[R] survival curves for time dependent covariates (was "consultation")

[Terry Therneau]

*I´m writing to ask you how can I do Survivals Curves using Time-dependent
*covariates? Which packages I need to Install?*

  This is a very difficult problem statistically.  That is, there are not many 
good ideas for what SHOULD be done.  Hence, there are no packages. Almost 
everything you find in an applied paper (e.g. a medical journal) is wrong.
  
     Terry Therneau