Displaying 20 results from an estimated 200 matches similar to: "geoR : Passing arguments to "optim" when using "likfit""
2008 Jun 26
0
geoR : Passing arguments to "optim" when using "likfit"]
Mzabalazo Ngwenya wrote:
> Hi everyone !
>
> I'm am trying to fit a kriging model to a set of data. When I just run
> the "likfit" command I can obtain the results. However when I try to
> pass additional arguements to the optimization function "optim" I get
> errors. That is I want to obtain the hessian matrix so matrix
> (hessian=TRUE).
>
2008 Aug 15
1
Strange error message from geoR´s likfit () lik. max. func.
ComRades:
I am geeting the error message
Error in ldots[[which(MET)]] : attempt to select less than one element
when I try to fit the geostatistical model with the likfit() function of
geoR.
I have tried with old data for which likfit() successfully maximised the
likelihood in previous versions of geoR, and yet the current version
fails.
I have tried in Windows Vista and Windows XP (I haven't
2010 Aug 04
1
geoR - likfit failure
Hi
I'm using geoR package to perform linear spatial interpolation(OK).
The function likfit() fails to compute REML.
The error meassage is : Error in solve.default(v$varcov, xmat);
How I can find out that likfit() is failed to process and retrieving the error message ?
Thank you so much for your help.
2012 Nov 07
2
pseudo R-squared with likfit (geoR)
We want to compute a pseudo R-squared for a model whose parameter
estimation was based on maximum likelihood (function likfit, package geoR).
I tried to compute the R2 proposed by Maddala (1983) which compare the
maximized likelihood for the model without any predictor and the
maximized likelihood for the model with all predictors.
I got a really low value (0,01%). Did I miss something? Are
2007 Jul 24
0
geoR/likfit: variance explained by model
I have been modelling spatial data using function likfit in package geoR. Now that I have the spatial regression models, I would like to calculate the amount of variance explained by both the trend and the spatial parts of the model. Any advice on how to do this would be much appreciated.
Cheers,
Ailsa
2006 Jan 13
1
help with gepRglm::likfit.glsm
> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch [SMTP:r-help-bounces at stat.math.ethz.ch] On Behalf Of ernesto
> Sent: Friday, January 13, 2006 9:25 AM
> To: Mailing List R
> Subject: [R] help with gepRglm::likfit.glsm
>
> Hi,
>
> I'm exploring likfit.glsm and I need some help. I have to say that I'm
> not an MCMC expert ...
>
2007 Aug 20
0
Covariance of beta and lambda in geoR likfit
Greetings comRades:
Has anyone worked out a procedure to calculate the estimated covariance
between the beta and lambda estimates in the likelihood-based
geostatistical model implemented in package geoR? If so, please help me
out by letting me know.
Do I have reasons to expect that this covariance term would be big or
perhaps more happily, that it could be discarded without much effect?
2009 Jan 19
0
Trend.spatial function in geoR
I am having difficulty getting the trend.spatial function in geoR to
work properly. After creating a trend.spatial object with a covariate,
I try to add the command into my likfit() function as follows:
trend1.trend.spatial <- trend.spatial("1st", trend1.geodata)
trend1.spatial.EC0.1.reml <- likfit(spatial.geodata,
trend1.trend.spatial, ini.cov.pars = spatial.EC0.1.eyefit,
2012 Oct 04
1
geoRglm with factor variable as covariable
Dear R users.
I'm trying to fit a generalised linear spatial mode using the geoRglm
package. To do so, I'm preparing my data (geodata) as follow:
geoData9093 = as.geodata(data9093, coords.col= 17:18, data.col=15,*
covar.col=16*)
where covar.col is a factor variable (years in this case 90-91-92-93)).
Then I run the model as follow:
/
model.5 = list(cov.pars=c(1,1),
2004 Nov 18
0
implementing a "loop" using by(x,x$factor,FUN)
Hi,
I'm writing some R code that requires a massive amount of looping and would
ideally like to write it so that it avoid the use of "for" loop ... however I'm
having some trouble.
