Storage of objects of class=survdiff

["Paul, David A" <paulda@BATTELLE.ORG>]

I would like to program a for-loop to calculate a set of survdiff objects
and store these results in another Splus object, like a
vector/matrix/dataframe.  
For example:

survdiff.collection <- rep(NA,20)
rho.value <- rep(NA,20)
for(i in 1:21){
        rho.value[i] <- 1-.1*(i-1)
        survdiff.collection[i] <- survdiff(Surv(Time.of.Death,Event.Status)
                ~Dose.Group,data=Data.Frame,rho=rho.value[i])
}

This naive approach doesn't work because the members of the vector
survdiff.collection
cannot handle the structured objects that survdiff( ) generates.

Is there a way to create a vector/matrix/dataframe capable of storing
objects of 
class="survdiff"?

 David Paul, Ph.D.
  Battelle Memorial Institute
  505 King Avenue
  Columbus, OH  43201
  614.424.3176