Displaying 20 results from an estimated 1000 matches similar to: "R's AIC values differ from published values"
2012 Sep 13
1
AICcmodavg
I am using the AICmodavg package and using R version 2.15.1. I need help
with code that is instead being read as text.
Below is a subset of code... I actually have 12 models, but I am trying to
get this to work for 2 below right now.
Everything 'appears' to work through the line starting with Modnames. After
that the code starting with aictab and beyond is recognized as text and not
2010 Dec 14
2
How to bind models into a list of models?
Hi R-helpers,
I have a character object called dd that has 32 elements each of which
is a model formula contained within quotation marks. Here's what it
looks like:
> dd
[1] "lm(y ~ 1,data=Cement)" "lm(y ~
X,data=Cement)" "lm(y ~ X1,data=Cement)"
[4] "lm(y ~ X2,data=Cement)" "lm(y ~
2018 Feb 20
1
question regarding the AICcmodavg package
Dear moderator,
If possible I would like to send in the following question for R-help:
I am analyzing a small data set using PGLS with phylogenetic uncertainty
taken into account and thereby including 100 potential phylogenetic tree
scenarios. I've managed to run models on all of the different trees and
performed model averaging to get parameter estimates for the intercept and
most of the
2010 Aug 17
2
how to selection model by BIC
Hi All:
the package "MuMIn" can be used to select the model based on AIC or AICc.
The code is as follows:
data(Cement)
lm1 <- lm(y ~ ., data = Cement)
dd <- dredge(lm1,rank="AIC")
print(dd)
If I want to select the model by BIC, what code do I need to use? And when
to select the best model based on AIC, what the differences between the
function "dredge" in
2012 Jan 17
1
MuMIn package, problem using model selection table from manually created list of models
The subject says it all really.
Question 1.
Here is some code created to illustrate my problem, can anyone spot where I'm going wrong?
Question 2.
The reason I'm following a manual specification of models relates to the fact that in reality I am using mgcv::gam, and I'm not aware that dredge is able to separate individual smooth terms out of say s(a,b). Hence an additional request,
2011 Jul 13
3
Sum weights of independent variables across models (AIC)
Hello,
I'd like to sum the weights of each independent variable across linear
models that have been evaluated using AIC.
For example:
> library(MuMIn)
> data(Cement)
> lm1 <- lm(y ~ ., data = Cement)
> dd <- dredge(lm1, beta = TRUE, eval = TRUE, rank = "AICc")
> get.models(dd, subset = delta <4)
There are 5 models with a Delta AIC Score of
2010 Aug 17
2
AIC in MuMIn
Hello,
I am using package MuMIn to calculate AIC for a full model with 10
explanatory variables.
Thanks in advance in sharing your experience.
Q1
In the AIC list of all models, each model is differentiated by model number.
Please kindly advise if it is possible to
find the corresponding explanatory variable(s) for the model number.
Q2 error message
I tried to display sub-model with only
2010 Oct 18
1
Basic structure operations doubt
I'm doing these manipulations on the data frame and wondering why does R
have to remember historical data on my operation and not just keep the
needed info.
Probably a basic fundamentals of the way R handles data .. Pls point me to
the manual if possible ..
I have this Index data:
> head(NIFTY_INDX)
Constituents.list.of.S.P.CNX.Nifty X X.1
X.2 X.3
2006 Jun 14
3
appending
All,
In the function below I have 24 individuals and 6 calculations per
individual.
The 6 calculations are collected each time in a 1:24 loop when
calculating "delta".
I'd like to collect all 144 = 24*6 calculations in one vector
("delta.patient.comb").
