eoSymMutate.h

/*          
 *             Copyright (C) 2005 Maarten Keijzer
 *
 *          This program is free software; you can redistribute it and/or modify
 *          it under the terms of version 2 of the GNU General Public License as 
 *          published by the Free Software Foundation. 
 *
 *          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
 */

#ifndef SYMMUTATE_H
#define SYMMUTATE_H

#include <TreeBuilder.h>
#include <NodeSelector.h>

#include <eoSym.h>
#include <eoOp.h>

template <class EoType>
class eoSymSubtreeMutate : public eoMonOp<EoType> {
    
        TreeBuilder& subtree_builder;
        NodeSelector& node_selector;
    public :
        
        eoSymSubtreeMutate(TreeBuilder& _subtree_builder, NodeSelector& _node_selector)
        : subtree_builder(_subtree_builder), node_selector(_node_selector) {}
        
        
        bool operator()(EoType& tomutate) {
            unsigned xover_point = node_selector.select_node(tomutate).idx();
            // create subtree
            Sym newtree = subtree_builder.build_tree(6, true); // TODO, parameterize
            static_cast<Sym&>(tomutate) = insert_subtree(tomutate, xover_point, newtree);
            return true;
        }
    
};

extern bool mutate(Sym& sym, double p, const LanguageTable& table);

template <class EoType>
class eoSymNodeMutate : public eoMonOp<EoType> {
    
        LanguageTable& table;
        double own_mutation_rate;
        bool   own_is_rate_absolute;
        

    public:
        
        double& mutation_rate;
        bool& is_rate_absolute;
            
        eoSymNodeMutate(LanguageTable& _table)
        :   table(_table),
            own_mutation_rate(1.0),
            own_is_rate_absolute(false), // this means a probability of node mutation of 1/sym.size()
            mutation_rate(own_mutation_rate),
            is_rate_absolute(own_is_rate_absolute)
        {}

        eoSymNodeMutate(LanguageTable& _table, double& _mutation_rate, bool& _is_rate_absolute) 
        :   table(_table),
            mutation_rate(_mutation_rate),
            is_rate_absolute(_is_rate_absolute) 
        {}

        
        bool operator()(EoType& _eo) {
            double p = mutation_rate;
            if (!is_rate_absolute) p /= _eo.size();

            return mutate(_eo, p, table);
        }
        
};

extern bool mutate_constants(Sym& sym, double stdev);
template <class EoType>
class eoSymConstantMutate : public eoMonOp<EoType> {
    
    double& stdev;

    
    public :
    eoSymConstantMutate(double& _stdev) : stdev(_stdev) {}

    bool operator()(EoType& _eo) {
        return mutate_constants(_eo, stdev);
    }
    
    
};

#endif

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