SAMDE

Type to calibrate a model using genetic algorithm. It returns a SAMDE type with the fittest individual (a Model), its fit value, and the number of generations taken by the genetic algorithm to reach the result. SaMDE paper is available at: ( https://onedrive.live.com/redir?resid=50A40B914086BD50!4054&authkey=!ACNH3WpLEBuIOME&ithint=file%2cpdf ).

Arguments

• fit: A user-defined function that gets a model instance as argument and returns a numeric value of that particular model fitness, this value will be minimized or maximized by SAMDE according to the maximize parameter.
• maxGen: The maximum number of generations. If the simulation reaches this value, it stops and returns the Model that has the fittest result? TODO.
• maximize: An optional paramaters that determines if the fit will be maximized (true) or minimized (false, default value).
• model: A Model.
• parameters: A table with the possible parameter values. They can be values or Choices. All Choices will be calibrated.
• size: The maximum population size in each generation.
• threshold: If the fitness of a model reaches this value, SAMDE stops and returns such model.

Attributes

Some attributes of SAMDE have internal semantics. They can be used as read-only by the modeler.

• fit: The best fitness result returned by the SAMDE Algorithm.
• generation: The number of generations created by the generit algorithm until it stopped.
• instance: The instance of the model with the best fitness.

Usage

import("calibration")
local MyModel = Model{
  x = Choice{min = -100, max = 100},
  y = Choice{min = 1, max = 10},
  finalTime = 1,
  init = function(self)
    self.timer = Timer{
      Event{action = function()
        self.value = 2 * self.x ^2 - 3 * self.x + 4 + self.y
      end}
  }
  end
}
c = SAMDE{
    model = MyModel,
    parameters = {x = Choice{min = -100, max = 100}, y = Choice {min = 1, max = 10}, finalTime = 1},
    fit = function(model)
        return model.value
    end
}