[R] Print out progress reports of add1()

[Duncan Murdoch]

On 18/01/2021 12:08 p.m., Chao Liu wrote:
> Thank you Duncan. Do you by chance know any way around this?

I don't see any need for a trace when there's only one fit being done. 
The tests that are shown are all you need.

Duncan Murdoch


> 
> On Mon, Jan 18, 2021 at 11:58 AM Duncan Murdoch 
> <murdoch.duncan using gmail.com <mailto:murdoch.duncan using gmail.com>> wrote:
> 
>     You are using add1 on an "lm" object, and add1.lm doesn't have a trace
>     parameter.
> 
>     Duncan Murdoch
> 
>     On 18/01/2021 10:55 a.m., Chao Liu wrote:
>      > I have a few questions about using add1(). First of all,
>     according to the R
>      > document of add1(), the trace = TRUE function prints out progress
>     reports
>      > but my attempts to do this have failed several times. So how do
>     we print
>      > out the progress reports of adding terms to the model so as to
>     test for
>      > improved fit (or not)? Also, why the LRT (likelihood-ratio test)
>     value is
>      > not in the output? Any help is greatly appreciated! Example as
>     follows:
>      >
>      > require(graphics); require(utils)
>      > lm1 <- lm(Fertility ~ ., data = swiss)
>      > add1(lm1, scope = .~. + .^2, test="Chisq", trace = TRUE)
>      >
>      > #It seems that no progress report has been printed. Also `LRT` is
>     missing
>      > Single term additions
>      >
>      > Model:
>      > Fertility ~ Agriculture + Examination + Education + Catholic +
>      >      Infant.Mortality
>      >                               Df Sum of Sq  RSS AIC Pr(>Chi)
>      > <none>                                    2105 191
>      > Agriculture:Examination       1      10.7 2094 192   0.6251
>      > Agriculture:Education         1       1.8 2103 193   0.8399
>      > Agriculture:Catholic          1      75.0 2030 191   0.1915
>      > Agriculture:Infant.Mortality  1       4.4 2101 193   0.7528
>      > Examination:Education         1      48.7 2056 192   0.2943
>      > Examination:Catholic          1      40.8 2064 192   0.3378
>      > Examination:Infant.Mortality  1      65.9 2039 191   0.2216
>      > Education:Catholic            1     278.2 1827 186   0.0099 **
>      > Education:Infant.Mortality    1      93.0 2012 191   0.1451
>      > Catholic:Infant.Mortality     1       2.4 2103 193   0.8184
>      > ---
>      > Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
>      >
>      > Best,
>      >
>      > Chao
>      >
>      >       [[alternative HTML version deleted]]
>      >
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