annealingscheme.java

模拟退火是一种启发式算法

package org.theblueplanet.annealing;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
 *  Encapsulates the parameters passed around by the UI layer of JSimul
 *
 * @author     Charles M間nin
 * @since    October 17, 2001
 * @version    1.0
 */
public class AnnealingScheme {
    private double temperature; // Log10 value
    private int coolingRate;    // 0=no cooling 1=100% T drop
    private int nIterations;    // Number of iterations before cooling is applied
    private int iteration;      // The current iteration number;
    private double[] offset;
    private double tolerance;
    private double defaultTemperature  = 1.e+6;
    private int defaultCoolingRate     = 20;
    private int defaultNIterations     = 20;
    private double defaultTolerance    = 1.e-5;
    private int ndim;
    private Class ofClass;
    private String className;
    private Method method;
    private String methodName;

    private static String ofInterface  = "org.theblueplanet.annealing.ObjectiveFunction";

    /**
     *  Default constructor for the AnnealingScheme object
     */
    public AnnealingScheme() {
        setDefaultValues();
    }

    /**
     *  Convenience constructor for the AnnealingScheme object
     *
     * @param  temperature    The initial temperature
     * @param  coolingRate    The cooling rate (from 0 to 1)
     * @param  nIterations    The number of iterations before cooling is applied
     * @param  tolerance      Description of Parameter
     * @param  offset         Description of Parameter
     * @param  className      Description of Parameter
     * @param  methodName     Description of Parameter
     */
    public AnnealingScheme(double temperature, int coolingRate, int nIterations,
            double tolerance, double[] offset, String className,
            String methodName)
        throws Exception {
        setTemperature(temperature);
        setCoolingRate(coolingRate);
        setNIterations(nIterations);
        setTolerance(tolerance);
        setOffset(offset);
        setClassName(className);
        setOfClass(className);
        setMethodName(methodName);
        setMethod(methodName);
        iteration = 0;
    }

    /**
     *  Sets the Temperature attribute of the AnnealingScheme object
     *
     * @param  temperature  The new Temperature value
     */
    public void setTemperature(double temperature) {
        this.temperature = temperature;
    }

    /**
     *  Sets the Tolerance attribute of the AnnealingScheme object
     *
     * @param  tolerance  The new Tolerance value
     */
    public void setTolerance(double tolerance) {
        this.tolerance = tolerance;
    }

    /**
     *  Sets the Offset attribute of the AnnealingScheme object
     *
     * @param  offset  The new Offset value
     */
    public void setOffset(double[] offset) {
        this.offset = offset;
    }

    /**
     *  Sets the Offset attribute of the AnnealingScheme object
     *
     * @param  offset  The new Offset value
     */
    public void setOffset(double offset, int ii) {
        this.offset[ii] = offset;
    }

    /**
     *  Sets the Ndim attribute of the AnnealingScheme object
     *
     * @param  ndim  The new Ndim value
     */
    public void setNdim(int ndim) {
        this.ndim = ndim;
    }

    /**
     *  Sets the OfClass attribute of the AnnealingScheme object
     *
     * @param  className                      The new OfClass value
     * @exception  ClassNotFoundException     Description of Exception
     * @exception  IllegalAccessException     Description of Exception
     * @exception  NoSuchFieldException       Description of Exception
     * @exception  InstantiationException     Description of Exception
     * @exception  NoSuchMethodException      Description of Exception
     * @exception  InvocationTargetException  Description of Exception
     */
    public void setOfClass(String className)
        throws ClassNotFoundException, IllegalAccessException,
            NoSuchFieldException, InstantiationException,
            NoSuchMethodException, InvocationTargetException {
        ofClass = Class.forName(className);
        Class[] interfaces  = ofClass.getInterfaces();
        boolean found       = false;
        for (int ii = 0; ii < interfaces.length; ii++) {
            if (interfaces[ii].getName().equals(ofInterface)) {
                found = true;
                break;
            }
        }
        if (!found) {
            throw new InstantiationException("Objective function does not implement " + ofInterface);
        }
        Method getNdim      = ofClass.getMethod("getNdim", null);
        setNdim(((Integer) getNdim.invoke(ofClass.newInstance(), null)).intValue());
    }

    /**
     *  Sets the OfClass attribute of the AnnealingScheme object
     *
     * @exception  ClassNotFoundException     Description of Exception
     * @exception  IllegalAccessException     Description of Exception
     * @exception  NoSuchFieldException       Description of Exception
     * @exception  InstantiationException     Description of Exception
     * @exception  NoSuchMethodException      Description of Exception
     * @exception  InvocationTargetException  Description of Exception
     */
    public void setOfClass()
        throws ClassNotFoundException, IllegalAccessException,
            NoSuchFieldException, InstantiationException,
            NoSuchMethodException, InvocationTargetException {
        ofClass = Class.forName(getClassName());
        Class[] interfaces  = ofClass.getInterfaces();
        boolean found       = false;
        for (int ii = 0; ii < interfaces.length; ii++) {
            if (interfaces[ii].getName().equals(ofInterface)) {
                found = true;
                break;
            }
        }
        if (!found) {
            throw new InstantiationException("Objective function does not implement " + ofInterface);
        }
        Method getNdim      = ofClass.getMethod("getNdim", null);
        setNdim(((Integer) getNdim.invoke(ofClass.newInstance(), null)).intValue());
    }

