[R] Weights using Survreg

[Terry Therneau]

The survreg function uses case weights.  That is, if a subject is given
a weight of 2, the result is the same as if there were a second
observation (exactly the same).

Early in my career data sets that contained only categorical variables
were often collapsed in just this way, in order to save on computer
memory and allow the analysis of larger problems. (Continuous variables
such as age might be turned into categorical to facilitate the
collapse). Long, long ago in computer time...
  

Terry Therneau