Displaying 20 results from an estimated 11000 matches similar to: "data level for stepwise"
2011 Jun 21
1
Stepwise Manova
Hello all,
I have a question on manova in R:
I'm using the function "manova()" from the stats package.
Is there anything like a stepwise (backward or forward) manova in R (like there is for regression and anova).
When I enter:
step(Model1, data=Mydata)
R returns the message:
Error in drop1.mlm(fit, scope$drop, scale = scale, trace = trace, k = k, :
no 'drop1'
2010 Aug 14
2
Stepwise Regression + entry/exit significance level
Hi R,
Does the "step" function used to perform stepwise regression has the
option to specify the entry/exit significance levels for the independent
variables? (This is similar to the 'slentry' and 'slstay' option in
'Proc reg' of SAS.). Or do we have any other package which does the
above? Thanks.
Thanks and Regards,
Shubha
This e-mail may
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
2005 Feb 25
0
Bayesian stepwise (was: Forward Stepwise regression based onpartial F test)
oops,
Forgot to cc to the list.
Regards,
Mike
-----Original Message-----
From: dr mike [mailto:dr.mike at ntlworld.com]
Sent: 24 February 2005 19:21
To: 'Spencer Graves'
Subject: RE: [R] Bayesian stepwise (was: Forward Stepwise regression based
onpartial F test)
Spencer,
Obviously the problem is one of supersaturation. In view of that, are you
aware of the following?
A Two-Stage
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
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
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
2004 Nov 09
3
no doubt a dumb question, but..
Yes, I am a newbie at R, but it is not the complex commands in R that
have me baffled, but simple data commands. For example, why does
something like:
> plot(Girth ~ Height)
*not* work after a command that allegedly loads the data:
> data(trees)
with the error message:
Error in eval(expr, envir, enclos) : Object "Girth" not found
but does work after the command:
>
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
2000 Nov 01
0
Forward stepwise regression
I have a question regarding doing forward stepwise regression using the step function and an lm model.
I am trying to run a stepwise procedure that will add a predictor variable, one at a time, conduct an F test to determine whether or not to drop any previous terms, and terminate when no other predictors qualify to be added. Using the step function and looking at the example in the book, I
2011 Jul 07
1
Automated stepwise multiple linear regression
Dear forum members,
hope you can understand my unprofessionell English. I have never been
working with RStudio before (even not with R), so I immediately need some
help, because I want to carry out an automated multiple stepwise linear
regression between temperatures and different surface parameters.
Data can be found in several .xls- or .csv-files within one folder. Files
are named
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
--
View this message in context: http://www.nabble.com/Bayesian-regression-stepwise-function--tp26013725p26013725.html
Sent from
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
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]]
2001 Nov 30
1
Stepwise regression
I need to do a classic stepwise regression based not on AIC but on F in and
F out (or on R2, or R2 adjusted). I have many variables and it will very
useful for me to have a fast stepwise algorithm. Does anyone know if this
exists for R and where I can find that ?
Thank you very much.
Pascal Grandeau
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing
2012 Mar 05
1
Forward stepwise regression using lmStepAIC in Caret
I'm looking for guidance on how to implement forward stepwise regression
using lmStepAIC in Caret.
The stepwise "direction" appears to default to "backward". When I try to
use "scope" to provide a lower and upper model, Caret still seems to
default to "backward".
Any thoughts on how I can make this work?
Here is what I tried:
itemonly <-
2008 Sep 04
1
Stepwise
Hi,
Is there any facility in R to perform a stepwise process on a model,
which will remove any highly-correlated explanatory variables? I am told
there is in SPSS. I have a large number of variables (some correlated),
which I would like to just chuck in to a model and perform stepwise and
see what comes out the other end, to give me an idea perhaps as to which
variables I should focus on.
Thanks
2009 Oct 13
1
stepwise with F statistics
Hi Community R
I need to make a stepwise using F statistics as a criteria to choose variables.I have 3 independant variables and one dependant variable, and I need to choose the best model fitting to my data using F statistics. The problem is I haven't found any package to do such operation. I have found packages to choose variables using significance level like "stepback" from
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
2003 May 08
2
Forward Stepwise regression with stepAIC and step
Dear all,
I cannot seem to get the R functions step or stepAIC to perform forward
or stepwise regression as I expect. I have enclosed the example data in
a dataframe at the end of this mail. Note rubbish is and rnorm(17) variable
which I have deliberately added to the data to test the stepwise procedure.
I have used
wateruse.lm<-lm(waterusage~.,data=wateruse) # Fit full model