Very briefly, the basic idea is to implement a binary partitioning algorithm to
determine the optimal cutpoint based on deviance measures obtained from
likelihood estiamtes. This is in the
2011 Oct 28
0
problem with glsm.krige: trendd and trend l must have similar specifications error
Hello,
I used glsm.mcmc and likfit.glsm to create model. Now I want to predict at different locations, but I can't get glsm.krige to work. I keep getting the error that trend.d and trend.l must have similar specifications. I have tried numerous ways to include the covariates in the glsm.krige model, and I keep getting the same error message. The bolded part is the part that doesn't work.
2006 Jan 05
1
Memory limitation in GeoR - Windows or R?
Dear Aaron,
I am really a tool user and not a tool maker (actually an ecologist
doing some biostatistics)... so, I take the liberty of sending a copy of
this e-mail to the r-help list where capable computer persons and true
statisticians may provide more relevant information and also to Paulo
Ribeiro and Peter Diggle, the authors of geoR..
I really feel that your huge matrix cannot be
2006 Aug 30
1
Handling realisations in geoRglm
Dear R users:
I want to model mosquito count data based on landcover attributes and
meteorological variables using a Poisson GLSM in the geoRglm package. I
have monthly mosquito counts over more than 20 years with repeated
observations from individual trap sites over time. I have used
as.geodata() to successfully read my dataset into the geodata format
utilized by geoR and geoRglm,
2008 Aug 18
1
GeoR model.control - defining covariates at prediction locations
Hi,
Im using geoR and I'm trying to do some predictions, based on an external
trend.
I'm having some problems specifying my model.control, specifically how do I
define my model, and also the source of the covariate data at the prediction
locations?
I am assuming that the covariate data at the prediction locations should be
imported to a geodata object along with the prediction location
2004 Oct 05
1
Bug in optim - way to solve problem?
Hi,
I want to automatically fit variograms to a large number of different
sample data sets, and call the funtion "likfit" (in package geoR) from
within a for-loop. "likfit" does again call "optim". After ssuccessfully
fitting variograms to some of the data sets, the procedure crashes and I
get the error message:
Error in optim(par = ini, fn = negloglik.GRF,
2003 Sep 30
2
non-linear trends in kriging model
Hi
I am struggling to fit a non-linear trend using the
likfit function in geoR.
Specifically I want a sigmoidal function, something
like SSfpl in the nls package to fit the trend. But
it seems trend.spatial in geoR only works with lm or
glm type models.
Any ideas how I can specify the model to calculate the
kriging parameters using REML, including the
parameters of a sigmoidal trend function
2010 Nov 17
1
Please, help me with 'mattern' variogram
Hi, R-folks:
I have been tryin many combination of parameter to make Matern variogram to work, but I can't find the available one. I'm near to be crazy.
I tiped:
A?o2003Selg.lf<-likfit(A?o2003Selg,cov.model="matern",ini.cov.pars=c(1.5,14),kappa=2.5,fix.kappa=FALSE,nugget=0.08,lambda=0.008,fix.lambda=FALSE,hessian=TRUE)
the hessian shows:
$hessian
[,1]
2005 Dec 13
1
bug in geoR (?)
I've enconuntered this problem with the last cran version of geoR:
> library(geoR)
> day <- rep(1:2, each=5)
> coords <- matrix(rep(runif(10),2), 10, 2)
> data <- rnorm(10)
> data[1] <- NA
> as.geodata(cbind(coords, data, day), realisations=4)
as.geodata: 1 points removed due to NA in the data
Errore in as.geodata(cbind(coords, data, day), realisations = 4) :
2003 Mar 25
1
geoR vector length error
Dear,
we have a problem with geoR. We try to read an ASCII table (x,y,z) with 40000
lines. With read.geodata we get the error:
Error in vector("double", length) : cannot allocate vector of length 799980000
We can read the file without any problem with read.table, but trying to
convert it to the geodata class gets the same error.
Any help/tips would be appreciated.
Kris, Dave
--
2003 Feb 11
2
geoR question from new R user
Hi,
I'm a new R user. My goal is to do a variogram using geoR.
I started by trying to do the example in the geoR Illustrative Session
using my own data.
I am able to read in my Ascii data using: D <- matrix(scan("file.dat",
n=530*3), 530,3, byrow=TRUE).
Then I use: as.geodata(D, coords.col=1:2, data.col=3) to make the
object D geodata.
I check the descriptive statistics,