Anova, for loop to apply function

Question

>str(set)
\'data.frame\':   1000 obs. of  6 variables:
$ ID       : Factor ..
$ a : Factor ..
$ b: Factor ..
$ c: Factor ..
$ dat    : num  ..
$ contrasts : Ord.f         


        

Answer 1

This ought to do it:

# Sample data
set <- data.frame(ID=1:10, a=letters[1:10], b=LETTERS[1:10], c=letters[10:1],
                  dat=runif(10), contrasts=ordered(rep(1:2, 5)))
X <- letters[1:3] # a,b,c

sapply(X, function(my) {
  f <- as.formula(paste("dat~contrasts*",my,"+Error(ID/(contrasts))"))
  summary(aov(f, data=set))
}, simplify=FALSE)

Note the use of sapply with simplify=FALSE. Using lapply also works, but it doesn't add names to the list components.