Java tutorial
/* * This file is part of JGAP. * * JGAP offers a dual license model containing the LGPL as well as the MPL. * * For licensing information please see the file license.txt included with JGAP * or have a look at the top of class org.jgap.Chromosome which representatively * includes the JGAP license policy applicable for any file delivered with JGAP. */ package org.jgap.distr; import java.io.*; import java.util.*; import org.apache.commons.lang.builder.*; /** * Culture is a memory not being bound to a generation, but possibly persistent * during the whole history of a genotype (over all generations). * See GPConfiguration for current support of culture with Genetic Programming.<p> * Also see http://cs.gmu.edu/~sean/papers/culture-gp96.pdf * * @author Klaus Meffert * @since 2.3 */ public class Culture implements Serializable, Comparable { /** String containing the CVS revision. Read out via reflection!*/ private final static String CVS_REVISION = "$Revision: 1.16 $"; /** * The storage to use. */ private CultureMemoryCell[] m_memory; /** * Storage for named indices. */ private List m_memoryNames = new Vector(); /** * Number of memory cells available. */ private int m_size; /** * Width of a matrixed memory (optional, but necessary to set if you want * to treat the memory as a matrix). */ private int m_width; /** * Constructor. * * @param a_size the size of the memory in cells (CultureMemoryCell instances) * * @author Klaus Meffert * @since 2.3 */ public Culture(final int a_size) { if (a_size < 1) { throw new IllegalArgumentException("Size must be greater than zero!"); } m_size = a_size; m_memory = new CultureMemoryCell[m_size]; m_width = 1; } /** * Sets a memory cell with a given value. The memory cell will be newly * created for that. * * @param a_index index of the memory cell * @param a_value value to set in the memory * @param a_historySize size of history to use, or less than 1 for turning * history off * @param a_name informative name of the memory cell * @return newly created memory cell set with the given value * * @author Klaus Meffert * @since 2.3 */ public CultureMemoryCell set(final int a_index, final double a_value, final int a_historySize, final String a_name) { if (a_index < 0 || a_index >= size()) { throw new IllegalArgumentException("Illegal memory index!"); } CultureMemoryCell cell = new CultureMemoryCell(a_name, a_historySize); cell.setDouble(a_value); m_memory[a_index] = cell; return cell; } /** * Sets a memory cell with a given value. The memory cell will be newly * created for that. * * @param a_index index of the memory cell * @param a_value value to set in the memory * @param a_historySize size of history to use, or less than 1 for turning * history off * @param a_infotext informative name of the memory cell * @return newly created memory cell set with the given value * * @author Klaus Meffert * @since 3.0 */ public CultureMemoryCell set(final int a_index, final Object a_value, final int a_historySize, final String a_infotext) { if (a_index < 0 || a_index >= size()) { throw new IllegalArgumentException("Illegal memory index!"); } CultureMemoryCell cell = new CultureMemoryCell(a_infotext, a_historySize); cell.setValue(a_value); m_memory[a_index] = cell; return cell; } /** * Sets a memory cell with a given value. The memory cell will be newly * created for that. * * @param a_name named index of the memory cell * @param a_value value to set in the memory * @param a_historySize size of history to use, or less than 1 for turning * history off * @return newly created memory cell set with the given value * * @author Klaus Meffert * @since 3.0 */ public CultureMemoryCell set(final String a_name, final Object a_value, final int a_historySize) { if (a_name == null || a_name.length() < 1) { throw new IllegalArgumentException("Illegal memory name!"); } int index = m_memoryNames.indexOf(a_name); if (index < 0) { // Create new named index. // ----------------------- m_memoryNames.add(a_name); index = m_memoryNames.size() - 1; } CultureMemoryCell cell = new CultureMemoryCell(a_name, a_historySize); cell.setValue(a_value); m_memory[index] = cell; return cell; } /** * Retrieves the memory cell at the given index. * * @param a_index index of the memory cell to read out * @return stored memory cell at given index * * @author Klaus Meffert * @since 2.3 */ public CultureMemoryCell get(final int a_index) { if (a_index < 0 || a_index >= size()) { throw new IllegalArgumentException("Illegal memory index!"); } return m_memory[a_index]; } /** * Retrieves the memory cell at the given index. * * @param a_name name of the memory cell to read out * @return stored memory cell for given name, or null if name unknown * * @author Klaus Meffert * @since 3.0 */ public CultureMemoryCell get(final String a_name) { if (a_name == null || a_name.length() < 1) { throw new IllegalArgumentException("Illegal memory name!"); } int index = m_memoryNames.indexOf(a_name); if (index < 0) { throw new IllegalArgumentException("Memory name unknown: " + a_name); } return m_memory[index]; } /** * Checks if a memory cell with the given name exists. * * @param a_name the name of the cell to check * @return true: cell excists * * @author Klaus Meffert * @since 3.2 */ public boolean contains(final String a_name) { if (a_name == null || a_name.length() < 1) { throw new IllegalArgumentException("Illegal memory name!"); } int index = m_memoryNames.indexOf(a_name); return index >= 0; } /** * @return size of the memory * * @author Klaus Meffert * @since 2.3 */ public int size() { return m_memory.length; } /** * @return String representation of the cultural memory * * @author Klaus Meffert * @since 2.3 */ public String toString() { StringBuffer result = new StringBuffer("["); int len = m_memory.length; if (m_memory[0] == null) { result.append(m_memory[0]); } else { result.append(m_memory[0].toString()); } for (int i = 1; i < len; i++) { if (m_memory[i] == null) { result.append(";" + m_memory[i]); } else { result.append(";" + m_memory[i].toString()); } } result.append("]"); return result.toString(); } /** * Clears the memory. * * @author Klaus Meffert * @since 3.0 */ public void clear() { m_memory = new CultureMemoryCell[m_size]; m_memoryNames.clear(); } /** * @return cloned list of symbolic memory names * * @author Klaus Meffert * @since 3.0 */ public List getMemoryNames() { return new Vector(m_memoryNames); } /** * The equals-method. * @param a_other the other object to compare * @return true if the objects are regarded as equal * * @author Klaus Meffert * @since 3.0 */ public boolean equals(Object a_other) { try { return compareTo(a_other) == 0; } catch (ClassCastException cex) { cex.printStackTrace(); return false; } } /** * The compareTo-method. * * @param a_other the other object to compare * @return -1, 0, 1 * * @author Klaus Meffert * @since 3.0 */ public int compareTo(Object a_other) { Culture other = (Culture) a_other; if (other == null) { return 1; } // Problem: Vector does not implement Comparable. Thus we call toArray(). // ---------------------------------------------------------------------- return new CompareToBuilder().append(m_size, other.m_size).append(m_memory, other.m_memory) .append(m_memoryNames.toArray(), other.m_memoryNames.toArray()).toComparison(); } /** * Sets the width of the matrix memory. Important to call before using * setMatrix/getMatrix! * * @param a_width the width the matrix should have * * @author Klaus Meffert * @since 3.2 */ public void setMatrixWidth(int a_width) { int size = size(); if (a_width > size) { throw new IllegalArgumentException( "Width must not be greater than the" + " size of the memory (" + size + ") !"); } m_width = a_width; } /** * Stores a value in the matrix memory. Use setMatrixWidth(int) beforehand! * * @param a_x the first coordinate of the matrix (width) * @param a_y the second coordinate of the matrix (height) * @param a_value the value to store * @return created or used memory cell * * @author Klaus Meffert * @since 3.2 */ public CultureMemoryCell setMatrix(int a_x, int a_y, Object a_value) { int index = a_x * m_width + a_y; CultureMemoryCell cell = m_memory[index]; if (cell == null) { cell = new CultureMemoryCell(a_x + "_" + a_y, -1); } cell.setValue(a_value); m_memory[index] = cell; return cell; } /** * Reads a value from the matrix memory that was previously stored with * setMatrix(...). * * @param a_x the first coordinate of the matrix (width) * @param a_y the second coordinate of the matrix (height) * @return read value * * @author Klaus Meffert * @since 3.2 */ public CultureMemoryCell getMatrix(int a_x, int a_y) { int index = a_x * m_width + a_y; return get(index); } }