Migration from SVN

eo/contrib/mathsym/eo_interface/eoSymCrossover.cpp

@@ -0,0 +1,123 @@
+/*	    
+ *             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 <Sym.h>
+#include <NodeSelector.h>
+
+#include <eoSymCrossover.h>
+#include <utils/eoRNG.h>
+#include <vector>
+
+using namespace std;
+
+bool subtree_quad(Sym& a, Sym& b, NodeSelector& select) {
+    NodeSelector::NodeSelection sel_a = select.select_node(a);
+    NodeSelector::NodeSelection sel_b = select.select_node(b);
+
+    Sym aprime = insert_subtree(a, sel_a.idx(), sel_b.subtree() );
+    Sym bprime = insert_subtree(b, sel_b.idx(), sel_a.subtree() );
+
+    a = aprime;
+    b = bprime;
+    return true;
+}
+
+bool subtree_bin(Sym& a, const Sym& b, NodeSelector& select) {
+    NodeSelector::NodeSelection sel_a = select.select_node(a);
+    NodeSelector::NodeSelection sel_b = select.select_node(b);
+
+    a = insert_subtree(a, sel_a.idx(), sel_b.subtree());
+
+    return true;
+}
+
+Sym homologous_binimpl(Sym a, Sym b) {
+    
+    if(a == b) { return a; } // no point 
+    
+    bool use_a = rng.random(2);
+
+    token_t head = (use_a? a : b).token();
+    SymVec args = use_a?a.args() : b.args();
+
+    const SymVec& a_args = a.args();
+    const SymVec& b_args = b.args();
+    unsigned mn = std::min(a_args.size(), b_args.size());
+    
+    bool changed = !use_a;
+    
+    for (unsigned i = 0; i < mn; ++i) {
+	args[i] = homologous_binimpl(a_args[i], b_args[i]);
+	if (args[i] != a_args[i]) {
+	    changed = true;
+	}
+    }
+    
+    return changed? Sym(head, args) : a;
+}
+
+bool homologous_bin(Sym& a, const Sym& b) {
+    if (a==b) return false;
+    Sym org = a;
+    a = homologous_binimpl(a,b);
+    return org != a;
+}
+
+void set_size_levels(Sym sym, vector<unsigned>& l, vector<unsigned>& s, unsigned level = 1) {
+    l.push_back(level);
+    s.push_back(sym.size());
+    
+    for (unsigned i = 0; i < sym.args().size(); ++i) {
+        set_size_levels(sym.args()[i], l, s, level+1);
+    }
+}
+
+
+bool size_level_xover(Sym& a, const Sym& b) {
+    
+    Sym org = a;
+        
+    vector<unsigned> levela;
+    vector<unsigned> sizesa;
+    vector<unsigned> levelb;
+    vector<unsigned> sizesb;
+
+    set_size_levels(a, levela, sizesa);
+    set_size_levels(b, levelb, sizesb);
+
+    unsigned p0;
+    unsigned p1;
+    
+    for (unsigned tries = 0;; ++tries) {
+        p0 = rng.random(a.size());
+        p1 = rng.random(b.size());
+        
+        if (tries < 5 && (sizesa[p0] != sizesb[p1] && levela[p0] != levelb[p1])) {
+            continue;   
+        }
+
+        break;
+    }
+
+    a = insert_subtree(a, p0, get_subtree(b, p1));
+
+    return org != a;
+    
+}
+
+