Print out progress reports of add1()
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 at gmail.com <mailto:murdoch.duncan at 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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