paradiseo/eo/contrib/mathsym/gen/NodeSelector.cpp
2012-08-30 11:30:11 +02:00

50 lines
1.6 KiB
C++

/*
* 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
*/
#include "NodeSelector.h"
#include "Sym.h"
#include <utils/eoRNG.h>
// If subtree is not set (by randomnodeselector for instance, find it now
Sym NodeSelector::NodeSelection::subtree() {
if (subtree_.empty()) {
subtree_ = get_subtree(root_, subtree_index_);
}
return subtree_;
}
NodeSelector::NodeSelection RandomNodeSelector::select_node(Sym sym) const {
unsigned idx = rng.random(sym.size());
return NodeSelection(sym, idx, Sym() ); // empty subtree, find it when needed
}
NodeSelector::NodeSelection BiasedNodeSelector::select_node(Sym sym) const {
unsigned p = rng.random(sym.size());
Sym res;
for (unsigned i = 0; i < nRounds; ++i) {
res = get_subtree(sym, p);
if (res.args().size() > 0) break;
p = rng.random(sym.size());
}
return NodeSelection(sym, p, res);
}