Internal non-linear transformation model functions.
nltm.fit(x1, x2, y, model, init, control, verbose)
profileLikR(beta, x1, x2, status, count, s0, model, cure, tol, nvar1,
nvar2, nobs, npred, verbose)
boundary(x1, x2, npred, cure, bscale)
counts(time, status)
eventTimes(y)
initSurvival(count, cure)
nPredictor(model)
reverseCumsum(a)
cureModel(model)
These are not to be called by the user.