Displaying 20 results from an estimated 30000 matches similar to: "Model selection and model efficiency - Search for opinions"
2013 Oct 28
3
speed of makeCluster (package parallel)
Hi all,
I am quite new in the world of parallelization and I wonder if there is a
way to increase the speed of creation of a parallel socket cluster. The
time spend to include threads increase exponentially with the number of
thread considered and I use of computer with two 8 cores CPU and thus
showing a total of 32 threads in windows 7.
Currently, I use the default parameters (type =
2011 Jun 14
2
Still have problems with tcltk in R 64 bit
Dear R users,
Since a long time now, I have the following error when I want to load
the tcltk library in R 64 bit.
Loading Tcl/Tk interface ...Error : .onLoad failed in loadNamespace()
for 'tcltk', details:
call: inDL(x, as.logical(local), as.logical(now), ...)
error: unable to load shared object 'C:/Program
Files/R/R-2.13.0/library/tcltk/libs/x64/tcltk.dll':
LoadLibrary
2012 May 01
2
Define lower-upper bound for parameters in Optim using Nelder-Mead method
Dear UseRs,
Is there a way to define the lower-upper bounds for parameters fitted by
optim using the Nelder-Mead method ?
Thanks,
Arnaud
[[alternative HTML version deleted]]
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
2012 Jul 06
1
Definition of AIC (Akaike information criterion) for normal error models
Dear R users (r-help@r-project.org),
The definition of AIC (Akaike information criterion)
for normal error models has just been changed.
Please refer to the paper below on this matter. Eq.(22) is
the new definition. The essential part is RSS(n+q+1)/(n-q-3);
it is close to GCV. The paper is temporarily available at
the "Papers In Press" place.
Kunio Takezawa(2012): A Revision of
2011 Mar 04
1
Problem with tcltk
Dear all,
Since I installed the x64 version of R (v2.12.1), I got a problem with tcltk
that I did not achieve to resolve.
When loading the library, it gives me the following error message:
Loading Tcl/Tk interface ...Error : .onLoad failed in loadNamespace() for
'tcltk', details:
call: inDL(x, as.logical(local), as.logical(now), ...)
error: unable to load shared object
2005 Sep 06
0
model selection vs. H0 based testing
> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch
> [mailto:r-help-bounces at stat.math.ethz.ch]On Behalf Of Thomas Petzoldt
> Sent: 06 September 2005 06:34
> Cc: petzoldt at rcs.urz.tu-dresden.de; R-Help
> Subject: Re: [R] model selection vs. H0 based testing
>
>
> Hello,
>
> I wish to thank Douglas Bates very much for clarification and
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
2013 May 21
1
Calculating AIC for the whole model in VAR
Hello!
I am using package "VAR".
I've fitted my model:
mymodel<-VAR(mydata,myp,type="const")
I can extract the Log Liklihood for THE WHOLE MODEL:
logLik(mymodel)
How could I calculate (other than manually) the corresponding Akaike
Information Criterion (AIC)?
I tried AIC - but it does not take mymodel:
AIC(mymodel)
# numeric(0)
Thank you!
--
Dimitri Liakhovitski
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
2017 Oct 20
3
nls() and loop
Hello I?m need fitt growth curve with data length-age. I want to evaluate
which is the function that best predicts my data, to do so I compare the
Akaikes of different models. I'm now need to evaluate if changing the
initial values changes the parameters and which do not allow to estimate
the model.
To do this I use the function nls(); and I randomize the initial values
(real positive number).
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
2012 Feb 03
1
GAM (mgcv) warning: matrix not positive definite
Dear list,
I fitted the same GAM model using directly the function gam(mgcv) ... then
as a parameter of another function that capture the warnings messages (see
below).
In the first case, there is no warning message printed, but in the last
one, the function find two warning messages stating "matrix not positive
definite"
So my question is: Do I have to worry about those warnings and
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
2012 Dec 13
1
Pairwise deletion in a linear regression and in a GLM ?
Dear useRs,
In a thesis, I found a mention of the use of pairwise deletion in linear
regression and GLM (binomial family).
The author said that he has used R to do the statistics, but I did not find
the option allowing pairwise deletion in both lm and glm functions. Is
there somewhere a package allowing that ?
Thanks,
Arnaud
[[alternative HTML version deleted]]
2012 Nov 14
1
GE LP Series?
Hi all
We have a 100kVA GE LP Series UPS. I can't find this series in the HCL, but other GE UPSes are listed. Would it be possible to somehow use NUT with this UPS?
--
Vennlige hilsener / Best regards
roy
--
Roy Sigurd Karlsbakk
(+47) 98013356
roy at karlsbakk.net
http://blogg.karlsbakk.net/
GPG Public key: http://karlsbakk.net/roysigurdkarlsbakk.pubkey.txt
--
I all pedagogikk er det
2005 Oct 24
1
Error in step() (or stepAIC) for Cox model
Hello all,
I am trying to use stepwise procedure to select covariates in Cox model
and use bootstrap to repeat stepwise selection, then record how many
times variables are chosen by step() in bootstrap replications. When I
use step() (or stepAIC) to do model selection, I got errors. Here is the
part of my code
for (j in 1:mm){ #<--mm=10
for (b in 1:nrow(reg.bs)){ #<--bootstrap 10
2016 Jun 20
2
Problems search using ldapusersearch + Samba4 (v4.4.4)
Good afternoon friends,
I am implementing squid + squidguard the pfsense authenticating samba 4
version 4.4.4
And always I get this message in squidguard logs.
2016-06-20 17:30:55 [75446] (squidGuard): ldap_simple_bind_s failed:
Strong(er) authentication required
2016-06-20 17:30:55 [75446] Added LDAP source: administrator
2016-06-20 17:30:55 [75446] (squidGuard): ldap_simple_bind_s failed:
2004 Jan 16
2
individual likelihoods
Dear all,
is there a way to extract individual likelihoods from a glm/lrm object?
By individual likelihoods, I mean the likelihoods whose product give the
overall likelihood of the model.
I guess the code in the base package, used to compute the Akaike Information
Criterion may help me.
However, I couldn't figure it out, probably because I'm rather new to
likelihood theory and ML
2012 May 02
1
calibration of Garch models to historical data
I have done the usual estimation of GARCH models, applied to my historical
dataset (commodities futures) with a maximum likelihood function and
selected the best model on the basis of information criteria such as Akaike
and Bayes.
Can somebody explain me please the calibration scheme for a GARCH model?
I was not able to find a paper, dealing with exactly this algorithm for my
case. I only