Bond, Stephen wrote: > I need to use contr.sum and observe that some levels are not > statistically different from the overall mean of zero. What is the > proper way of forcing the zero estimate? It seems the column > corresponding to that level should become a column of zeros. Is there > a way to achieve that without me constructing the design matrix?
As Berwin (indirectly) points out, you probably overlooked the how.many argument to C(). However, are you _sure_ that you want to do this? This is like testing that one treatment is exactly equal to the average of all other treatments, which is a rather strange hypothesis. -- Peter Dalgaard Center for Statistics, Copenhagen Business School Phone: (+45)38153501 Email: [email protected] Priv: [email protected] ______________________________________________ [email protected] 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.
