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.