The function works as is via indexing, but is there an easier way to
collect the measurements via appendinng the 6
2008 Nov 26
1
Creating a vector based on lookup function
I am still searching for a solution to what i think is a simple problem i am
having with building a vector in a for loop. I have built a more
understandable example so hopefully that will help..help you, help me, if
you know what i mean.
dev=400
#test location model TAZs to reference
cands=c(101,105,109)
#Create Object of length of cands
candslength=length(cands)
#TEST TAZ Vector
2010 Aug 10
2
question about bayesian model selection for quantile regression
Hi All:
Recently I am researching my dissertation about the quantile model selection
by bayesian approach. I have the dependent variable(return) and 16
independent variables and I need to select the best variable for each
quantile of return. And the method I used is the bayesian approach, which is
based on calculating the posterior distibution of model identifier. In other
words, I need to obtain
2010 Sep 16
2
glm: formula vs character
Hello,
This is a question motivated by curiosity, not a pressing problem. Any
responses are much appreciated! In the following code, function reg1 calls
glm with a formula object while reg2 uses a string. In both cases, glm
works; however, in the second case, the add1 function fails with the
following message: "Error in eval(predvars, data, env) : invalid 'envir'
argument."
2003 Mar 13
1
small error in regression tests
I just r-sync'ed the r-devel version of R-1.7.0 (2003-03-11), compiled it
under RH-8.0 and ran make check. The reg-tests-2 fails at the very end
with the message stating that "object cement was not found". It looks like
this piece of the regression test is new to version 1.7. The the piece of
code generating the error is:
if(require(MASS)) {
teststep <- function(formula,
2003 Mar 13
1
small error in regression tests
I just r-sync'ed the r-devel version of R-1.7.0 (2003-03-11), compiled it
under RH-8.0 and ran make check. The reg-tests-2 fails at the very end
with the message stating that "object cement was not found". It looks like
this piece of the regression test is new to version 1.7. The the piece of
code generating the error is:
if(require(MASS)) {
teststep <- function(formula,
2008 Nov 07
2
Problem building kernel (gpg problem) - 2.6.18-92.1.17
With new kernel, appeared some problems with build proccess here.
After many minutes waiting for rpmbuild were over, a gpg problem appears!!:
...
scripts/modsign/mod-extract.c:311: warning: format '%lx' expects type
'long unsigned int', but argument 3 has type 'Elf64_Xword'
+ KEYFLAGS='--no-default-keyring --homedir ..'
+ KEYFLAGS='--no-default-keyring
2017 Nov 23
3
mischeduler (pre-RA) experiments
Hi,
I have been experimenting for a while with tryCandidate() method of the
pre-RA mischeduler. I have by chance found some parameters that give
quite good results on benchmarks on SystemZ (on average 1% improvement,
some improvements of several percent and very little regressions).
Basically, I add a "latency heuristic boost" just above processor
resources checking:
2010 Oct 12
1
delta AIC for models with 2 variables using MuMIn
Dear List,
I want to ask a AIC question based on package library(MuMIn)
The relative importance of 16 explanatory variables
are assessed using delta AIC in a generalized linear model.
Please kindly advise if it is possible to show models
with any two only certain variables.
Thank you.
Elaine
I asked a similar question and got a great help for models
with only one variable as below.
2001 Dec 20
2
RH7.2&&smbd2.2.1a&&W98/2000&&Connection Problem
Hello all!
I've readed somes docs and I found nothing about the
following trouble : I can't connect to my sbmd server using
the following : '\\MYRH72SMBDSERVERNAME\'. I always got
a error message like : 'Share name could not be found, make
sure you typed it correctly....' , but if I utilize \\10.x.x.x\ all is
working fine (I don't want to access using the \\IP\
2006 Mar 30
1
Predict function for 'newdata' of different dimension in svm
I am using the "predict" function on a support vector machine (svm)
object, and I don't understand why I can't predict on a dataset with more
observations than the training dataset.
I think this problem is a generic "predict" problem, but I'm not sure.
The original svm was fit on 50 observations.
2009 Dec 09
1
partial match for two datasets
Hi all,
I have two sets:
dig<-c("DAVID ADAMS","PIERS AKERMAN","SHERYLE BAGWELL","JULIAN BAJKOWSKI","CANDIDA BAKER")
import<-c("by DAVID ADAMS","piersAKERMAN","SHERYLE BagWEL","JULIAN BAJKOWSKI with ","Cand BAKER","smith green")
I want to get the following result from