4.4. discounting module

discounting.discount_values(settings, dict_of_values, program, arg)

The discount function determines metrics appropriate for discounting (those contained in dict_of_values) and does the discounting calculation to a given year and point within that year.

Parameters:

settings: The SetInputs class.

dict_of_values: Dictionary; provides values to be discounted with keys consisting of vehicle, model_year, age_id and discount rate.

program: String; indicates what program is being passed. arg: String; indicates whether totals or averages are being discounted.

Returns:

The passed dictionary with new key, value pairs where keys stipulate the discount rate and monetized values are discounted at the same rate as the discount rate of the input stream of values.

Note:

The costs_start entry of the BCA_General_Inputs file should be set to ‘start-year’ or ‘end-year’, where start-year represents costs starting at time t=0 (i.e., first year costs are undiscounted), and end-year represents costs starting at time t=1 (i.e., first year costs are discounted).