However, now a linear regression with a factor for quarterly effect doesn't want to work for me: t2<-lm(mats~time+quar) and I get an error message: "Error in model.frame.default(formula = mats ~ time + quar, drop.unused.levels = TRUE) : variable lengths differ (found for 'quar')"
Which variable has wrong length? Looking forward to a response Ula Unfortunately for me, this example works and does plot fitted line and predicted points. I really don't understand why I can't make the same commands work when trying with my real life data. Ula -- View this message in context: http://www.nabble.com/Plotting-Standard-Regression-Fit-Am-I-wrong-or-a-bug--tp20399460p20401201.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
