On Fri, 24 Jun 2011, oyvfos wrote:
The replication of the error did not "suceed" because I forgot to tell that X2 is a factor. Sorry about that. For instance: d[,3]=as.factor(d[,3]) This piece is just a small sample of a larger error for which I encouneter this error many times.
You try to estimate coefficients for levels with very few observations. In particular for one level, the number of occurrences is only _one_. This creates problems if you want to compute measures of reliability (which are required in beta regression residuals).
If you want to get the usual coefficient table with partial Wald tests, you can still do so via coeftest(m), as illustrated in the vignette. The results will, of course, not be very meaningful for those coefficients estimated from just one observation...
However, if you want to have a model that is interpretable as a whole, then include only levels whose coefficients can be estimated meaningfully.
In your demo case, you need to exclude at least the level "700". Best, Z
Thanks -- View this message in context: http://r.789695.n4.nabble.com/Error-using-betareg-tp3621955p3622300.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.
______________________________________________ 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.
