RE : RE : multiple regressions on columns

Hello and thanks for your reply, but as you said, this is not really 

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 

I was just hoping there would be a solution as simple as the one given 

example which gives the results of many regression models of the type 

where i spans all the colums in a matrix and x is one predictor. My 

being the fitting of many regression models of the type y~Xi where i 

the columns in a matrix and y is one dependent variable.

Best regards,

David Gouache
ARVALIS - Institut du v?g?tal
Station de La Mini?re
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] 
Envoy? : mardi 24 f?vrier 2009 18:22
? : 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 

package and the leaps package can do some things along this line (plus 

But before doing this, you may want to ask yourself what question you 

really trying to answer, then explore if this answers that question or 

-- 
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 v?g?tal
Station de La Mini?re
78280 Guyancourt
Tel: 01.30.12.96.22 / Port: 06.86.08.94.32