[R] Manova

Göran Broström
Thu, 18 Dec 2003 10:24:47 -0000

Dear R-helpers,

In a data set I got from a medical doctor there are six treatment groups
and (about) 5 bivariate responses in each group. Using 'manova', it is
easy to see significant differences in treatment effects, but the doctor
is more interested in the correlation between the two responses (within
groups). I'm willing to assume a common value over groups, and one way
of estimating and testing the common correlation would be to use
'cor.test' on the residuals from 'manova', but I guess that the
resulting p-value (from testing zero correlation) will be far too
optimistic (it is in fact 4.5e-5).

What is the 'right' way of doing this in R?
--
 G?ran Brostr?m                    tel: +46 90 786 5223
 Department of Statistics          fax: +46 90 786 6614
 Ume? University                   http://www.stat.umu.se/egna/gb/
 SE-90187 Ume?, Sweden             e-mail: gb at stat.umu.se