import numpy as np
from iOpt.trial import Point
from iOpt.trial import FunctionValue
from iOpt.trial import Trial
from iOpt.problem import Problem
import problems.Hill.hill_generation as hillGen
import math
[документация]class Hill(Problem):
"""
The Hill function is a multimodal, continuous, deterministic function, given by the formula:
:math:`f(x)=a_{0}+\sum_{i=1}^{m}(a_{i}sin(2i\pi x)+b_{i}cos(2i\pi x))`,
where :math:`m` is the number of maxima of the function,
:math:`a, b` - parameters generated randomly.
In this generator the problem is one-dimensional.
"""
[документация] def __init__(self, function_number: int):
"""
Constructor of the Hill problem class
:param functionNumber: task number in the set, :math:`1 <= functionNumber <= 1000`
"""
super(Hill, self).__init__()
self.name = "Hill"
self.dimension = 1
self.number_of_float_variables = self.dimension
self.number_of_discrete_variables = 0
self.number_of_objectives = 1
self.number_of_constraints = 0
self.fn = function_number
self.float_variable_names = np.ndarray(shape=(self.dimension), dtype=str)
for i in range(self.dimension):
self.float_variable_names[i] = i
self.lower_bound_of_float_variables = np.ndarray(shape=(self.dimension), dtype=np.double)
self.lower_bound_of_float_variables.fill(0)
self.upper_bound_of_float_variables = np.ndarray(shape=(self.dimension), dtype=np.double)
self.upper_bound_of_float_variables.fill(1)
self.known_optimum = np.ndarray(shape=(1), dtype=Trial)
pointfv = np.ndarray(shape=(self.dimension), dtype=np.double)
pointfv[0] = hillGen.minHill[self.fn][1]
KOpoint = Point(pointfv, [])
KOfunV = np.ndarray(shape=(1), dtype=FunctionValue)
KOfunV[0] = FunctionValue()
KOfunV[0].value = hillGen.minHill[self.fn][0]
self.known_optimum[0] = Trial(KOpoint, KOfunV)
[документация] def calculate(self, point: Point, function_value: FunctionValue) -> FunctionValue:
"""
Calculate the value of the selected function at a given point
:param point: coordinates of the trial point where the value of the function will be calculated.
:param function_value: object defining the function number in the task and storing the function value.
:return: Calculated value of the function at point.
"""
res: np.double = 0
for i in range(hillGen.NUM_HILL_COEFF):
res = res + hillGen.aHill[self.fn][i] * math.sin(2 * i * math.pi * point.float_variables[0]) + \
hillGen.bHill[self.fn][i] * math.cos(2 * i * math.pi * point.float_variables[0])
function_value.value = res
return function_value