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# encoding=utf8 |
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"""The implementation of tasks.""" |
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import logging |
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from enum import Enum |
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from matplotlib import pyplot as plt |
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from numpy import inf, random as rand |
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from NiaPy.util.utility import ( |
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limit_repair, |
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fullArray |
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) |
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from NiaPy.util.exception import ( |
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FesException, |
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GenException, |
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RefException |
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) |
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from NiaPy.task.utility import Utility |
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logging.basicConfig() |
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logger = logging.getLogger("NiaPy.task.Task") |
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logger.setLevel("INFO") |
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class OptimizationType(Enum): |
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r"""Enum representing type of optimization. |
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Attributes: |
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MINIMIZATION (int): Represents minimization problems and is default optimization type of all algorithms. |
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MAXIMIZATION (int): Represents maximization problems. |
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""" |
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MINIMIZATION = 1.0 |
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MAXIMIZATION = -1.0 |
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class Task: |
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r"""Class representing problem to solve with optimization. |
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Date: |
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2019 |
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Author: |
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Klemen Berkovič and others |
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Attributes: |
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D (int): Dimension of the problem. |
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Lower (numpy.ndarray): Lower bounds of the problem. |
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Upper (numpy.ndarray): Upper bounds of the problem. |
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bRange (numpy.ndarray): Search range between upper and lower limits. |
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optType (OptimizationType): Optimization type to use. |
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See Also: |
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* :class:`NiaPy.util.Utility` |
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""" |
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D = 0 |
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benchmark = None |
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Lower, Upper, bRange = inf, inf, inf |
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optType = OptimizationType.MINIMIZATION |
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def __init__(self, D=0, optType=OptimizationType.MINIMIZATION, benchmark=None, Lower=None, Upper=None, frepair=limit_repair, **kwargs): |
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r"""Initialize task class for optimization. |
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Arguments: |
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D (Optional[int]): Number of dimensions. |
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optType (Optional[OptimizationType]): Set the type of optimization. |
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benchmark (Union[str, Benchmark]): Problem to solve with optimization. |
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Lower (Optional[numpy.ndarray]): Lower limits of the problem. |
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Upper (Optional[numpy.ndarray]): Upper limits of the problem. |
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frepair (Optional[Callable[[numpy.ndarray, numpy.ndarray, numpy.ndarray, Dict[str, Any]], numpy.ndarray]]): Function for reparing individuals components to desired limits. |
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See Also: |
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* `func`:NiaPy.util.Utility.__init__` |
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* `func`:NiaPy.util.Utility.repair` |
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""" |
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# dimension of the problem |
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self.D = D |
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# set optimization type |
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self.optType = optType |
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# set optimization function |
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self.benchmark = Utility().get_benchmark(benchmark) if benchmark is not None else None |
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if self.benchmark is not None: |
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self.Fun = self.benchmark.function() if self.benchmark is not None else None |
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# set Lower limits |
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if Lower is not None: |
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self.Lower = fullArray(Lower, self.D) |
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elif Lower is None and benchmark is not None: |
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self.Lower = fullArray(self.benchmark.Lower, self.D) |
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else: |
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self.Lower = fullArray(0, self.D) |
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# set Upper limits |
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if Upper is not None: |
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self.Upper = fullArray(Upper, self.D) |
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elif Upper is None and benchmark is not None: |
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self.Upper = fullArray(self.benchmark.Upper, self.D) |
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else: |
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self.Upper = fullArray(0, self.D) |
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# set range |
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self.bRange = self.Upper - self.Lower |
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# set repair function |
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self.frepair = frepair |
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def dim(self): |
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r"""Get the number of dimensions. |
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Returns: |
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int: Dimension of problem optimizing. |
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""" |
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return self.D |
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def bcLower(self): |
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r"""Get the array of lower bound constraint. |
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Returns: |
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numpy.ndarray: Lower bound. |
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""" |
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return self.Lower |
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def bcUpper(self): |
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r"""Get the array of upper bound constraint. |
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Returns: |
