Displaying 20 results from an estimated 4000 matches similar to: "Handle lot of variables - Regression"
2011 Oct 06
3
Wide to long form conversion
I have some data 'myData' in wide form (attached at the end), and
would like to convert it to long form. I wish to have five variables
in the result:
1) Subj: factor
2) Group: between-subjects factor (2 levels: s / w)
3) Reference: within-subject factor (2 levels: Me / She)
4) F: within-subject factor (2 levels: F1 / F2)
5) J: within-subject factor (2 levels: J1 / J2)
As this is the
2011 Sep 21
3
Reading data in lisp format
Hi, 
 I am trying to read the "credit.lisp" file of the Japanese credit database in UCI repository, but it is in lisp format which I do not know how to read.  I  have not found how to do that in the foreign library
http://archive.ics.uci.edu/ml/datasets/Japanese+Credit+Screening <http://archive.ics.uci.edu/ml/datasets/Japanese+Credit+Screening>  
Could anyone help me?
Best
2007 Nov 15
2
make config update-rc.d
On Debian the Asterisk Makefile does
/usr/sbin/update-rc.d asterisk start 10 2 3 4 5 . stop 91 2 3 4 5 .;
which results in a /etc/rc2.d/S10asterisk being written.
I think S10 is too early.
bind9 : S15
mysql : S19
zaptel: S20
ntp   : S23
What bothers me most is that mysql is not up when asterisk
starts. That's a bad thing if there are #execs in your config
files and if the scripts rely on
2005 Dec 08
1
mle.stepwise versus step/stepAIC
Hello,
I have a question pertaining to the stepwise regression which I am trying to 
perform.  I have a data set in which I have 14 predictor variables 
accompanying my response variable.  I am not sure what the difference is 
between the function "mle.stepwise" found in the wle package and the 
functions "step" or "stepAIC"?  When would one use
2003 Jun 20
2
stepwise regression
Hi,
S-PLUS includes the function "stepwise" which can use a variety of
methods to conduct stepwise multiple linear regression on a set of
predictors.  Does a similar function exist in R?  I'm having difficulty
finding one.  If there is one it must be under a different name because
I get an error message when I try 'help(stepwise)' in R.
Thanks for your help,
Andy Taylor
2009 Oct 22
4
Bayesian regression stepwise function?
Hi everyone,
I am wondering if there exists a stepwise regression function for the
Bayesian regression model.  I tried googling, but I couldn't find anything. 
I know "step" function exists for regular stepwise regression, but nothing
for Bayes.
Thanks
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2012 Nov 15
1
Stepwise regression scope: all interacting terms (.^2)
Dear Gurus,
Thank you in advance for your assistance. I'm trying to understand scope better when performing stepwise regression using "step." I have a model with a binary response variable and 10 predictor variables. When I perform stepwise regression I define scope=.^2 to allow interactions between all terms. But I am missing something. When I perform stepwise regression (both
2006 Apr 28
4
stepwise regression
Dear all,
I have encountered a problem when perform stepwise regression. 
The dataset have more 9 independent variables, but 7 observation.
In R, before performing stepwise, a lm object should be given.
fm <- lm(y ~ X1 + X2 + X3 + X11 + X22 + X33 + X12 + X13 + X23)
However, summary(fm) will give: 
Residual standard error: NaN on 0 degrees of freedom
Multiple R-Squared:     1,      Adjusted
2012 Feb 17
3
stepwise selection for conditional logistic regression
 Hi,
Is there any function available to do stepwise selection of variables in Conditional(matched) logistic regression( clogit)? step, stepwise  etc are failing in case of conditional logistic regression. Please help. 
Thanks
P.T. Subha
	[[alternative HTML version deleted]]
2012 Nov 19
9
Stepwise analysis with fixed variables
Hello, 
How can I run a backward stepwise regression with part of the variables
fixed, while the others participate in the backward stepwise analysis? 
Thank you, Einat 
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2011 May 25
2
stepwise selection cox model
Sorry, I have wrote a wrong subject in the first email!
Regards,
Linda
---------- Forwarded message ----------
From: linda Porz <linda.porz@gmail.com>
Date: 2011/5/25
Subject: combined odds ratio
To: r-help@r-project.org
Cc: r-help-request@stat.math.ethz.ch
Dear all,
I am looking for an R function which does stepwise selection cox model in r
(delta chisq likelihood ratio test) similar
1999 Jun 18
1
Stepwise model selection question
I use the step() function occasionally, and I think I understand its
objective, proper use, and limitations.  Now I see stepwise model selection
being used in what seems to be an unusual way, and I wonder if it is right
or wrong.  May I describe?
     Genetic mapping tries to find where in an animal's genome are genetic
elements that influence a particular physical trait.  Say there are 100
2008 Sep 26
1
Tolerance levels in stepwise regression
Hello,
I have been using the step() function for stepwise regression and was
wondering if there was a way to specify a tolerance level either using
step() or another stepwise function.  So far I have only found an option to
specify tolerance in lm.fit() but I am not an experienced R user and am not
quite sure if this command can be implemented using a stepwise function.  I
have tried simply
2003 Jun 20
1
[OFF] stepwise using REML???
Hi,
I know that is not possible make a stepwise procedure using REML in R, I can 
use ML for this.
For nested design it may be very dangerous due the difference in variance 
structure, mainly in a splitplot design. ML make significative variables that 
REML dont make.
I read an article that is made a stepwise procedure using GENSTAT.
from article:
"Terms were dropped from a model in a
2011 Nov 04
2
Select some, but not all, variables stepwise
Hi,
I would like to fit a linear model where some but not all explanators are chosen stepwise - ie I definitely want to include some terms, but others only if they are deemed significant (by AIC or whatever other approach is available).  For example if I wanted to definitely include x1 and x2, but only include z1 and z2 if they are significant, something like this:
df <-
2008 May 09
2
Stepwise regression
I am using stepAIC for stepwise regression modeling. 
Is there a way to change the entry and exit alpha levels for the
stepwise regression using stepAIC ?
Many thanks,
Berthold 
Berthold Stegemann
Bakken Research Center
Maastricht
The Netherlands
	[[alternative HTML version deleted]]
2006 Dec 14
3
Stepwise regression
Dear all, 
I am wondering why the step() procedure in R has the description 'Select a 
formula-based model by AIC'. 
I have been using Stata and SPSS and neither package made any reference to 
AIC in its stepwise procedure, and I read from an earlier R-Help post that 
step() is really the 'usual' way for doing stepwise (R Help post from Prof 
Ripley, Fri, 2 Apr 1999 05:06:03
2011 Apr 13
1
strategy for writing out file with lines header initiated with comment sign
Dear all,
I have data.frame object in R. I want to export it in tab-delimited
file with several lines of header initiated with comment sign (#). I
do not know how to do that in R. Could you please give helps on this
problem?
Thanks in advance.
Best,
Jian-Feng,
##################################################################
The lines I want to write in the header lines look like, with words
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
2006 Apr 11
2
variable selection when categorical variables are available
Dear All,
Probably it is not highly relevant question: Why do stepwise regression
functions in R (step() or stepAIC()) add/delete categorical variables as a
set? For example, I have a four-level factor variable d, so dummies are
d1,d2,d3, as stepwise regression operates d, adding or removing, d1,d2,d3
are simultaneously added/removed. What's the concern here if operating
dummies individually?