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jMetal / jMetalPy

A framework for single/multi-objective optimization with metaheuristics
https://jmetal.github.io/jMetalPy/index.html
MIT License
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Question about function evaluations #150

Closed mich0611 closed 1 year ago

mich0611 commented 1 year ago

I'm not sure about how to count the function evaluations for MOEAs. In NSGAII, the function evaluations seems to be dependent on the population size. (self.evaluations += self.offspring_population_size). So my question is : the function evaluations have nothing to do with the objective number, or something else in the algorithm ? Thank you!

ajnebro commented 1 year ago

Hi. The number of funtion evaluations counts the number of times that the functions of a problem are evaluated. It does not take into accout that a problem could have 1, 2 or more objectives.

In a generational GA, both the population and the offpspring population have the same size, but in a steady-state one the size of the offspring population size is one. As the new generated solutions are those in the offpspring population, the evaluation counter is increased by the offpspring population size.