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numpy.ndarray: Upper bound. |
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""" |
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return self.Upper |
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def bcRange(self): |
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r"""Get the range of bound constraint. |
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Returns: |
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numpy.ndarray: Range between lower and upper bound. |
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""" |
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return self.Upper - self.Lower |
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def repair(self, x, rnd=rand): |
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r"""Repair solution and put the solution in the random position inside of the bounds of problem. |
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Arguments: |
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x (numpy.ndarray): Solution to check and repair if needed. |
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rnd (mtrand.RandomState): Random number generator. |
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Returns: |
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numpy.ndarray: Fixed solution. |
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See Also: |
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* :func:`NiaPy.util.limitRepair` |
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* :func:`NiaPy.util.limitInversRepair` |
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* :func:`NiaPy.util.wangRepair` |
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* :func:`NiaPy.util.randRepair` |
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* :func:`NiaPy.util.reflectRepair` |
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""" |
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return self.frepair(x, self.Lower, self.Upper, rnd=rnd) |
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def nextIter(self): |
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r"""Increments the number of algorithm iterations.""" |
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def start(self): |
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r"""Start stopwatch.""" |
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def eval(self, A): |
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r"""Evaluate the solution A. |
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Arguments: |
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A (numpy.ndarray): Solution to evaluate. |
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Returns: |
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float: Fitness/function values of solution. |
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""" |
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return self.Fun(self.D, A) * self.optType.value |
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def isFeasible(self, A): |
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r"""Check if the solution is feasible. |
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Arguments: |
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A (Union[numpy.ndarray, Individual]): Solution to check for feasibility. |
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Returns: |
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bool: `True` if solution is in feasible space else `False`. |
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""" |
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return False not in (A >= self.Lower) and False not in (A <= self.Upper) |
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def stopCond(self): |
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r"""Check if optimization task should stop. |
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Returns: |
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bool: `True` if stopping condition is meet else `False`. |
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""" |
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return False |
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class CountingTask(Task): |
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r"""Optimization task with added counting of function evaluations and algorithm iterations/generations. |
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Attributes: |
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Iters (int): Number of algorithm iterations/generations. |
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Evals (int): Number of function evaluations. |
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See Also: |
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* :class:`NiaPy.util.Task` |
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""" |
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def __init__(self, **kwargs): |
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r"""Initialize counting task. |
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Args: |
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**kwargs (Dict[str, Any]): Additional arguments. |
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See Also: |
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* :func:`NiaPy.util.Task.__init__` |
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""" |
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Task.__init__(self, **kwargs) |
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self.Iters, self.Evals = 0, 0 |
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def eval(self, A): |
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r"""Evaluate the solution A. |
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This function increments function evaluation counter `self.Evals`. |
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Arguments: |
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A (numpy.ndarray): Solutions to evaluate. |
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Returns: |
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float: Fitness/function values of solution. |
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See Also: |
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* :func:`NiaPy.util.Task.eval` |
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""" |
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r = Task.eval(self, A) |
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self.Evals += 1 |
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return r |
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def evals(self): |
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r"""Get the number of evaluations made. |
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Returns: |
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int: Number of evaluations made. |
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""" |
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return self.Evals |
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def iters(self): |
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r"""Get the number of algorithm iteratins made. |
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Returns: |
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int: Number of generations/iterations made by algorithm. |
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""" |
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return self.Iters |
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def nextIter(self): |
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r"""Increases the number of algorithm iterations made. |
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This function increments number of algorithm iterations/generations counter `self.Iters`. |
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""" |
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self.Iters += 1 |
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class StoppingTask(CountingTask): |
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r"""Optimization task with implemented checking for stopping criterias. |
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Attributes: |
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nGEN (int): Maximum number of algorithm iterations/generations. |
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nFES (int): Maximum number of function evaluations. |
