[R] for loop and linear models

[William Dunlap]

Your suggestion would have it return after fitting
the first model, which is not what the OP wants.

The basic problem is that
    models <- list(lm(...))
replaces the old value of models with a new length-1
list.  You want to add the new fitted model to the
list of fitted models.  E.g.,
    models <- list() # make empty list
    for(...) for(...) {
        models[[colnames(x)[i]]] <- lm(...) # append named element to
list
    }

There are lots of other ways to do this.

Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com  

> -----Original Message-----
> From: r-help-bounces at r-project.org 
> [mailto:r-help-bounces at r-project.org] On Behalf Of Daniel Malter
> Sent: Monday, June 20, 2011 1:05 PM
> To: r-help at r-project.org
> Subject: Re: [R] for loop and linear models
> 
> To be more accurate and helpful, try this:
> 
> fun<- function(x,y){ 
>             for(i in 1:length(colnames(x))){ 
>               for(j in 1:length(colnames(y))){ 
>                if(colnames(x)[i]==colnames(y)[j]){ 
>                models=list(lm(ts(x[i])~ts(y[j]))) 
>                return(models) 
>                } 
>                else{} 
>             } 
>           } 
> } 
> 
> 
> :) Does this do it for you?
> Daniel
> 
> 
> hazzard wrote:
> > 
> > Hi,
> > 
> > I have two datasets, x and y. Simplified x and y denote:
> > 
> >  X
> > 
> > Y
> > 
> >  A B C A B C  . . . . . .  . . . . . .  . . . . . .
> > I want to implement all possible models such as 
> lm(X$A~Y$A), lm(X$B~Y$B),
> > lm(X$C~Y$C)... I have tried the following:
> > 
> > fun<- function(x,y){
> >             for(i in 1:length(colnames(x))){
> >               for(j in 1:length(colnames(y))){
> >                if(colnames(x)[i]==colnames(y)[j]){
> >                models=list(lm(ts(x[i])~ts(y[j])))
> >                }
> >                else{}
> >             }
> >           }
> >            return(models)
> > }
> > 
> > The problem is that this returns only one of the three 
> models, namely the
> > last one. What am I doing wrong? Thank you very much in advance.
> > 
> > Regards
> > 
> > 	[[alternative HTML version deleted]]
> > 
> > ______________________________________________
> > 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.
> > 
> 
> --
> View this message in context: 
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2274p3612392.html
> Sent from the R help mailing list archive at Nabble.com.
> 
> ______________________________________________
> 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.
>