Python演化計算基準函數詳解
基準函數是測試演化計算算法性能的函數集,由於大部分基準函數集都是C/C++編寫,Python編寫的基準函數比較少,因此本文實現瞭13個常用基準函數的Python版。
基準函數定義
代碼實現
benchmark.py
import numpy as np import copy """ Author : Robin_Hua update time : 2021.10.14 version : 1.0 """ class Sphere: def __init__(self, x): self.x = x def getvalue(self): res = np.sum(self.x**2) return res class Schwefel2_22: def __init__(self, x): self.x = x def getvalue(self): res = np.sum(np.abs(self.x)) + np.prod(np.abs(self.x)) return res class Noise: def __init__(self,x): self.x = x def getvalue(self): d = self.x.shape[0] res = np.sum(np.arange(1, d + 1) * self.x ** 4) + np.random.random() return res class Schwefel2_21: def __init__(self,x): self.x = x def getvalue(self): res = np.max(np.abs(self.x)) return res class Step: def __init__(self,x): self.x = x def getvalue(self): res = np.sum(int(self.x + 0.5) ** 2) return res class Rosenbrock: def __init__(self,x): self.x = x def getvalue(self): d = self.x.shape[0] res = np.sum(np.abs(100*(self.x[1:] - self.x[:-1]**2)**2 + (1 - self.x[:-1])**2)) return res class Schwefel: def __init__(self,x): self.x = x def getvalue(self): d = self.x.shape[0] res = 418.9829*d - np.sum(self.x * np.sin(np.sqrt(np.abs(self.x)))) return res class Rastrigin: def __init__(self,x): self.x = x def getvalue(self): d = self.x.shape[0] res = 10 * d + np.sum(self.x ** 2 - 10 * np.cos(2 * np.pi * self.x)) return res class Ackley: def __init__(self,x): self.x = x def getvalue(self): d = self.x.shape[0] res = - 20 * np.exp(-0.2 * np.sqrt(np.mean(self.x ** 2))) res = res - np.exp(np.mean(np.cos(2 * np.pi * self.x))) + 20 + np.exp(1) return res class Griewank: def __init__(self,x): self.x = x def getvalue(self): d = self.x.shape[0] i = np.arange(1, d + 1) res = 1 + np.sum(self.x ** 2) / 4000 - np.prod(np.cos(self.x / np.sqrt(i))) return res class Generalized_Penalized: def __init__(self,x): self.x = x def u(self,a,k,m): temp = copy.deepcopy(self.x) temp[-a <= temp.any() <= a] = 0 temp[temp > a] = k*(temp[temp > a]-a)**m temp[temp < -a] = k * (-temp[temp < -a] - a) ** m """ temp = np.zeros_like(self.x) d = self.x.shape[0] for i in range(d): if self.x[i]>a: temp[i] = k*(self.x[i]-a)**m elif self.x[i]<-a: temp[i] = k * (-self.x[i] - a) ** m else: pass """ return temp def getvalue(self): d = self.x.shape[0] y = 1+1/4*(self.x+1) res = np.pi/d*(10*np.sin(np.pi*y[0])**2+np.sum((y[:-1]-1)**2*(1+10*np.sin(np.pi*y[1:])**2))+(y[-1]-1)**2)+np.sum(self.u(10,100,4)) return res def benchmark_func(x,func_num): func = func_list[func_num] res = func(x) return res func_list = [Sphere,Schwefel2_22,Noise,Schwefel2_21,Step,Rosenbrock,Schwefel,Rastrigin,Ackley,Griewank,Generalized_Penalized]
調用方法
輸入為向量x和函數編號func_num
import benchmark import numpy as np vector = np.random.random(30) value = benchmark.benchmark_func(x=vector,func_num=0).getvalue()
總結
本篇文章就到這裡瞭,希望能夠給你帶來幫助,也希望您能夠多多關註WalkonNet的更多內容!
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