Dear Professor Fox, I didn't include codes in between these two commands (polr and plot(effect()). I am still trying to work it out. Maybe it's related to how I coded some of the factor variables as I got some successful runs after I changed the coding for some factor variables. I will keep working on the codes and see if I can figure out. Again, your effects package, I have to say, is awesome!
Jun On Thu, Oct 20, 2011 at 1:26 PM, Xu Jun <junx...@gmail.com> wrote: > Dear Professor Fox, > > Thanks a lot! That is an embarrassing error. After I cleaned up and > simplified my codes, and ran the following two lines: > > myologit <- polr(factor(warm) ~ yr89 + male + white + age + ed + prst, > + data=ordwarm2, method=c("logistic")) > > plot(effect("age", myologit, xlevels=list(age=seq(20, 80, 5)))) > > I am still having trouble. See below: > >> 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, xlevels=list(age=seq(20, 80, 5)))) > Error in plot(effect("age", myologit, xlevels = 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') > > On Thu, Oct 20, 2011 at 11:55 AM, John Fox <j...@mcmaster.ca> wrote: >> 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.