from random import random
import math
import sys
class SimAnneal(object):
def __init__(self, target_text='min'):
self.target_text = target_text
def newVar(self, oldList, T):
newList = [i + (random()*2-1) for i in oldList]
return newList
def juge(self, func, new, old, T):
dE = func(new) - func(old) if self.target_text == 'max' else func(old) - func(new)
if dE >= 0:
x, ans = new, func(new)
else:
if math.exp(dE/T) > random():
x, ans = new, func(new)
else:
x, ans = old, func(old)
return [x, ans]
class OptSolution(object):
def __init__(self, temperature0=100, temDelta=0.98, temFinal=1e-8, Markov_chain=2000, result=0, val_nd=[0]):
# initial temperature
self.temperature0 = temperature0
# step factor for decreasing temperature
self.temDelta = temDelta
# the final temperature
self.temFinal = temFinal
# the Markov_chain length (inner loops numbers)
self.Markov_chain = Markov_chain
# the final result
self.result = result
# the initial coordidate values: 1D [0], 2D [0,0] ...
self.val_nd = val_nd
def mapRange(self, oneDrange):
return (oneDrange[1]-oneDrange[0])*random() + oneDrange[0]
def soulution(self, SA_newV, SA_juge, juge_text, ValueRange, func):
Ti = self.temperature0
ndim = len(ValueRange)
f = max if juge_text == 'max' else min
loops = 0
while Ti > self.temFinal:
res_temp, val_temp = [], []
preV = [[self.mapRange(ValueRange[j]) for i in range(self.Markov_chain)] for j in range(ndim)]
newV = [SA_newV(preV[j], T=Ti) for j in range(ndim)]
for i in range(self.Markov_chain):
boolV = True
for j in range(ndim):
boolV &= (ValueRange[j][0] <= newV[j][i] <= ValueRange[j][1])
if boolV == True:
res_temp.append(SA_juge(new=[newV[k][i] for k in range(ndim)],
func=func,
old=[preV[k][i] for k in range(ndim)],
T=Ti)[-1])
val_temp.append(SA_juge(new=[newV[k][i] for k in range(ndim)],
func=func,
old=[preV[k][i] for k in range(ndim)],
T=Ti)[0])
else:
continue
loops += 1
# get the index of extreme value
idex = res_temp.index(f(res_temp))
result_temp = f(self.result, f(res_temp))
# update the cooordidate of current extrema value
self.val_nd = self.val_nd if result_temp == self.result else val_temp[idex]
# update the extreme value
self.result = result_temp
# update the current temperature
Ti *= self.temDelta
print(self.val_nd, self.result)
print(loops)
# print('The extreme value = %f' %self.result[-1])
