使用鸭嘴兽 (Python) 进行整数、多目标优化

Question

我正在探索Platypus 库以在 Python 中进行多目标优化。在我看来，Platypus 应该支持开箱即用的整数变量（优化参数），但是这个简单的问题（两个目标，三个变量，无约束和 SMPSO 的整数变量）：

from platypus import *

def my_function(x):
    """ Some objective function"""
    return [-x[0] ** 2 - x[2] ** 2, x[1] - x[0]]

def AsInteger():

    problem = Problem(3, 2)  # define 3 inputs and 1 objective (and no constraints)
    problem.directions[:] = Problem.MAXIMIZE
    int1 = Integer(-50, 50)
    int2 = Integer(-50, 50)
    int3 = Integer(-50, 50)
    problem.types[:] = [int1, int2, int3]
    problem.function = my_function
    algorithm = SMPSO(problem)
    algorithm.run(10000)

结果成：

Traceback (most recent call last):
File "D:\MyProjects\Drilling\test_platypus.py", line 62, in 
AsInteger()
File "D:\MyProjects\Drilling\test_platypus.py", line 19, in AsInteger
algorithm.run(10000)
File "build\bdist.win-amd64\egg\platypus\core.py", line 405, in run
File "build\bdist.win-amd64\egg\platypus\algorithms.py", line 820, in step
File "build\bdist.win-amd64\egg\platypus\algorithms.py", line 838, in iterate
File "build\bdist.win-amd64\egg\platypus\algorithms.py", line 1008, in _update_velocities
TypeError: unsupported operand type(s) for -: 'list' and 'list'

同样，如果我尝试在 Platypus 中使用另一种优化技术（CMAES 而不是 SMPSO）：

Traceback (most recent call last):
File "D:\MyProjects\Drilling\test_platypus.py", line 62, in 
AsInteger()
File "D:\MyProjects\Drilling\test_platypus.py", line 19, in AsInteger
algorithm.run(10000)
File "build\bdist.win-amd64\egg\platypus\core.py", line 405, in run
File "build\bdist.win-amd64\egg\platypus\algorithms.py", line 1074, in step
File "build\bdist.win-amd64\egg\platypus\algorithms.py", line 1134, in initialize
File "build\bdist.win-amd64\egg\platypus\algorithms.py", line 1298, in iterate
File "build\bdist.win-amd64\egg\platypus\core.py", line 378, in evaluate_all
File "build\bdist.win-amd64\egg\platypus\evaluator.py", line 88, in evaluate_all
File "build\bdist.win-amd64\egg\platypus\evaluator.py", line 55, in run_job
File "build\bdist.win-amd64\egg\platypus\core.py", line 345, in run
File "build\bdist.win-amd64\egg\platypus\core.py", line 518, in evaluate
File "build\bdist.win-amd64\egg\platypus\core.py", line 160, in call
File "build\bdist.win-amd64\egg\platypus\types.py", line 147, in decode

File "build\bdist.win-amd64\egg\platypus\tools.py", line 521, in gray2bin
TypeError: 'float' object has no attribute 'getitem'

我使用其他算法（OMOPSO、GDE3）收到其他类型的错误消息。虽然 NSGAIII、NSGAII、SPEA2 等算法似乎正在运行。

有没有人遇到过这样的问题？也许我以错误的方式指定问题？

提前感谢您的任何建议。

安德烈亚。

Answer 1

尝试改变你添加问题类型的方式

problem.types[:] = [integer(-50,50),integer(-50,50),integer(-50,50)]

可以这样工作