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# encoding=utf8 |
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import logging |
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import numpy as np |
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from NiaPy.algorithms.algorithm import Algorithm |
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logging.basicConfig() |
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logger = logging.getLogger('NiaPy.algorithms.other') |
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logger.setLevel('INFO') |
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__all__ = ['RandomSearch'] |
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class RandomSearch(Algorithm): |
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r"""Implementation of a simple Random Algorithm. |
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Algorithm: |
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Random Search |
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Date: |
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11.10.2020 |
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Authors: |
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Iztok Fister Jr., Grega Vrbančič |
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License: |
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MIT |
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Reference URL: https://en.wikipedia.org/wiki/Random_search |
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Attributes: |
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Name (List[str]): List of strings representing algorithm name. |
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See Also: |
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* :class:`NiaPy.algorithms.Algorithm` |
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""" |
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Name = ['RandomSearch', 'RS'] |
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@staticmethod |
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def algorithmInfo(): |
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r"""Get basic information of algorithm. |
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Returns: |
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str: Basic information of algorithm. |
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See Also: |
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* :func:`NiaPy.algorithms.Algorithm.algorithmInfo` |
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""" |
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return r"""None""" |
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def setParameters(self): |
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r"""Set the algorithm parameters/arguments. |
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Arguments: |
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See Also |
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* :func:`NiaPy.algorithms.Algorithm.setParameters` |
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""" |
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Algorithm.setParameters(self, NP=1) |
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def getParameters(self): |
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r"""Get algorithms parametes values. |
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Returns: |
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Dict[str, Any]: |
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See Also |
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* :func:`NiaPy.algorithms.Algorithm.getParameters` |
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""" |
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d = Algorithm.getParameters(self) |
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return d |
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def initPopulation(self, task): |
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r"""Initialize the starting population. |
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Args: |
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task (Task): Optimization task. |
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Returns: |
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Tuple[numpy.ndarray, float, dict]: |
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1. Initial solution |
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2. Initial solutions fitness/objective value |
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3. Additional arguments |
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""" |
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total_candidates = 0 |
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if task.nGEN or task.nFES: |
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total_candidates = task.nGEN if task.nGEN else task.nFES |
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self.candidates = [] |
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for i in range(total_candidates): |
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while True: |
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x = task.Lower + task.bcRange() * self.rand(task.D) |
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if not np.any([np.all(a == x) for a in self.candidates]): |
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self.candidates.append(x) |
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break |
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xfit = task.eval(self.candidates[0]) |
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return x, xfit, {} |
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def runIteration(self, task, x, xfit, xb, fxb, **dparams): |
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r"""Core function of the algorithm. |
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Args: |
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task (Task): |
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x (numpy.ndarray): |
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xfit (float): |
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xb (numpy.ndarray): |
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fxb (float): |
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**dparams (dict): Additional arguments. |
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Returns: |
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Tuple[numpy.ndarray, float, numpy.ndarray, float, dict]: |
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1. New solution |
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2. New solutions fitness/objective value |
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3. New global best solution |
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4. New global best solutions fitness/objective value |
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5. Additional arguments |
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""" |
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current_candidate = task.Evals if task.Evals else task.Iters |
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x = self.candidates[current_candidate] |
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xfit = task.eval(x) |
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xb, fxb = self.getBest(x, xfit, xb, fxb) |
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return x, xfit, xb, fxb, {} |
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