NSGAII ValueError

[ghost]

Hi, I'm currently using Platypus' NSGA-II function and have been encountering a ValueError in core.py.

After an inconsistent number of iterations, it throws an error as the self.function(solution.variables) in core.py returns [False] rather than a pair of lists. I've used the same NSGA-II settings on another problem and I had no issues with it.

I've attached my NSGAII settings along with my traceback file and some sample values given by self.function(solution.variables).

Does anyone know what might be causing it to return such a value?

Thanks

problem = Problem(11, 8, 10)
problem.types[:] = [Real(0.01, 1.5), Real(0.05, 0.25), Real(0.01, 0.25), Real(1, 2), Real(0.03, 0.1), Real(1, 5), Real(3,5), Integer(0,12), Integer(0,9), Integer(1,2), Real(0.01,1)]
problem.constraints[:] = "<0"
problem.function = model

algorithm = NSGAII(problem,variator=CompoundOperator(SBX(), HUX(), PM(), BitFlip()))
algorithm.run(10000)

Traceback (most recent call last):

  File "C:\Users\Dennis\Desktop\New folder\model.py", line 606, in <module>
    algorithm.run(10000)

  File "C:\Users\Dennis\anaconda3\lib\site-packages\platypus\core.py", line 410, in run
    self.step()

  File "C:\Users\Dennis\anaconda3\lib\site-packages\platypus\algorithms.py", line 181, in step
    self.initialize()

  File "C:\Users\Dennis\anaconda3\lib\site-packages\platypus\algorithms.py", line 191, in initialize
    super(NSGAII, self).initialize()

  File "C:\Users\Dennis\anaconda3\lib\site-packages\platypus\algorithms.py", line 72, in initialize
    self.evaluate_all(self.population)

  File "C:\Users\Dennis\anaconda3\lib\site-packages\platypus\core.py", line 383, in evaluate_all
    results = self.evaluator.evaluate_all(jobs)

  File "C:\Users\Dennis\anaconda3\lib\site-packages\platypus\evaluator.py", line 88, in evaluate_all
    return list(self.map_func(run_job, jobs))

  File "C:\Users\Dennis\anaconda3\lib\site-packages\platypus\evaluator.py", line 55, in run_job
    job.run()

  File "C:\Users\Dennis\anaconda3\lib\site-packages\platypus\core.py", line 350, in run
    self.solution.evaluate()

  File "C:\Users\Dennis\anaconda3\lib\site-packages\platypus\core.py", line 523, in evaluate
    self.problem(self)

  File "C:\Users\Dennis\anaconda3\lib\site-packages\platypus\core.py", line 165, in __call__
    self.evaluate(solution)

  File "C:\Users\Dennis\anaconda3\lib\site-packages\platypus\core.py", line 191, in evaluate
    (objs, constrs) = self.function(solution.variables)

ValueError: not enough values to unpack (expected 2, got 1)

[[2.50861132238244, 0.3903417051679467, -0.543742035537466, 1.329871101621052, -0.20242039363804123, 6, 5.327322745957215, -0.543742035537466], [10.578699506953527, 2.2, -66.6, -0.06805097093184115, -6.292890004130986, -0.6055867104407471, -0.3944132895592529, 0.543742035537466, -1.329871101621052, -8.16714296906334]]
[[1.0317548868503343, 0.1925439466528248, 0.3021696588989762, 4.938305314218708, 0.763849125186179, 6, 2.669283067563014, 0.3021696588989762], [-20.00189874847675, -19.2, -99.90000000000002, -0.2037189971328583, -9.960316545202902, -0.42301898486518164, -0.5769810151348184, -0.3021696588989762, -4.938305314218708, -8.21550081925964]]
[False]

[jetuk]

This is caused by the function (in this case whatever model is) returning [False], and not a tuple.

[ghost]

Thanks, that appeared to be the case. Managed to solve the issue and everything works fine.

[github-actions[bot]]

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