parameters.java

一个很好的LIBSVM的JAVA源码。对于要研究和改进SVM算法的学者。可以参考。来自数据挖掘工具YALE工具包。

/*
 *  YALE - Yet Another Learning Environment
 *  Copyright (C) 2001-2004
 *      Simon Fischer, Ralf Klinkenberg, Ingo Mierswa, 
 *          Katharina Morik, Oliver Ritthoff
 *      Artificial Intelligence Unit
 *      Computer Science Department
 *      University of Dortmund
 *      44221 Dortmund,  Germany
 *  email: [e-mail]
 *  web:   http://yale.cs.uni-dortmund.de/
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License as 
 *  published by the Free Software Foundation; either version 2 of the
 *  License, or (at your option) any later version. 
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 *  USA.
 */
package edu.udo.cs.yale.operator.parameter;

import edu.udo.cs.yale.tools.LogService;

import java.util.Iterator; 
import java.util.List; 
import java.util.Map;
import java.util.HashMap;
import java.util.Set;

/** This class is a collection of the parameter values of a single operator.
 *  Instances of <code>Parameters</code> are created with respect to the
 *  declared list of <code>ParameterTypes</code> of an operator. If parameters
 *  are set using the <code>setParameter()</code> method and the value exceeds
 *  the range, it is automatically corrected. If parameters are queried that
 *  are not set, their default value is returned.
 *
 *  @version $Id: Parameters.java,v 2.9 2004/08/27 11:57:42 ingomierswa Exp $
 */
public class Parameters {

    /** Maps parameter keys (i.e. Strings) to their value (Objects). */
    private Map keyToValueMap = new HashMap();
    /** Maps parameter keys (i.e. Strings) to their <code>ParameterType</code>. */
    private Map keyToTypeMap  = new HashMap();

    /** Constructs an instance of <code>Parameters</code> for the given list of 
     *  <code>ParameterTypes</code>. */
    public Parameters(List parameterTypes) {
	Iterator i = parameterTypes.iterator();
	while (i.hasNext()) {
	    ParameterType type = (ParameterType)i.next();
	    keyToTypeMap.put(type.getKey(), type);
	} 
    }

    /** Performs a deep clone on this parameters. */
    public Object clone() {
	Parameters clone = new Parameters(new java.util.LinkedList());
	Iterator i = keyToValueMap.keySet().iterator();
	while (i.hasNext()) {
	    Object key = i.next();
	    clone.keyToValueMap.put(key, keyToValueMap.get(key));
	}
	i = keyToTypeMap.keySet().iterator();
	while (i.hasNext()) {
	    Object key = i.next();
	    clone.keyToTypeMap.put(key, keyToTypeMap.get(key));
	}
	return clone;
    }

    /** Returns the type of the parameter with the given type. */
    public ParameterType getParameterType(String key) {
	return (ParameterType)keyToTypeMap.get(key);
    }

    /** Sets the parameter for the given key after performing a range-check. */
    public void setParameter(String key, Object value) {
	ParameterType type = (ParameterType)keyToTypeMap.get(key);
	if (type == null) {
	    LogService.logMessage("Illegal key: '"+key+"'", LogService.WARNING);
	    if (value instanceof List) {
		type = new ParameterTypeList(key, "guessed", new ParameterTypeString(null, null));
	    } else {
		type = new ParameterTypeString(key, "guessed");  
	    }	    
	    keyToTypeMap.put(key, type);
	} 
	keyToValueMap.put(key, type.checkValue(value));		
    }

    /** Sets the parameter without performing a range check. */
    public void setParameterWithoutCheck(String key, Object value) {
	if (value == null) {
	    keyToValueMap.remove(key);
	} else {
	    keyToValueMap.put(key, value);
	}
    }

    /** Returns the value of the given parameter. If it was not yet set, the default value is
     *  set now and a log message is issued. If the <code>ParameterType</code> does not
     *  provide a default value, this may result in an error message. In subsequent calls
     *  of this method, the parameter will be set. */
    public Object getParameter(String key) {
	if (keyToValueMap.containsKey(key)) {
	    return keyToValueMap.get(key);
	} else {
	    ParameterType type = (ParameterType)keyToTypeMap.get(key);
	    if (type == null) { return null; }
	    Object value = type.getDefaultValue();
	    if ((value == null) && !type.isOptional()) {
		LogService.logMessage("Parameter '"+key+"' is not set and has no default value.", LogService.ERROR);
	    } else {
		keyToValueMap.put(key, value);
		LogService.logMessage("Parameter '"+key+"' is not set. Using default ('"+type.toString(value)+"').", LogService.MINIMUM);
	    }	    
	    return value;
	}	
    }

    /** Returns a set view of all parameter keys. */
    public Set getKeys() {
	return keyToValueMap.keySet();
    }

    /** Returns true if the given parameters are not null and are the same like this parameters. */
    public boolean equals(Object o) {
	if (o == null)
	    return false;
	if (o instanceof Parameters) {
	    Parameters params = (Parameters)o;
	    if (params.keyToValueMap.size() != this.keyToValueMap.size())
		return false;
	    Iterator i = this.keyToValueMap.keySet().iterator();
	    while (i.hasNext()) {
		Object key = i.next();
		Object value = params.keyToValueMap.get(key);
		if ((value == null) || !value.equals(this.keyToValueMap.get(key)))
		    return false;
	    }
	    return true;
	} else {
	    return false;
	}
    }

    /** Writes a portion of the xml configuration file specifying the parameters
     *  that differ from their default value. */
    public String getXML(String indent) {
	StringBuffer result = new StringBuffer();
	Iterator i = keyToValueMap.keySet().iterator();
	while (i.hasNext()) {
	    String key         = (String)i.next();
	    Object value       = keyToValueMap.get(key);
	    ParameterType type = (ParameterType)keyToTypeMap.get(key);
	    if (type != null) {
		result.append(type.getXML(indent, key, value));
	    } else {
		result.append(indent + "<parameter key=\""+key+"\"\tvalue=\"" + value.toString() + "\"/>\n");
	    }	    
	}
	return result.toString();
    }
}