Dear R-help,

I'm facing a problem with defining a repeated measures anova with  
weighted data.
Here's the code to reproduce the problem:

# generate some data
seed=11
rtrep <- data.frame(rt=rnorm(100),ti=rep(1:5,20),subj=gl 
(20,5,100),we=runif(100))

# model with within factor for subjects/repeated measurements, no  
problem
aov(rt~ti + Error(subj/ti),data=rtrep)

#model with weights and subj as between factor, ie ignoring repeated  
measures,
#again, no problem
aov(rt~ti+subj,data=rtrep,weights=we)

#combination of above two: repeated measures AND weights
aov(rt~ti + Error(subj/ti),data=rtrep,weights=we)

The latter model gives an error (see report below), but only after  
fitting it, ie the error is produced by the
print and summary methods of the aov objects.

Any guidance is appreciated, best, Ingmar





Error produced in printing the fitted aov object:

Call:
aov(formula = rt ~ ti + Error(subj/ti), data = rtrep, weights = we)
Note: The results below are on the weighted scale

Grand Mean: 0.112081

Stratum 1: subj

Terms:
                        ti Residuals
Sum of Squares   2.002826 10.869940
Deg. of Freedom         1        18

Residual standard error: 0.7771007
Estimated effects are balanced

Stratum 2: subj:ti

Terms:
                       ti Residuals
Sum of Squares  0.382535  5.540047
Deg. of Freedom        1        19

Residual standard error: 0.5399828
Estimated effects are balanced

Stratum 3: Within
Error in print.aov(xi, ...) :
   dims [product 60] do not match the length of object [100]
In addition: Warning message:
In resid * wt^0.5 :
   longer object length is not a multiple of shorter object length


Ingmar Visser
Department of Psychology, University of Amsterdam
Roetersstraat 15
1018 WB Amsterdam
The Netherlands
t: +31-20-5256723



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