metropolisupdator.java

来自「pso源程序」· Java 代码 · 共 55 行

/**
 * Description: Updating A as B accoroding to Metropolis algorithm.
 *
 * @ Author        Create/Modi     Note
 * Xiaofeng Xie    Apr 28, 2006    MAOS-TSP Beta 1.1.002
 *
 * @version 1.0
 * @Since MAOS-TSP Beta 1.1.002
 */

package maosKernel.behavior.update;

import Global.methods.*;
import Global.basic.nodes.utilities.*;

import maosKernel.represent.*;
import maosKernel.memory.*;
import maosKernel.represent.landscape.*;

public class MetropolisUpdator extends AbsUpdator implements ISetLandscapeInfoEngine {
  private double Temperature = 1;
  private IEncodedDataEvaluateEngine evaluateEngine;

  public MetropolisUpdator() {
  }

  protected void setRootInfo(AbsLandscape landscape) {
    evaluateEngine = landscape;
  }

  public void initUtilities() {
    super.initUtilities();
    initUtility(new DoubleUtility("Temperature", Temperature));
  }

  public void shortcutInit() throws Exception {
    super.shortcutInit();
    Temperature = TypeConverter.toDouble(getValue("Temperature"));
  }

  public boolean updateBehavior(EncodedState acceptPoint, EncodedState donatePoint) {
    if (EncodedStateHandler.evaluate(evaluateEngine, donatePoint, acceptPoint)) {
      acceptPoint.importEncodeState(donatePoint);
      return true;
    } else {
      int deltaV = donatePoint.getEncodeInfo().getGlobalCost()-acceptPoint.getEncodeInfo().getGlobalCost();
      if (Math.exp(-deltaV/Temperature)>Math.random()) {
        acceptPoint.importEncodeState(donatePoint);
        return true;
      }
    }
    return false;
  }
}