[R] Survreg(), Surv() and interval-censored data

[Terry Therneau]

The question (slightly rephrased) was
  Why does survreg(Surv(T.1, T.2, type='interval2') ~1, data=x) fail, when x is

         T.1          T.2      Status
1  0.0000000   0.62873036      1
2  0.0000000   2.07039068      1
3  0.0000000   1.40297214      1
4  0.0000000   0.09112871      1
5  0.0000000   0.75115280      1
6  0.0000000   2.36476839      1
...

----------------

  The default model for survreg is a Weibull, for which a survival time of 
exactly zero is not a valid value.  Your example triggers this error message. 

  This is a bug in survreg.  In the 10+ years the code has been available, no 
one has ever specified this particular data: a (0,x] interval for a Weibull.  
Congratulations!  Fixing this will require some thought, however.
  
  To work around the problem, change 0 to NA, which marks the observation as 
left-censored.  
  
  	Terry Therneau
  	(author of survreg)