[R] multiple paired t-tests

[Dan Kortschak]

Hi R users,

I have a very large data set that has two conditioning variables for the
test I want to perform.

A toy set can be simulated:

type<-sample(1:3,100,replace=TRUE)
class<-sample(1:20,100,replace=TRUE)
value<-rnorm(100)
data<-cbind(type,class,value)

(though type and class are alphanum)

I want to perform the three pair-wise t-tests between types for each
class in data.

Can someone help me out with this?

Any help is greatly appreciated.
Dan