Dear Xu Jun, I'm not sure whether this is the source of the error, but it may help to spell the xlevels argument correctly (it is not "xlevles").
I hope this helps, John ------------------------------------------------ John Fox Sen. William McMaster Prof. of Social Statistics Department of Sociology McMaster University Hamilton, Ontario, Canada http://socserv.mcmaster.ca/jfox/ On Thu, 20 Oct 2011 10:34:30 -0400 Xu Jun <junx...@gmail.com> wrote: > Dear r-help listers, > > I am using effects to produce an effect plot after the proportional > odds logistic regression model. There is no problem for me to estimate > the model, but when it comes to the graphing, I was stuck. see the > codes below: > > ############################################################################## > myologit <- polr(factor(warm) ~ yr89 + male + white + age + ed + prst, > + data=ordwarm2, method=c("logistic")) > > require(effects) > plot(effect("age", myologit, xlevles=list(age=seq(20, 80, 5), > given.values(male=1, yr89=1)))) > > ############################################################################## > > I got the following error message: > > Warning message: > package 'effects' was built under R version 2.13.2 > Error in plot(effect("age", myologit, xlevles = list(age = seq(20, 80, : > error in evaluating the argument 'x' in selecting a method for > function 'plot': Error in model.frame.default(formula = factor(warm) ~ > yr89 + male + white + : > variable lengths differ (found for 'yr89') > > > the full set of codes: > > > myologit <- polr(factor(warm) ~ yr89 + male + white + age + ed + prst, > + data=ordwarm2, method=c("logistic")) > > > summary(myologit) > > Re-fitting to get Hessian > > Call: > polr(formula = factor(warm) ~ yr89 + male + white + age + ed + > prst, data = ordwarm2, method = c("logistic")) > > Coefficients: > Value Std. Error t value > yr89 0.523912 0.079899 6.557 > male -0.733309 0.078483 -9.344 > white -0.391140 0.118381 -3.304 > age -0.021666 0.002469 -8.777 > ed 0.067176 0.015975 4.205 > prst 0.006072 0.003293 1.844 > > Intercepts: > Value Std. Error t value > 1|2 -2.4654 0.2389 -10.3188 > 2|3 -0.6309 0.2333 -2.7042 > 3|4 1.2618 0.2340 5.3919 > > Residual Deviance: 5689.825 > AIC: 5707.825 > > > plot(effect("age", myologit, xlevles=list(age=seq(20, 80, 5), > > given.values(male=1, yr89=1)))) > Warning message: > package 'effects' was built under R version 2.13.2 > Error in plot(effect("age", myologit, xlevles = list(age = seq(20, 80, : > error in evaluating the argument 'x' in selecting a method for > function 'plot': Error in model.frame.default(formula = factor(warm) ~ > yr89 + male + white + : > variable lengths differ (found for 'yr89') > > ______________________________________________ > 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.
