
Dear all,
Sorry for such basic question, but. when R "says":
library(Rcitrus)
Loading required package: geoR
Loading required package: sp
-------------------------------------------------------------
Analysis of geostatistical data
For an Introduction to geoR go to http://www.est.ufpr.br/geoR
geoR version 1.6-8 (built on 2006/06/29) is now loaded
2008 Sep 04
1
restricted bootstrap
Hello List,
I am not sure that I have the correct terminology here (restricted
bootstrap) which may be hampering my archive searches. I have quite a large
spatially autocorrelated data set. I have xy coordinates and the
corresponding pairwise distance matrix (metres) for each row. I would like
to randomly sample some number of rows but restricting samples such that the
distance between them is
2010 Apr 17
2
interpreting acf plot
Hello,
I am attending a course in Computational Statistics at ETH and in one of the assignments I am asked to prove that a time series is not autocorrelated using the R function "acf".
I tried out the acf function with the given data, according to what I found here: http://landshape.org/enm/options-for-acf-in-r/ this test data does not look IID but rather shows some trends so how can I
2010 Feb 12
1
nlme w/no groups and spatially correlated residuals
Hi,
I would like to specify a spherical correlation structure for spatially
autocorrelated residuals in a model based upon the logistic function of a
response that is a proportion (0 to 1) (so usual binary logistic regression
is not an option). There is no need for a g-side random effect with
grouping in this model. Am I correct that nlme requires this (meaning a
correlated error structure only
2012 Sep 27
2
Generating an autocorrelated binary variable
Hi R-fellows,
I am trying to simulate a multivariate correlated sample via the Gaussian copula method. One variable is a binary variable, that should be autocorrelated. The autocorrelation should be rho = 0.2. Furthermore, the overall probability to get either outcome of the binary variable should be 0.5.
Below you can see the R code (I use for simplicity a diagonal matrix in rmvnorm even if it
2008 Mar 20
5
time series regression
Hi Everyone,
I am trying to do a time series regression using the lm function. However,
according to the durbin watson test the errors are autocorrelated. And then
I tried to use the gls function to accomodate for the autocorrelated errors.
My question is how do I know what ARMA process (order) to use in the gls
function? Or is there any other way to do the time series regression in R? I
highly
2007 Nov 27
1
Difference between AIC in GLM and GLS - not an R question
Hi,
I have fitted a model using a glm() approach and using a gls() approach
(but without correcting for spatially autocorrelated errors). I have
noticed that although these models are the same (as they should be), the
AIC value differs between glm() and gls(). Can anyone tell me why they
differ?
Thanks,
Geertje
~~~~
Geertje van der Heijden
PhD student
Tropical Ecology
School of Geography
2007 Mar 13
1
AR(1) and gls
Hi there,
I am using gls from the nlme library to fit an AR(1) regression model.
I am wondering if (and how) I can separate the auto-correlated and random
components of the residuals? Id like to be able to plot the fitted values +
the autocorrelated error (i.e. phi * resid(t-1)), to compare with the
observed values.
I am also wondering how I might go about calculating confidence (or
2008 Jul 27
1
help with durbin.watson
Hi,
I have two time series, y and x. Diff(y) and Diff(x) both show no
autocorrelation. But durbin.watson(lm(Diff(y)~lag(Diff(x),k=-4)) gives a DW
value of zero. How come the residule is autocorrelated while Diff(y) and
Diff(x) are not? Does anyone know if in my case a DW of zero indicates
serial correlation, or is it telling me that the DW statistics is not the
appropriate statistics to use here?
2009 Aug 24
6
CRAN (and crantastic) updates this week
CRAN (and crantastic) updates this week
New packages
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Updated packages
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New reviews
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This email provided as a service for the R community by
http://crantastic.org.
Like it? Hate it? Please let us know: cranatic at gmail.com.
2005 Dec 29
3
importing shapefiles into spatstat
Dear R users,
I am using spatstat to analyze point patterns (tree locations). I would
like to import the shapefile with the study area polygons (six total) into R
and use it to create the window for the spatstat analysis. I do not simply
want to use a rectangle because the study areas spread out over 40000 ha.
Any suggestions would be greatly appreciated.
Thanks,
Charlotte Reemts
Charlotte
2009 Jan 07
1
troubles performing Moran.I test
dear R users,
I have troubles performing Moran.I test as suggested on
http://www.ats.ucla.edu/stat/r/faq/morans_i.htm
my spatial data are longitude and lattitide of communities. The
calculation of the inverse distance matrix according to the homepage
(using my data)
datAL <- read.csv2("C:\\Konvergenz AL.csv", header=T)
ALdist <- as.matrix(dist(cbind(datAL$L?nge,
2012 May 30
3
alternative generator for normal distributed variables
Hello,
currently I'm working on a model based on Monte-Carlo-Simulations.
I observed that a generated normal distributed times series using
rnorm(100,mean=0,sd=1)
is far away from being not autocorrelated.
Is there any other gerenator implemented in R, which might solve my problem?
--
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