[R] How is the line in av.plot calculated?

[Chuck Cleland]

Tom La Bone wrote:
> I suspect that the line in the added variable plot (library car) is a SLR of
> the residuals, but I can't seem to find this written anywhere.  Can someone
> confirm this?  Thanks.

  See the Fox(1997) reference on the help page (pages 281-283).  Note
that both the x-axis and the y-axis are residuals.  For example, you
could do the av.plot for income in the Duncan data as follows:

library(car)

res1 <- residuals(lm(prestige ~ education+type, data=Duncan))
res2 <- residuals(lm(income ~ education+type, data=Duncan))

plot(res2, res1)
abline(lm(res1 ~ res2))

> Tom
> 
>  
> 
> 
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> 
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-- 
Chuck Cleland, Ph.D.
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