JobShopScheduling/src/SchedulingAlgorithms/simanneal.py

37 lines
1.2 KiB
Python

from Generator.generator import generate
from Generator.generator import init as gen_init
from SchedulingAlgorithms.enumerate import enumerate as enum
from math import e
from random import random
def anneal(max_temp = 1000, max_steps = 1000):
global problem
gen_init(problem)
temp = max_temp
initial = enum(problem)
current = generate(initial, problem.machines * problem.jobs * 10)
del initial
for step in range(0, max_steps):
new = generate(current, problem.machines * problem.jobs)
new_end = rate(new)
curr_end = rate(current)
p = 1 / ( 1 + (e ** ((curr_end - new_end)/temp)))
if (new_end < curr_end) or (p < random()):
current = new
print("Old: " + str(curr_end) + " New: " + str(new_end))
temp = ((max_temp-1)/(max_steps**2))*(step-max_steps)**2+1
print("Iteration: "+ str(step) + " Temperature: " + str(temp))
return current
def rate(solution):
global problem
last_tasks = []
for i in range(0,problem.jobs):
last_tasks += [next(( x for x in solution[::-1] if x[1][0] == i), [])]
end_times = [ problem[x[1]][0] + x[0] for x in last_tasks]
return max(end_times)
def init(in_problem):
global problem
problem = in_problem