[R] Problem with survival

[Terry Therneau]

 It is likely a problem with survival, since
 	2.9 merged in a large number of changes that had occured in my source 
tree that had not propogated to the R tree
 	
 	my test suite doesn't have a test for this particular case (2 factors)
 	
 	and - Murphy's law applies: although almost every possible case is 
covered in the test suite, any new error will hit an omitted combination of 
options with high probability.
 	
 I won't get to it for a few days though.  As with other errors it will result 
in both a fix and an addition to the test suite.
 
 Thank you for a clear explanation of the problem.  
 
 	Terry T.
 	

Dieter Menne wrote:
 "Make sure that this is really a problem with different versions of R,
not a problem of different versions of survival which was changed recently,
without backward compatibility, so that for example many function of
Design (Harrell) do not work currently."

  The comment about backwards compatability is a little unfair.  The code for 
survival curves post Cox model finally added the (long requested) ability to 
accomodate case weights.  This added an argument to a C routine.  The Design 
package called my C routine directly. I was not aware of this, there is no 
promise in any R package that the not-meant-to-be-called-by-others C routines 
won't change, Frank H was told about this as soon as we found out, and he's 
working on it.