event-based simulator improvements

[mikkokotila]

Blocking use

• [x] doubles_in_days must follow logic where user is giving number of days during which doubling happens, and then this is applied each hour or day according to the input (note that doubles in 4 days is different than 1.25x growth factor daily)
• [x] hours_in_day should be hard coded, and not input parameter
  • [x] strictly follow the logic presented in here
  • [x] strictly follow the capacity process presented in here
  • [x] strictly follow the variable names in here
• [x] structure the simulation as a function that accepts as parameters all the parameters in here
• [x] remove all print outs
• [x] the function returns the object with the daily statistics
• [x] strictly follow pep8 styleguide
• [x] particularly you must pay attention to the cases when code on a single line is long, break it into separate lines, for example:

if you have:

place_available = (hospital.departments_capacity[icu_type]['max_capacity'] - len(
    hospital.departments_capacity[icu_type]['icu_date_arriving_list']))

you must make it instead:

_max_capacity_ = hospital.departments_capacity[icu_type]['max_capacity']
_new_cases_ = len(hospital.departments_capacity[icu_type]['icu_date_arriving_list'])

place_available = _max_capacity_ - _new_cases_

Note that temp variables can start with and end with to make it clear they are merely temp variables to keep code clean. Also they must use names that make it completely clear what those variables are. Each line of the code should be completely clear to read.

Improvements

DO NOT spend time with these before we have rolled-out a usable version as per above.

• [ ] make everything hour based, but report daily based