[R] Weighting data when running regressions

[Elena Wilson]

It works!!!
Thanks a lot Chuck!

-----Original Message-----
From: Chuck Cleland [mailto:ccleland at optonline.net] 
Sent: Monday, 10 March 2008 11:29 PM
To: Elena Wilson
Cc: r-help at r-project.org
Subject: Re: [R] Weighting data when running regressions

On 3/10/2008 7:49 AM, Elena Wilson wrote:
> Dear R-Help,   
> 
> I'm new to R and struggling with weighting data when I run regression.
I've
> tried to use search to solve my problem but haven't found anything helpful
> so far.
> 
> I (successfully) import data from SPSS (15) and try to run a linear
> regression on a subset of my data file where WEIGHT is the name of my
> weighting variable (numeric), e.g.:
> 
> library(foreign)
> 
> data1=read.spss("File.sav", use.value.labels = FALSE, to.data.frame =
TRUE)
> 
> summary(data1) ' shows me all the variables OK
> 
> attach(data1)
> 
> linmod=lm(Y~X1+X2+X3+X4W, subset=(X5==1 & X6==7), weights==WEIGHT)
> 
> and I get the following Error message:
> 
> Error in weights == WEIGHT : 
> 
>   comparison (1) is possible only for atomic and list types
> 
> It works perfectly if I don't use the ", weights==WEIGHT" bit

   Try it with just one equals sign after weights:

linmod=lm(Y~X1+X2+X3+X4W, subset=(X5==1 & X6==7), weights=WEIGHT)

> Could you please let me know what I am doing wrong? 
> 
> Thank you in advance, 
> 
> Lena
> 
> 	[[alternative HTML version deleted]]
> 
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-- 
Chuck Cleland, Ph.D.
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