Jen-Chien and Adaikalavan, Weekday is specified as an ordered factor, for which the default contrast type is contr.poly, i.e., orthogonal-polynomial contrasts. I would have expected a 6th-degree polynomial for the 7 days of the week, and there's a message that suggests that 3 coefficients are aliased, so there must be redundancies among the factors. If you want contr.treatment, treating "Mon" as the baseline level, then simply omit ordered=T from the call to factor(), but this won't make the collinearities disappear.
I hope this helps, John ------------------------------ John Fox, Professor Department of Sociology McMaster University Hamilton, Ontario, Canada web: socserv.mcmaster.ca/jfox > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf Of Adaikalavan Ramasamy > Sent: November-02-09 10:43 AM > To: Jen-Chien Chang > Cc: r-help@r-project.org > Subject: Re: [R] how to print the full name of the factors in summary? > > It would be useful to say which package the object SJ comes from or > provide a more reproducible example. > > Assuming that Demand variable is continuous and you are fitting a > standard lm() model, then your results looks suspicious. Where are the > coefficients for Month, Holiday, Season? > > > > > Jen-Chien Chang wrote: > > Hi, > > > > I am wondering if there is a simple way to fix the problem I am having. > > For unknown reason, I could not get the full name of the factors to be > > printed in the summary. I have tried to used summary.lm as well but the > > problem still persists. > > > > SJ$Weekday <- > > > factor(SJ$Weekday,1:7,c("Mon","Tue","Wed","Thu","Fri","Sat","Sun"),ordered=T ) > > > > .... > > attach(SJ) > > lm.SJ <- lm(Demand ~ Weekday+Month+Holiday+Season) > > summary(lm.SJ) > > Call: > > lm(formula = Demand ~ Weekday + Month + Holiday + Season) > > > > Residuals: > > Min 1Q Median 3Q Max > > -69.767 -12.224 -1.378 10.857 91.376 > > > > Coefficients: (3 not defined because of singularities) > > Estimate Std. Error t value Pr(>|t|) > > (Intercept) 88.7091 3.3442 26.527 < 2e-16 *** > > Weekday.L 20.8132 2.8140 7.396 1.08e-12 *** > > Weekday.Q -12.7667 2.8156 -4.534 7.99e-06 *** > > Weekday.C -10.6375 2.8113 -3.784 0.000182 *** > > Weekday^4 -8.3325 2.8103 -2.965 0.003238 ** > > --------------------------------------------- > > > > Is there a way for summary to print the full name of the factors and > > levels? Say Weekday.Tue instead Weekday.L? > > > > Thanks! > > > > Jack Chang > > > > ______________________________________________ > R-help@r-project.org mailing list > 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. ______________________________________________ R-help@r-project.org mailing list 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.