Displaying 20 results from an estimated 2000 matches similar to: "Using PCNM() in Vegan and calculating Moran's I"
2011 Sep 13
1
mvpart analyses with covariables
Hi all,
I am fairly new to R and I am trying to run mvpart and create a MRT using
explanatory variables and covariables. I've been following the procedures in
Numerical Ecoogy with R.
The command (no covariables) which works fine -
ABUNDTMRT <- mvpart(abundance ~
.,factors,margin=0.08,cp=0,xv="1se",xval=nrow(abundance),xvmult=100,which=4)
where abundance is 4th root
2007 Oct 26
1
Help needed on calculation of Moran's I
Hi,
I am trying to calculate Moran's I test for the residuals for a
regression equation, but I have trouble converting my coordinates into
nb format.
I have used the dnearneigh() funtion now with an arbitrarily high upper
distance to make it include all plots. However, when I do the
lm.morantest() I get a Moran's I value which is the same as the expected
value and a P-value of 1.
I
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
2003 Jun 06
2
Moran's index
Hi,
I am looking for some code for Moran's I. Has anyone previously done this?
I have been unable to find it in the search engines.
James
2008 Apr 18
1
spdep question - Moran's I
Dear all,
I would like to calculate a Moran's I statistic using the moran function in the spdep package. The problem I'm having deals with how to create the listw object.
My data stems from the area of social network analysis. I have list of poeple and for each pair of them I have a measure of their relationship strength. So my dataset looks like: Jim; Bob; 0.5
This measure of
2006 Oct 03
2
pdf/ convert/ font problem
Background:
OS: Linux Ubuntu Dapper
R : Version 2.3.1 (2006-06-01)
Emacs 21.4.1
ESS
Colleagues
This is neither a bug report, nor a complaint, so I think this is the
appropriate list.
I am getting an odd font problem with a pdf generated using
pdf(file =
"../figures/PCNM.models.larvae.fluor.zoo.stability.2001.and.2002.pdf",
title="", family="serif",
2006 Mar 24
1
who can tell me the reason why it is different on calculating Moran's I using ARCGIS, Geoda and R?
The attachment is my dataset:
1.ccc.shp (the original data)
2.ccc.gwt, which is computed by Geoda;
Introduction to the variables in my data:
ID: key variable;
N_LATITUDE: latitude measured by GPS;
E_LONGITUD: longitude measured by GPS;
LIVES: attribute data
I get the different result of Moran's between ARCGIS and Geoda, R, why?
ARCGIS:spatial statistics tools:spatial
2000 Jun 29
2
Local Moran's I / Getis and Ord and Rousseauw Cluster Algorithms
Sorry for the repetition, unless I've got bad deja vu this questions been
asked before but I couldn't turn up an answer on CRAN. Is there already
any code in existence for local dependence measures such as Moran's I or
Getis and Ord G?
Also, S-Plus has a number of interstingly named Cluster Algorithms based on
some previous stand-alone fortran algorithms (agnes, daisy etc.) which
2006 Mar 14
1
help on moran's I index of point pattern, not areal pattern
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
2003 Apr 14
1
How to do the significant test on Local Moran's I
Dear list:
I've tried professor Roger Bivand's spdep package
for a while, and found it is quite useful. However,
when considering the significance test of the local
moran's index under the assumption of both normality
and randomization, I just can't get a clue from the
package's calculating results. I also read professor
Luc Anselin's 1995 LISA paper (geographical
2005 Mar 04
1
R: Moran's I
Hi-
I would like to assign distance classes (lags) to the moran''s I test in R.
I don¹t have equally spaced points since I was mapping shrubs across a
landscape (vs. an experiment or survey in a grid). I somehow need to
select points based on the distances in the distance matrix (i.e., I need to
select all pairs of points that occur 0-25 m from each other, 25-50 m,
etc...).
Does
2010 Sep 21
1
partial dbRDA or CCA with two distance objects in Vegan.
I am trying to use the cca/rda/capscale functions in vegan to analyse
genetic distance data ( provided as a dist object calculated using
dist.genpop in package adegenet) with geographic distance partialled out
( provided as a distance object using dist function in veganthis method
is attempting to follow the method used by Geffen et al 2004 as
suggested by Legendre and . FORTIN (2010).
I
2012 Jan 11
2
Vegan(ordistep) error: Error in if (aod[1, 5] <= Pin) { : missing value where TRUE/FALSE needed
I am getting the following erro rmessage in ordistep. I have a number of
similarly structured datasets using ordistep in a loop, and the message
only occurs for some of the datasets.
I cannot include a reproducible sample - the specific datasets where this
is occur ing are fairly large and there are several pcnm's in the rhs of
the formula.
thanks for any pointers that may allow me to
2010 Jun 21
0
how to find observed Moran's I value using moran.test(spdep)
Dear ,
This is Elaine.
I am computing moran's I using moran.test for
a generalized linear model (multiregression).
The following contents are the results, and I cannot find the observed
Moran's I mentioned as estimate in the manual.
Please kindly help indicate if there is observed Moran's I did not notice or
other method for calculation.
Thanks
Elaine
data: residuals(modg1)
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
2011 Jan 19
0
Error Moran's test : reconsider test arguments
Dear
R-users,
I was
wondering if someone could give me some advices on the following problem.
I tried to
apply moran’s test to a small dataset and couldn’t succeed, here is the error
message:
mor <- moran.test(x, res2)
Avis dans
moran.test(x, res2) :
Out-of-range p-value: reconsider test arguments
mor
Moran's I test under randomization
data: x
weights: res2
2008 Jul 14
0
Moran's I- Ordinal Logistic Regression
Hi,
I am trying to do a Moran's I test on an ordinal logistic regression model.
I have a simple spatial weights matrix listed below I would like to use.
Y=
1
0
0
0
0
0
0
0
0
0
1
1
0
0
0
0
1
1
0
1
1
0
0
0
0
1
1
0
0
0
1
1
1
1
0
0
0
0
0
1
1
1
1
0
0
0
0
0
1
1
1
1
0
0
0
0
0
1
1
1
1
0
0
0
1
1
0
0
0
0
1
1
0
0
1
0
0
0
0
1
1
I try to run the test as follows-
moran.test(order$resid,
2005 Mar 29
0
Plot Moran's I
Hello all,
I'm a new user of R and I have used the spdep package to calculate Moran's I estimates. I used the dnearneigh() function and moran.test() function and obtained what I wanted, but now I want to plot my results with the p-values. I regrouped my results for the Moran's I like
>m=c(m1$e,m2$e...) #m1 contain the results of the moran.test for lag1
2011 Aug 04
1
Running a column loop through the Moran.I function.
Dear R users,
I have two data frames that consist of statistical information for most
countries around the world. One dataframe consists of the latitude and
longitude ("coord.csv") of each country, while the other consists of 100's
of different attributes ("countryattri.csv") for each country (like, GDP,
Population, etc.). The data is organized with a header and then