
Hello everybody,
I would like to calculate the median for each factor combination, with only one value per factor combination as an output.
Could anybody help me?


For example:
# make table
g<-1:2
group<-rep(g, each=5)
session<-c(1,1,2,2,2,1,1,1,2,2)
rt<-seq(length=10,300, 800)
rt<-round(rt, digits=2)
table<-data.frame(group, session, rt)
table

   group session     rt
1      1       1 300.00
2      1       1 355.56
3      1       2 411.11
4      1       2 466.67
5      1       2 522.22
6      2       1 577.78
7      2       1 633.33
8      2       1 688.89
9      2       2 744.44
10     2       2 800.00




Besides others I tried the following:
median<-ave(rt, group, session, FUN=median)
median<-frameApply(table,by=c("group", "session"), on="rt", fun=median)

I would appreciate your help a lot.
Marianne 		 	   		  
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