Hi everyone,

Using the following data, I need to determine if, independent of mass, 
the observed response is associated with sex, location, and/or age

|example<-data.frame(response=c(2.401,2.588,2.293,2.880,2.655,2.830,3.165,2.665,3.126,2.973,1.725,1.889,2.631,1.750,2.271,2.347,2.173,1.962,1.599,2.297,1.894,2.030),mass=c(460,510,500,475,450,470,600,570,480,560,410,370,425,385,400,420,490,450,390,465,360,490),
loc=c("K","K","K","K","K","K","K","K","K","K","R","R","R","R","R","R","R","R","R","R","R","R"),sex=c("F","M","M","F","M","F","M","M","F","M","F","F","M","F","F","F","M","F","F","M","F","F"),|
|age 
=c(48,49,47,45,49,49,50,48,49,48,47,48,47,50,48,50,48,50,48,50,50,50))|

This should be relatively simple but I've been hung up on it for a few 
days now and could use a hand. If I understand it correctly, in order to 
run an ANCOVA in R I need to set the contrasts from their default 
(non-orthogonal) to orthogonal. I'm struggling to find the best method 
to do this. Admittedly, contrast matrices are a new challenge I have yet 
to master which isn't helping. Any assistance would be greatly appreciated.

Once the orthogonal contrasts are set, I'm guessing everything else is 
straightforward (with pkg 'car' installed):

model.1=aov(response~mass+loc+sex+age,data=example)
Anova(model.1,type="III")
Summary.lm(model.1)
|
Many thanks in advance,
G
|

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