When there are covariates on the Rhs , in the preceding becomes x where x is the covariate vector, including ONE . The options for the loglinear survival models are the usual ones for nonlinear models. You may provide your own starting values for the models if you wish. In the exponential model, F equals 1, so you should not include it in the list. You can also set the maximum to 0 to compute a Lagrange multiplier statistic if you provide your own starting values.
All algorithms are available.
For all models except the gamma model, Newton's method is available using an actual Hessian.