[R] Determining response variable in a formula

From: David Kane <dave_at_kanecap.com>
Date: Wed 13 Jul 2005 - 00:43:33 EST


I have a formula from which I want to deduce the name of the response variable. One way of doing so is as follows:

> my.form <- as.formula("y ~ x + z")
> all.vars(my.form)[1]

[1] "y"
>

Is there a better way and/or preferrred method of determining "y" from my.form than this one? In messing around with terms, I came up with:

> all.vars(terms(my.form))[attr(terms(my.form), "response")]
[1] "y"
>

But that seems too ugly to be best.

Thanks,

Dave Kane

> R.version

         _
platform i686-pc-linux-gnu

arch     i686             
os       linux-gnu        
system   i686, linux-gnu  
status                    
major    2                
minor    1.0              
year     2005             
month    04               
day      18               
language R                

>


R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Wed Jul 13 00:47:53 2005

This archive was generated by hypermail 2.1.8 : Fri 03 Mar 2006 - 03:33:33 EST