min_E_SS_power_constraints: Sample objective function to minimize
In aaronjfisher/designOptim: Design optimizer

optimizeTrial requires users to input an objective function to evaluate the trial design in each case. min_E_SS_power_constraints is a pre-set option for an objective function based on expected sample size. min_E_dur_power_constraints is a pre-set option for an objective function based on expected duration. Both functions' output a list including a penalized objective function value. Any custom objective function supplied to optimizeTrial must be able to run in the context of the get_case_perf_obj function, and give output in the same format as that of the functions below.

1
2
3

min_E_SS_power_constraints(...)

min_E_dur_power_constraints(...)

...

for internal use.

a list containing

`base`	the expected sample size, or expected duration
`penalized`	the value of `base` plus a penalty if any of the power constraints are violated
`power_diffs`	a matrix showing the difference between achieved power and required power for each case, and each constraint.