Displaying 20 results from an estimated 6000 matches similar to: "Bayesian stepwise (was: Forward Stepwise regression based onpartial F test)"
2005 Feb 24
2
Forward Stepwise regression based on partial F test
I am hoping to get some advise on the following:
I am looking for an automatic variable selection procedure to reduce the
number of potential predictor variables (~ 50) in a multiple regression
model.
I would be interested to use the forward stepwise regression using the
partial F test.
I have looked into possible R-functions but could not find this
particular approach.
There is a function
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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2008 Oct 22
1
forward stepwise regression using Mallows Cp
So I recognize that:
1. many people hate forward stepwise regression (i've read the archives)--but I need it
2. step() or stepAIC are two ways to get a stepwise regression in R
But here's the thing: I can't seem to figure out how to specify that I want the criteria to be Mallow's Cp (and then to subsequently tell me what the Cp stat is). I know it has something to do with
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
2007 Sep 17
1
Stepwise logistic model selection using Cp and BIC criteria
Hi,
Is there any package for logistic model selection using BIC and Mallow's Cp
statistic? If not, then kindly suggest me some ways to deal with these
problems.
Thanks.
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2006 Jan 31
1
Stepwise selection and F-enter anf F-remove values
Hello,
I'm actually using the "Step" procedure in R for multiple regression analysis.
I'm using the stepwise selection which alternates between forward selection
and backward elimination (direction "both" in the step procedure).
I would like to know which F-levels R is using to enter and then to remove
variables?
I also would like which is the procedure to change
2007 Nov 15
0
Package to make stepwise model selection using F or Chisq test
Hi,
I looking for a method that use F or Chisq test instead of AIC in a stepwise
modelo selection.
I try the grasp package using the grasp.step.anova, but It dont work.
> library(grasp)
Carregando pacotes exigidos: gam
Carregando pacotes exigidos: splines
Carregando pacotes exigidos: mda
Carregando pacotes exigidos: class
> data(anorexia,package="MASS")
>
> m1 <-
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
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 <-
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
2007 Apr 01
3
Doing partial-f test for stepwise regression
Hello all,
I am trying to figure out an optimal linear model by using stepwise
regression which requires partial f-test, I did some Googling on the
Internet and realised that someone seemed to ask the question before:
Jim Milks <jrclmilks at joimail.com> writes:
> Dear all:
>
> I have a regression model that has collinearity problems (between
> three regressor variables). I
2000 Jun 07
1
forward stepwise selection
Dear R-Help,
My problem/bug came to light,when fitting a linear model using stepwise
selection. I'd started with the straightfoward command
step(lm(y~., dataset))
This worked fine, but because this starts with all the possible
explanatory variables, it results in a model with too many explanatory
variables. Hence I wanted to start with just a constant and do forward
selection, to get a
2004 Feb 01
5
Stepwise regression and PLS
Dear all,
I am a newcomer to R. I intend to using R to do stepwise regression and
PLS with a data set (a 55x20 matrix, with one dependent and 19
independent variable). Based on the same data set, I have done the same
work using SPSS and SAS. However, there is much difference between the
results obtained by R and SPSS or SAS.
In the case of stepwise, SPSS gave out a model with 4 independent
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
2011 Feb 09
0
Course: "Introduction to Bayesian Data Analysis using WinBUGS and R"
Apologies for cross-posting. Places are available in the following
course:
"Introduction to Bayesian Data Analysis using WinBUGS and R"
Best Regards,
Pablo
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Course: Introduction to Bayesian Data Analysis using WinBUGS and R
Where: Linux Hotel, Essen-Horst, Germany
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
2012 Apr 16
0
COURSE: Introduction to Bayesian Data Analysis using WinBUGS and R, 21-23 Juni 2012
Dear list members,
Apologies for cross-posting. Please, find below the information of
an introductory Bayesian Data Analysis course with WinBUGS and R.
If you have any question don't hesitate to contact me.
Best regards,
Pablo
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Course: Introduction to Bayesian Data Analysis using WinBUGS and R
Where: Linux Hotel, Essen-Horst,
2003 Jun 18
2
Forward stepwise procedure w/ stepAIC
I'm attempting to select a model using stepAIC. I want to use a forward
selection procedure. I have specified a "scope" option, but must not be
understanding how this works. My results indicate that the procedure begins
and ends with the "full" model (i.e., all 17 independent variables)...not
what I expected. Could someone please point out what I'm not