来自伪代码的 Java 模拟退火
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Java Simulated Annealing from Pseudocode
提问by Mus
I am currently working on a project (TSP) and am attempting to convert some simulated annealing pseudocode into Java. I have been successful in the past at converting pseudocode into Java code, however I am unable to convert this successfully.
我目前正在研究一个项目 (TSP)，并试图将一些模拟退火伪代码转换为 Java。过去我成功地将伪代码转换为 Java 代码，但是我无法成功转换。
The pseudocode is:
伪代码是：
T0(T and a lowercase 0) Starting temperature
Iter Number of iterations
λ The cooling rate
1. Set T = T0 (T and a lowercase 0)
2. Let x = a random solution
3. For i = 0 to Iter-1
4. Let f = fitness of x
5. Make a small change to x to make x'
6. Let f' = fitness of new point
7. If f' is worse than f then
8. Let p = PR(f', f, Ti (T with a lowercase i))
9. If p > UR(0,1) then
10. Undo change (x and f)
11. Else
12. Let x = x'
13. End if
14. Let Ti(T with a lowercase i) + 1 = λTi(λ and T with a lowercase i)
15. End for
Output: The solution x
If somebody could show me a basic mark-up of this in Java I would be extremely grateful - I just can't seem to figure it out!
如果有人能用 Java 向我展示这个的基本标记，我将非常感激 - 我似乎无法弄清楚！
I am working across multiple classes using a number of functions (which I will not list as it is irrelevant for what I am asking). I already have a smallChange()method and a fitnessfunction - could there be a chance that I would need to create a number of different versions of said methods? For example, I have something like:
我正在使用许多函数跨多个类工作（我不会列出它，因为它与我的要求无关）。我已经有了一个smallChange()方法和一个fitness函数——我是否有可能需要创建多个不同版本的所述方法？例如，我有类似的东西：
public static ArrayList<Integer> smallChange(ArrayList<Integer> solution){
//Code is here.
}
Could I possibly need another version of this method which accepts different parameters? Something along the lines of:
我可能需要接受不同参数的此方法的另一个版本吗？类似的东西：
public static double smallChange(double d){
//Code is here.
}
All I require is a basic idea of how this would look when written in Java - I will be able to adapt it to my code once I know what it should look like in the correct syntax, but I cannot seem to get past this particular hurdle.
我所需要的只是一个关于用 Java 编写时的外观的基本概念 - 一旦我知道它在正确的语法中应该是什么样子，我将能够使其适应我的代码，但我似乎无法克服这个特殊的障碍.
采纳答案by iluxa
The basic code should look like this:
基本代码应如下所示：
public class YourClass {
public static Solution doYourStuff(double startingTemperature, int numberOfIterations, double coolingRate) {
double t = startingTemperature;
Solution x = createRandomSolution();
double ti = t;
for (int i = 0; i < numberOfIterations; i ++) {
double f = calculateFitness(x);
Solution mutatedX = mutate(x);
double newF = calculateFitness(mutatedX);
if (newF < f) {
double p = PR(); // no idea what you're talking about here
if (p > UR(0, 1)) { // likewise
// then do nothing
} else {
x = mutatedX;
}
ti = t * coolingRate;
}
}
return x;
}
static class Solution {
// no idea what's in here...
}
}
Now as far as wanting different versions of smallChange() method - totally doable, but you have to read up on inheritancea little bit
现在就想要不同版本的 smallChange() 方法 - 完全可行，但您必须稍微阅读继承
回答by crowne
You can compare your answer to the code provided for the textbook
Artificial Intelligence a Modern Approach.
您可以将您的答案与为教科书《
人工智能现代方法》提供的代码进行比较。
回答by ProfPlum
Also, a Java-based approach to teaching simulated annealing (with sample code) is here:
此外，这里有一种基于 Java 的模拟退火教学方法（带有示例代码）：
Neller, Todd. Teaching Stochastic Local Search, in I. Russell and Z. Markov, eds. Proceedings of the 18th International FLAIRS Conference (FLAIRS-2005), Clearwater Beach, Florida, May 15-17, 2005, AAAI Press, pp. 8-13.
内勒，托德。随机局部搜索教学，在 I. Russell 和 Z. Markov，编辑。第 18 届国际 FLAIRS 会议论文集 (FLAIRS-2005)，佛罗里达州克利尔沃特海滩，2005 年 5 月 15-17 日，AAAI 出版社，第 8-13 页。
Related resources, references, and demos are here: http://cs.gettysburg.edu/~tneller/resources/sls/index.html
相关资源、参考资料和演示在这里：http: //cs.gettysburg.edu/~tneller/resources/sls/index.html
