[R] add a point to regression line and cook's distance

[Wiener, Matthew]

If you know that the line should pass through (0,0), would it make sense to
do a regression without an intercept?  You can do that by putting "-1" in
the formula, like:  lm(y ~ x - 1).

Hope this helps,

Matt

Matthew Wiener
RY84-202
Applied Computer Science & Mathematics Dept.
Merck Research Labs
126 E. Lincoln Ave.
Rahway, NJ 07065
732-594-5303 


-----Original Message-----
From: r-help-bounces at stat.math.ethz.ch
[mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Spencer Graves
Sent: Wednesday, December 03, 2003 5:51 PM
To: jonathan_li at agilent.com
Cc: r-help at stat.math.ethz.ch
Subject: Re: [R] add a point to regression line and cook's distance


      What is the context?  What do the "outliers" represent?  If you 
think carefully about the context, you may find the answer. 

      hope this helps.  spencer graves
p.s.  I know statisticians who worked for HP before the split and who 
still work for either HP or Agilent, I'm not certain which.  If you want 
to contact me off-line, I can give you a couple of names if that might 
help. 

jonathan_li at agilent.com wrote:

>Hi, 
>
>This is more a statistics question rather than R question. But I thought
people on this list may have some pointers.
>
>MY question is like the following:
>I would like to have a robust regression line. The data I have are mostly
clustered around a small range. So
>the regression line tend to be influenced strongly by outlier points (with
large cook's distance). From the application
>'s background, I know that the line should pass (0,0), which is far away
from the data cloud. I would like to add this
>point to have a more robust line. The question is: does it make sense to do
this? what are the negative impacts if any?
>
>thanks,
>jonathan
>
>______________________________________________
>R-help at stat.math.ethz.ch mailing list
>https://www.stat.math.ethz.ch/mailman/listinfo/r-help
>  
>

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