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 <[email protected] <mailto:[email protected]>> 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]] > > ______________________________________________ > [email protected] <mailto:[email protected]> mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help <https://stat.ethz.ch/mailman/listinfo/r-help> > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html <http://www.R-project.org/posting-guide.html> > and provide commented, minimal, self-contained, reproducible code. >
______________________________________________ [email protected] mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
