Regarding the data_simulation.Rmd file

[zhiiiyang]

Hi, I have a few thoughts about improving the vignette data_simulation.Rmd file for your consideration.

• [ ] add some texts to explain how to convert median survival time to lambda in the create_event_dist function. It would be something like lambda is equal to log(2)/median survival time, e.g., if survival time is equal to 24 months, lambda is set to be log(2)/24. https://github.com/Genentech/psborrow2/blob/5123a8c6149ced68e09abc7cfd47ca4077de8f5e/vignettes/data_simulation.Rmd#L213

• [ ] remove the lines associated with external control in the section " Using fixed external data" https://github.com/Genentech/psborrow2/blob/5123a8c6149ced68e09abc7cfd47ca4077de8f5e/vignettes/data_simulation.Rmd#L582-L600

• [ ] only count the number of events for cut_off_after_events described in https://github.com/Genentech/psborrow2/issues/279 https://github.com/Genentech/psborrow2/blob/5123a8c6149ced68e09abc7cfd47ca4077de8f5e/R/simulate_data.R#L328

• Using a cutoff value to dichotomize a continuous variable to a binary variable is not needed since it is pretty straightforward for users to do it instead.

• I just noticed that you have introduced enrollment_constant function in earlier sections so I think the additional texts are not needed then.