package ac.essex.ooechs.ecj.ecj2java.example.terminals; 
 
import ac.essex.ooechs.ecj.ecj2java.nodes.ParseableGPNode; 
import ac.essex.ooechs.ecj.ecj2java.example.data.DoubleData; 
import ec.EvolutionState; 
import ec.Problem; 
import ec.gp.GPData; 
import ec.gp.ADFStack; 
import ec.gp.GPIndividual; 
 
/** 
 * 
 * <p> 
 * Allows the GP tree to access the variable X, from which it is supposed 
 * to calculate Y, in some manner. 
 * </p> 
 * 
 *  
 * <p/> 
 * 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, 
 * provided that any use properly credits the author. 
 * 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 at http://www.gnu.org 
 * </p> 
 * 
 * @author Olly Oechsle, University of Essex, Date: 05-Sep-2006 
 * @version 1.0 
 */ 
public class X extends ParseableGPNode { 
 
    public X() { 
        super("x", 0); 
    } 
 
    /** 
     * Called as the function is evaluated. 
     */ 
    public void eval(final EvolutionState state, final int thread, final GPData input, final ADFStack stack, final GPIndividual individual, final Problem problem) { 
 
        DoubleData rd = ((DoubleData) (input)); 
 
        // then add them together 
        rd.x = ((ac.essex.ooechs.ecj.ecj2java.example.problems.MathsProblem) problem).x; 
    } 
 
    public int getObjectType() { 
        return DOUBLE; 
    } 
 
    /** 
     * Convert this code to pure Java 
     */ 
    public String getJavaCode() { 
        return "x"; 
    } 
 
 
}