[R] Odp: RE : multiple regressions on columns

[Petr PIKAL]

Hi

If you do not insist on matrix and use data frame instead

lapply(iris4,function(x) lm(iris$Sepal.Length~x))

can do it

Regards
Petr

r-help-bounces at r-project.org napsal dne 25.02.2009 09:56:25:

> Hello and thanks for your reply, but as you said, this is not really 
what I'm 
> trying to do.
> My purpose is not one of variable selection within a model with multiple 

> predictors, but simply fitting a large number of models with only one 
predictor.
> I was just hoping there would be a solution as simple as the one given 
in my 
> example which gives the results of many regression models of the type 
Yi~x 
> where i spans all the colums in a matrix and x is one predictor. My 
objective 
> being the fitting of many regression models of the type y~Xi where i 
spans all
> the columns in a matrix and y is one dependent variable.
> 
> Best regards,
> 
> David Gouache
> ARVALIS - Institut du végétal
> Station de La Minière
> 78280 Guyancourt
> Tel: 01.30.12.96.22 / Port: 06.86.08.94.32
> 
> 
> -----Message d'origine-----
> De : Greg Snow [mailto:Greg.Snow at imail.org] 
> Envoyé : mardi 24 février 2009 18:22
> À : GOUACHE David; r-help at stat.math.ethz.ch
> Objet : RE: multiple regressions on columns
> 
> The add1 function might be what you want, there is also addterm in the 
MASS 
> package and the leaps package can do some things along this line (plus 
more).
> 
> But before doing this, you may want to ask yourself what question you 
are 
> really trying to answer, then explore if this answers that question or 
not.
> 
> -- 
> Gregory (Greg) L. Snow Ph.D.
> Statistical Data Center
> Intermountain Healthcare
> greg.snow at imail.org
> 801.408.8111
> 
> 
> > -----Original Message-----
> > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> > project.org] On Behalf Of GOUACHE David
> > Sent: Tuesday, February 24, 2009 10:13 AM
> > To: r-help at stat.math.ethz.ch
> > Subject: [R] multiple regressions on columns
> > 
> > R-helpers,
> > 
> > A quick question regarding my wanting to run multiple regressions
> > without writing a loop.
> > Looking at a previous discussion :
> > http://tolstoy.newcastle.edu.au/R/e2/help/07/02/9740.html
> > 
> > my objective is to do the "opposite", i.e. instead of having the same
> > independent variable and testing it against multiple dependent
> > variables, my goal is to test multiple independent variables against
> > the same dependent variable.
> > 
> > Using the iris dataset:
> > 
> > iris4 <- as.matrix(iris[,-c(1,5)])
> > summary(lm(iris4 ~ Sepal.Length, iris))
> > 
> > what I would have liked is to do the following :
> > 
> > summary(lm(Sepal.Length ~ iris4, iris))
> > 
> > and obtain the results from 3 separate regressions, as above, instead
> > of one multiple regression...
> > 
> > Any clues ?
> > 
> > Tanks in advance
> > 
> > David Gouache
> > ARVALIS - Institut du végétal
> > Station de La Minière
> > 78280 Guyancourt
> > Tel: 01.30.12.96.22 / Port: 06.86.08.94.32
> > 
> > ______________________________________________
> > R-help at r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide http://www.R-project.org/posting-
> > guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> 
> ______________________________________________
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> and provide commented, minimal, self-contained, reproducible code.