Displaying 20 results from an estimated 8000 matches similar to: "multi-model inference"
2005 Oct 29
2
LaTex error when creating DVI version when compiling package
Dear Listers,
I got this message when compiling a package:
* creating pgirmess-manual.tex ... OK
* checking pgirmess-manual.text ... ERROR
LaTex errors when creating DVI version.
This typically indicates Rd problems.
The message is quite explicit but I struggled a lot before understanding
that the trouble comes from a single file "selMod.rd" among 44 topics.
Even though I have
2006 Feb 20
1
Nested AIC
Greetings,
I have recently come into some confusion over weather or not AIC
results for comparing among models requires that they be nested.
Reading Burnham & Anderson (2002) they are explicit that nested
models are not required, but other respected statisticians have
suggested that nesting is a pre-requisite for comparison. Could
anyone who feels strongly regarding either position
2003 Mar 04
1
Sample size and stepAIC, step, or AIC
Do any R functions incorporate a sample sample size correction (e.g.,
Burnham and Anderson 1998).
Thanks,
Hank Stevens
Martin Henry H. Stevens, Assistant Professor
338 Pearson Hall
Botany Department
Miami University
Oxford, OH 45056
Office: (513) 529-4206
Lab: (513) 529-4262
FAX: (513) 529-4243
http://www.cas.muohio.edu/botany/bot/henry.html
http://www.muohio.edu/ecology
2004 Mar 09
4
aic calculation
hello,
could somebody refer me to the reason R uses
-2*loglik + 2*(#param)+2
to calculate AIC?
thank you
--
Stoyan Iliev
2003 Apr 22
7
Subject: Eliminate repeated components from a vector
X-Mailer: VM 7.00 under 21.4 (patch 6) "Common Lisp" XEmacs Lucid
Reply-To: fjmolina at lbl.gov
FCC: /home/f/.xemacs/mail/sent
Does anyone know how I can eliminate repeated elements from a vector?
2005 Nov 03
1
Help on model selection using AICc
Hi,
I'm fitting poisson regression models to counts of birds in
1x1 km squares using several environmental variables as predictors.
I do this in a stepwise way, using the stepAIC function. However the
resulting models appear to be overparametrized, since too much
variables were included.
I would like to know if there is the possibility of fitting models
by steps but using the AICc
2005 Jul 03
1
code for model-averaging by Akaike weights
Dear all,
does anyone have r code to perform model-averaging of regression
parameters by Akaike weights,
and/or to do all-possible-subsets lm modelling that reports parameter
estimates, AICc and number of parameters for each model?
I have been looking for these in the archive but found none.
(I am aware that many of you would warn me against these methods
advocated by Burnham and Anderson
2008 Jun 21
1
stepAIC {MASS}
In a generalized linear model with k covariates, there are 2(kth power) - 1
possible models (excluding interactions).
Awhile ago a posting to R-help suggested Model Selection and Multimodel
Inference, 2nd ed, by Burnham and Anderson as a good source for
understanding model selection. They recommend (page 71) computing AIC
differences over all candidate models in the set of possible models.
After
2003 Jul 04
1
Quasi AIC
Dear all,
Using the quasibinomial and quasipoisson families results in no AIC being
calculated. However, a quasi AIC has actually been defined by Lebreton et al
(1992). In the (in my opinon, at least) very interesting book by Burnham and
Anderson (1998,2002) this QAIC (and also QAICc) is covered. Maybe this is something
that could be implemented in R.
Take a look at page 23 in this pdf:
2009 Feb 25
3
indexing model names for AICc table
hi folks,
I'm trying to build a table that contains information about a series of
General Linear Models in order to calculate Akaike weights and other
measures to compare all models in the series.
i have an issue with indexing models and extracting the information
(loglikehood, AIC's, etc.) that I need to compile them into the table.
Below is some sample code that illustrates my
2005 Jun 18
1
how 'stepAIC' selects?
> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch
> [mailto:r-help-bounces at stat.math.ethz.ch]On Behalf Of B??kony Veronika
> Sent: 18 June 2005 14:00
> To: r-help at stat.math.ethz.ch
> Subject: [R] how 'stepAIC' selects?
>
>
> Dear all,
> Could anyone please tell me how 'step' or 'stepAIC' works? Does it
>
2007 Mar 09
4
Reg. strings and numeric data in matrix.
Hi All,
Sorry for this basic question as I am new to this R. I would like to know,
is it possible to consider a matrix with some columns having numeric data
and some other's with characters (strings) data? How do I get this type of
data from a flat file.
Thanks very much,
mallika
____________________________________________________________________________
Mallika Veeramalai, Ph.D.,
2005 Aug 08
2
AIC model selection
Hello All;
I need to run a multiple regression analysis and use Akaike's Information
Criterion for model selection. I understand that this command will give the
AIC value for specified models:
AIC(object, ..., k = 2)
with "..." meaning any other optional models for which I would like AIC
values. But, how can I specify (in the place of "...") that I want R to
2008 Apr 20
1
Reg. consensus ranking
Dear All,
I have a list of models(1000) which have variable scores from 20 different method. I would like to rank models using consensus approach based on high scores from different methods.Is there any function available in R for this purpose? I will appreciate any pointers in this regard.
Thank you very much in Advance,
Mallika
2003 Sep 04
1
AIC and significance tests
Hi
I have two geostatistical models from geoR. An ordinary kriging model with
AIC=-148.6 and a universal kriging model with AIC=-156.7, there are 345
data points. The improvement shown by the AIC by adding a trend component
to the model seems quite small given the number of data points, is there a
test to see if the improvement to the model fit is significant?
Thanks
David
2001 Sep 13
2
akaike's information criterion
Hello all,
i hope you don't mind my off topic question. i want to use the Akaike criterion
for variable selection in a regression model. Does anyone know some basic
literature about that topic?
Especially I'm interested in answers to the following questions:
1. Has (and if so how has) the criterion to be modified, if i estimate the
transformations of the variables too?
2. How is the
2006 Jan 30
4
Logistic regression model selection with overdispersed/autocorrelated data
I am creating habitat selection models for caribou and other species with
data collected from GPS collars. In my current situation the radio-collars
recorded the locations of 30 caribou every 6 hours. I am then comparing
resources used at caribou locations to random locations using logistic
regression (standard habitat analysis).
The data is therefore highly autocorrelated and this causes Type
2008 Dec 19
4
Akaike weight in R
Odette
> Wondering how can I generate "Akaike weight" with R? I know the description,
> but is there any function to generate by R on the web-site or R library?
> I am using GLM or GLMM (family=binomial), so would be appreciated if you
> help me.
You could have a look at this.
http://bm2.genes.nig.ac.jp/RGM2/R_current/library/aod/man/summary.aic.html
Which is in the OAD
2011 Mar 24
3
How create vector that sums correct responses for multiple subjects?
I have a data file with indicates pretest scores for a linguistics
experiment. The data are in long form so for each of 33 subjects there are
400 rows, one for each item on the test, and there is a column called
‘Correct’ that shows ‘C’ for a correct response and ‘E’ for an incorrect
response. I am trying to write a formula that will create a vector that
indicates the number of correct answers
2010 Jul 05
2
Can anybody help me understand AIC and BIC and devise a new metric?
Hi all,
Could anybody please help me understand AIC and BIC and especially why do
they make sense?
Furthermore, I am trying to devise a new metric related to the model
selection in the financial asset management industry.
As you know the industry uses Sharpe Ratio as the main performance
benchmark, which is the annualized mean of returns divided by the annualized
standard deviation of returns.