[R] Plotting of regsubsets adjr2 values not correct

[Greg Snow]

Does your dataset have any missing data? (without a reproducible
example we can only guess).

If it does then you may be fitting the same model to different subsets
of the data between the 2 methods.

On Tue, Sep 25, 2012 at 9:03 AM, Maximilian Lklweryc
<maxlklweryc at gmail.com> wrote:
> Hi,
> I want to make model selection with regsubsets. My code is:
>
> a<-regsubsets(Gesamt ~ CommunistSocialist + CountrySize + GNI + Lifeexp +
> Schoolyears + ExpMilitary + Mortality +
>   PopPoverty + PopTotal + ExpEdu + ExpHealth, data=olympiadaten, nbest=2)
> summary(a)
> plot(a,scale="adjr2")
>
> (output attached)
>
> The problem is now, that I want to fit the best model again "manually" and
> have a look at it, but the value of the adjusted R squared is not the same
> as in the regsubsets output? This is also the case for the other models,
> e.g. when I do the simplest model in the graphic:
> summary(lm(Gesamt~ExpHealth))
> I get an adj. R squared of 0.009202 but the plot says something abou 0.14,
> so it is not correct? I don't know how to solve this problem, any help
> would be nice, thanks.
>
>
> Also I do not understand, which models are shown there, e.g. the simple
> model just with an intercept and the variable GNI is not shown in the plot,
> why?
>
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>



-- 
Gregory (Greg) L. Snow Ph.D.
538280 at gmail.com