A Simulation is basically the OpenFisca frame for calculating taxes or benefits.
To calculate any variable you need to create a Simulation from the TaxBenefitSystem that is to say the framework where you will compute your result.
Technically speaking it is the cache of input data and previously computed results.
It’s possible to run many independent simulations using the same TaxBenefitSystem.
To compute taxes and benefits, you need to define on whom you want to do that and what you already know about those persons or groups of persons. This is what you will set as input data for your Simulation.
Then, be aware of the period over which you want to have your result. Some measures are calculated on a monthly basis other an annual one.
Now all the settings are given to run computation of taxes or benefits.
For further information: see how to run a simulation in this section and the following tutorial “How to handle periods”
# Calcul of the 'impot sur le revenu des personnes physiques'
impot = simulation.calculate('irpp', '2015')
allocations_familiales = simulation.calculate('af', '2015-01')
HINT: Don’t forget to give the period.
The output is an array:
positive if it is an amount the entity receives from the state.
negative if it is an amount the entity has to pay.