    /**
     *  Sets the ClassName attribute of the AnnealingScheme object
     *
     * @param  className  The new ClassName value
     */
    public void setClassName(String className) {
        this.className = className;
    }

    /**
     *  Sets the Method attribute of the AnnealingScheme object
     *
     * @param  methodName  The new Method value
     */
    public void setMethod(String methodName) {
        Method[] methods  = ofClass.getDeclaredMethods();
        for (int i = 0; i < methods.length; i++) {
            if (methods[i].getName().equals(methodName)) {
                this.method = methods[i];
                break;
            }
        }
    }

    /**
     *  Sets the Method attribute of the AnnealingScheme object
     */
    public void setMethod() {
        Method[] methods  = ofClass.getDeclaredMethods();
        for (int i = 0; i < methods.length; i++) {
            if (methods[i].getName().equals(getMethodName())) {
                this.method = methods[i];
            }
        }
    }

    /**
     *  Sets the MethodName attribute of the AnnealingScheme object
     *
     * @param  methodName  The new MethodName value
     */
    public void setMethodName(String methodName) {
        this.methodName = methodName;
    }

    /**
     *  Sets the CoolingRate attribute of the AnnealingScheme object
     *
     * @param  coolingRate    The new CoolingRate value
     */
    public void setCoolingRate(int coolingRate) {
        this.coolingRate = coolingRate;
    }

    /**
     *  Sets the NIterations attribute of the AnnealingScheme object
     *
     * @param  nIterations  The new NIterations value
     */
    public void setNIterations(int nIterations) {
        this.nIterations = nIterations;
    }

    /**
     *  Sets the DefaultValues for the AnnealingScheme object
     */
    public void setDefaultValues() {
        this.temperature = this.defaultTemperature;
        this.coolingRate = this.defaultCoolingRate;
        this.nIterations = this.defaultNIterations;
        this.tolerance = this.defaultTolerance;
        setDefaultOffset();
    }

    /**
     *  Sets the DefaultOffset for the AnnealingScheme object
     */
    public void setDefaultOffset() {
        offset = new double[ndim + 1];
        for (int ii = 0; ii <= ndim; ii++) {
            offset[ii] = 0.0;
        }
    }

    /**
     *  Gets the ClassName attribute of the AnnealingScheme object
     *
     * @return    The ClassName value
     */
    public String getClassName() {
        return className;
    }

    /**
     *  Gets the MethodName attribute of the AnnealingScheme object
     *
     * @return    The MethodName value
     */
    public String getMethodName() {
        return methodName;
    }

    /**
     *  Gets the Offset attribute of the AnnealingScheme object
     *
     * @return    The Offset value
     */
    public double[] getOffset() {
        return offset;
    }

    /**
     *  Gets the Temperature attribute of the AnnealingScheme object
     *
     * @return    The Temperature value
     */
    public double getTemperature() {
        return temperature;
    }

    /**
     *  Gets the CoolingRate attribute of the AnnealingScheme object
     *
     * @return    The CoolingRate value
     */
    public int getCoolingRate() {
        return coolingRate;
    }

    /**
     *  Gets the NIterations attribute of the AnnealingScheme object
     *
     * @return    The NIterations value
     */
    public int getNIterations() {
        return nIterations;
    }

    /**
     *  Gets the Tolerance attribute of the AnnealingScheme object
     *
     * @return    The Tolerance value
     */
    public double getTolerance() {
        return tolerance;
    }

    /**
     *  Gets the Ndim attribute of the AnnealingScheme object
     *
     * @return    The Ndim value
     */
    public int getNdim() {
        return ndim;
    }

    /**
     *  Gets the OfClassObject attribute of the AnnealingScheme object
     *
     * @return                             The OfClassObject value
     * @exception  InstantiationException  Description of Exception
     * @exception  IllegalAccessException  Description of Exception
     */
    public Object getOfClassObject()
        throws InstantiationException, IllegalAccessException {
        return getOfClass().newInstance();
    }

    /**
     *  Gets the OfClass attribute of the AnnealingScheme object
     *
     * @return    The OfClass value
     */
    public Class getOfClass() {
        return ofClass;
    }

    /**
     *  Gets the Method attribute of the AnnealingScheme object
     *
     * @return    The Method value
     */
    public Method getMethod() {
        return method;
    }

    /**
     *  Resets iteration to 0
     */
    public void resetIteration() {
        iteration = 0;
    }

    /**
     *  Increments the iteration field and cools if threshold is reached
     */
    public void updateIteration() {
        iteration++;
        if (iteration == (nIterations - 1)) {
            cool();
        }
    }

    /**
     *  String representation of the AnnealingScheme Object
     *
     * @return    The String representation of the Object
     */
    public String toString() {
        String string  = null;
        try {
            StringBuffer sb  = new StringBuffer();
            for (int ii = 1; ii < offset.length; ii++) {
                sb.append("offset[" + ii + "]=" + offset[ii] + " ");
            }
            sb.append("\n");
            sb.append("T=" + getTemperature() + " R=" + getCoolingRate() +
                    "% N=" + getNIterations() + " tol=" + getTolerance() +
                    "\nClass=" + getClassName() +
                    "\nMethod=" + this.getMethodName());
            string = sb.toString();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return string;
    }

    /**
     *  Updates temperature according to cooling scheme;
     */
    private void cool() {
        temperature *= (100. - coolingRate);
    }

}