Dear Rodrigo, One way to do what you want is by
contrasts(f) <- matrix( c(1, 1, -1, -1, 1, -1, 0, 0, 0, 0, 1, -1), ncol=3) See ?contrasts for details. I hope this helps, John On Sun, 25 Jun 2006 11:48:57 -0300 Rodrigo Gazaffi <[EMAIL PROTECTED]> wrote: > Hello list, > > I would like to know how can I use contrats in statistical analysis. > I > have a simple model, "one-way analysis of variance" "or two-way..." > (balanced case). > > I've already used the command aov (model) to get the analysis of > variance, but i know that my treatment could be organized in groups, > so i would like to test these groups. > > Example: I have 4 treatments t1, t2, t3, t4 and i would like to test > (1, 1, -1, -1) and (1, -1, 0, 0) and (0, 0, 1, -1). > > thanks for the attention. > > Rodrigo Gazaffi > > ______________________________________________ > [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 -------------------------------- John Fox Department of Sociology McMaster University Hamilton, Ontario, Canada http://socserv.mcmaster.ca/jfox/ ______________________________________________ [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
