Idyll on Rails

class Person extends IdyllModel
    belongs_to :working_population

    define_attribute :stress, type: integer, min: 0, max: 100, init: random
    define_attribute :environment, type: enum, ['high income', 'low income', 'normal']
    define_attribute :group, type: classification, |model| => { case model.stress; when 50..100: "high risk"; when 0..49: "low risk" }

    def next_step
        self.stress += 5 if self.environment == "high income"
        self.stress -= 5 if self.environment == "low income"
    end 
end

class WorkingPopulation extends IdyllPopulation
    populate_with :persons, amount: 100
    is_step_function step_unit: "years"

    def next_step
        persons.each do |p| 
            p.environment = "normal" if chance(.03)
            p.environment = "high income" if chance(.01)
        end 
    end 
end 

@base_model = new WorkingPopulation()
@base_model.render