R help - Aug 2004 - Question on TukeyHSD

Hi,
	I am running a ANOVA on a factorial design, and using TukeyHSD
for post hoc comparisons. I have 2 factors with three levels each:
		Factor B
Factor A    1   2   3
	1
	2
	3


When I look at the Tukey output (on the interaction of the factors) the
comparisons come out numbered 1-36. 

e.g.
$"A:B"
             diff         lwr      upr
[1,]  49.1666667 -160.041022 258.3744
[2,]  50.0000000 -159.207689 259.2077
....

[35,]  84.3333333 -124.874355 293.5410
[36,]  57.6666667 -151.541022 266.8744

Does anyone know how the function numbers the comparisons or an easy way
of figuring out the order without having to go back and calculate the
means between each pair and then going back to compare them with the
output?

Thank you in advance

Hem Nalini Morzaria-Luna
Department of Botany
UW-Madison
341 Birge Hall
430 Lincoln Drive
Madison, WI 53706
(608) 265 9722

On Thu, 19 Aug 2004, Hem Nalini Morzaria-Luna wrote:
> Hi,
> 	I am running a ANOVA on a factorial design, and using TukeyHSD
> for post hoc comparisons. I have 2 factors with three levels each:
> 		Factor B
> Factor A    1   2   3
> 	1
> 	2
> 	3
> 
> 
> When I look at the Tukey output (on the interaction of the factors) the
> comparisons come out numbered 1-36. 
Rather, they come out as unlabelled and this is a print of a matrix 
without rownames.
> e.g.
> $"A:B"
>              diff         lwr      upr
> [1,]  49.1666667 -160.041022 258.3744
> [2,]  50.0000000 -159.207689 259.2077
> ....
> 
> [35,]  84.3333333 -124.874355 293.5410
> [36,]  57.6666667 -151.541022 266.8744
> 
> Does anyone know how the function numbers the comparisons 
It doesn't.   However, this is standard R order, that is down columns
(1:1, 2:1, 3:1 etc).
> or an easy way of figuring out the order without having to go back and
> calculate the means between each pair and then going back to compare
> them with the output?
It should be easy to add labels for the next release.

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595