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refValue (float): Reference function/fitness values to reach in optimization. |
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x (numpy.ndarray): Best found individual. |
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x_f (float): Best found individual function/fitness value. |
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See Also: |
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* :class:`NiaPy.util.CountingTask` |
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""" |
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def __init__(self, nFES=inf, nGEN=inf, refValue=None, logger=False, **kwargs): |
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r"""Initialize task class for optimization. |
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Arguments: |
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nFES (Optional[int]): Number of function evaluations. |
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nGEN (Optional[int]): Number of generations or iterations. |
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refValue (Optional[float]): Reference value of function/fitness function. |
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logger (Optional[bool]): Enable/disable logging of improvements. |
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Note: |
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Storing improvements during the evolutionary cycle is |
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captured in self.n_evals and self.x_f_vals |
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See Also: |
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* :func:`NiaPy.util.CountingTask.__init__` |
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""" |
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CountingTask.__init__(self, **kwargs) |
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self.refValue = (-inf if refValue is None else refValue) |
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self.logger = logger |
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self.x, self.x_f = None, inf |
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self.nFES, self.nGEN = nFES, nGEN |
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self.n_evals = [] |
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self.x_f_vals = [] |
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def eval(self, A): |
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r"""Evaluate solution. |
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Args: |
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A (numpy.ndarray): Solution to evaluate. |
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Returns: |
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float: Fitness/function value of solution. |
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See Also: |
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* :func:`NiaPy.util.StoppingTask.stopCond` |
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* :func:`NiaPy.util.CountingTask.eval` |
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""" |
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if self.stopCond(): |
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return inf * self.optType.value |
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x_f = CountingTask.eval(self, A) |
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if x_f < self.x_f: |
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self.x_f = x_f |
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self.n_evals.append(self.Evals) |
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self.x_f_vals.append(x_f) |
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if self.logger: |
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logger.info('nFES:%d => %s' % (self.Evals, self.x_f)) |
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return x_f |
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def stopCond(self): |
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r"""Check if stopping condition reached. |
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Returns: |
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bool: `True` if number of function evaluations or number of algorithm iterations/generations or reference values is reach else `False`. |
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""" |
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return (self.Evals >= self.nFES) or (self.Iters >= self.nGEN) or (self.refValue > self.x_f) |
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def stopCondI(self): |
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r"""Check if stopping condition reached and increase number of iterations. |
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Returns: |
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bool: `True` if number of function evaluations or number of algorithm iterations/generations or reference values is reach else `False`. |
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See Also: |
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* :func:`NiaPy.util.StoppingTask.stopCond` |
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* :func:`NiaPy.util.CountingTask.nextIter` |
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""" |
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r = self.stopCond() |
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CountingTask.nextIter(self) |
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return r |
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def return_conv(self): |
392
|
|
|
r"""Get values of x and y axis for plotting covariance graph. |
393
|
|
|
|
394
|
|
|
Returns: |
395
|
|
|
Tuple[List[int], List[float]]: |
396
|
|
|
1. List of ints of function evaluations. |
397
|
|
|
2. List of ints of function/fitness values. |
398
|
|
|
|
399
|
|
|
""" |
400
|
|
|
r1, r2 = [], [] |
401
|
|
|
for i, v in enumerate(self.n_evals): |
402
|
|
|
r1.append(v), r2.append(self.x_f_vals[i]) |
403
|
|
|
if i >= len(self.n_evals) - 1: break |
404
|
|
|
diff = self.n_evals[i + 1] - v |
405
|
|
|
if diff <= 1: continue |
406
|
|
|
for j in range(diff - 1): r1.append(v + j + 1), r2.append(self.x_f_vals[i]) |
407
|
|
|
return r1, r2 |
408
|
|
|
|
409
|
|
|
def plot(self): |
410
|
|
|
"""Plot a simple convergence graph.""" |
411
|
|
|
fess, fitnesses = self.return_conv() |
412
|
|
|
plt.plot(fess, fitnesses) |
413
|
|
|
plt.xlabel('nFes') |
414
|
|
|
plt.ylabel('Fitness') |
415
|
|
|
plt.title('Convergence graph') |
416
|
|
|
plt.show() |
417
|
|
|
|
418
|
|
|
|
419
|
|
|
class ThrowingTask(StoppingTask): |
420
|
|
|
r"""Task that throw exceptions when stopping condition is meet. |
421
|
|
|
|
422
|
|
|
See Also: |
423
|
|
|
* :class:`NiaPy.util.StoppingTask` |
424
|
|
|
|
425
|
|
|
""" |
426
|
|
|
|
427
|
|
|
def __init__(self, **kwargs): |
428
|
|
|
r"""Initialize optimization task. |
429
|
|
|
|
430
|
|
|
Args: |
431
|
|
|
**kwargs (Dict[str, Any]): Additional arguments. |
432
|
|
|
|
433
|
|
|
See Also: |
434
|
|
|
* :func:`NiaPy.util.StoppingTask.__init__` |
435
|
|
|
|
436
|
|
|
""" |
437
|
|
|
|
438
|
|
|
StoppingTask.__init__(self, **kwargs) |
439
|
|
|
|
440
|
|
|
def stopCondE(self): |
441
|
|
|
r"""Throw exception for the given stopping condition. |
442
|
|
|
|
443
|
|
|
Raises: |
444
|
|
|
* FesException: Thrown when the number of function/fitness evaluations is reached. |
445
|
|
|
* GenException: Thrown when the number of algorithms generations/iterations is reached. |
446
|
|
|
* RefException: Thrown when the reference values is reached. |
447
|
|
|
* TimeException: Thrown when algorithm exceeds time run limit. |
448
|
|
|
|
449
|
|
|
""" |
450
|
|
|
|
451
|
|
|
# dtime = datetime.now() - self.startTime |
452
|
|
|
if self.Evals >= self.nFES: |
453
|
|
|
raise FesException() |
454
|
|
|
if self.Iters >= self.nGEN: |
455
|
|
|
raise GenException() |
456
|
|
|
# if self.runTime is not None and self.runTime >= dtime: raise TimeException() |
457
|
|
|
if self.refValue >= self.x_f: |
458
|
|
|
raise RefException() |
459
|
|
|
|
460
|
|
|
def eval(self, A): |
461
|
|
|
r"""Evaluate solution. |
462
|
|
|
|
463
|
|
|
Args: |
464
|
|
|
A (numpy.ndarray): Solution to evaluate. |
465
|
|
|
|
466
|
|
|
Returns: |
467
|
|
|
float: Function/fitness values of solution. |
468
|
|
|
|
469
|
|
|
See Also: |
470
|
|
|
* :func:`NiaPy.util.ThrowingTask.stopCondE` |
471
|
|
|
* :func:`NiaPy.util.StoppingTask.eval` |
472
|
|
|
|
473
|
|
|
""" |
474
|
|
|
|
475
|
|
|
self.stopCondE() |
476
|
|
|
return StoppingTask.eval(self, A) |
477
|
|
|
|