deriK2000
2010-Dec-10 11:24 UTC
[R] Compare one level of a factor with *all* other non-missing levels
Dear list, I try to compare the mean of a variable given a value of a factor with the mean of the same variable for all K-1 other non-missing values of this factor. This procedure I want to repeat for each level of the factor. Having read the recommendations of this list I want to avoid creating K-1 dummy variables and searched for options of the pairwise.t.test. But couldn't find a solution. Anyone with a suggestion how to do the comparisions? Cheers, Derik -- View this message in context: http://r.789695.n4.nabble.com/Compare-one-level-of-a-factor-with-all-other-non-missing-levels-tp3081777p3081777.html Sent from the R help mailing list archive at Nabble.com.
Peter Ehlers
2010-Dec-10 13:06 UTC
[R] Compare one level of a factor with *all* other non-missing levels
On 2010-12-10 03:24, deriK2000 wrote:> > Dear list, > > I try to compare the mean of a variable given a value of a factor with the > mean of the same variable for all K-1 other non-missing values of this > factor. This procedure I want to repeat for each level of the factor. > > Having read the recommendations of this list I want to avoid creating K-1 > dummy variables and searched for options of the pairwise.t.test. But > couldn't find a solution. Anyone with a suggestion how to do the > comparisions?Sounds like you want the Dunnett test procedure which seems to be implemented in a number of packages: multcomp, asd, MCPAN and others. It would probably be a good idea to install package 'sos' and learn how to search with it. Peter Ehlers> > Cheers, > > Derik