This is a slightly modified version of Therneau's survfit.coxph
function.  The difference is that survfit.cph assumes that
x=TRUE,y=TRUE were specified to the fit. This assures that the
environment in effect at the time of the fit (e.g., automatic knot
estimation for spline functions) is the same one used for basing predictions.
# S3 method for cph
survfit(formula, newdata, se.fit=TRUE, conf.int=0.95, 
        individual=FALSE, type=NULL, vartype=NULL,
        conf.type=c('log', "log-log", "plain", "none"), id, …)a fit object from cph or coxph
see survfit.coxph
see
  survfit.  If individual is TRUE,
  there must be exactly one Surv object in newdata.  This 
  object is used to specify time intervals for time-dependent covariate
  paths.  To get predictions for multiple subjects with time-dependent
  covariates, specify a vector id which specifies unique
  hypothetical subjects.  The length of id should equal the
  number of rows in newdata.
Not used
see survfit.coxph