git-svn-id: svn://scm.gforge.inria.fr/svnroot/paradiseo@34 331e1502-861f-0410-8da2-ba01fb791d7f

trunk/paradiseo-mo/src/moSA.h

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+// -*- mode: c++; c-indent-level: 4; c++-member-init-indent: 8; comment-column: 35; -*-
+
+// "moSA.h"
+
+// (c) OPAC Team, LIFL, 2003-2006
+
+/* LICENCE TEXT
+   
+   Contact: paradiseo-help@lists.gforge.inria.fr
+*/
+
+#ifndef __moSA_h
+#define __moSA_h
+
+#include <unistd.h>
+
+#include <eoOp.h>
+#include <eoEvalFunc.h>
+
+#include "moAlgo.h"
+#include "moRandMove.h"
+#include "moMoveIncrEval.h"
+#include "moCoolSched.h"
+#include "moSolContinue.h"
+
+#include <math.h>
+
+//! Simulated Annealing (SA)
+/*!
+  Class that describes a Simulated Annealing algorithm.
+*/
+template < class M > class moSA:public moAlgo < typename M::EOType >
+{
+
+  //! Alias for the type
+  typedef
+    typename
+    M::EOType
+    EOT;
+
+  //! Alias for the fitness
+  typedef
+    typename
+    EOT::Fitness
+    Fitness;
+
+public:
+
+  //! SA constructor
+  /*!
+     All the boxes used by a SA need to be given.
+
+     \param __move_rand a move generator (generally randomly).
+     \param __incr_eval a (generaly) efficient evaluation function 
+     \param __cont a stopping criterion.
+     \param __init_temp the initial temperature.
+     \param __cool_sched a cooling schedule, describes how the temperature is modified.
+     \param __full_eval a full evaluation function.
+   */
+  moSA (moRandMove < M > &__move_rand,
+	moMoveIncrEval < M > &__incr_eval,
+	moSolContinue < EOT > &__cont,
+	double __init_temp,
+	moCoolSched & __cool_sched, eoEvalFunc < EOT > &__full_eval):
+  move_rand (__move_rand),
+  incr_eval (__incr_eval),
+  cont (__cont),
+  init_temp (__init_temp),
+  cool_sched (__cool_sched),
+  full_eval (__full_eval)
+  {
+
+  }
+
+  //! function that launches the SA algorithm.
+  /*!
+     As a moTS or a moHC, the SA can be used for HYBRIDATION in an evolutionary algorithm.
+
+     \param __sol a solution to improve.
+     \return TRUE.
+   */
+  bool operator   ()(EOT & __sol)
+  {
+
+    if (__sol.invalid ())
+      {
+	full_eval (__sol);
+      }
+
+    double
+      temp = init_temp;
+
+    M move;
+
+    EOT best_sol = __sol;
+
+    do
+      {
+
+	cont.init ();
+	do
+	  {
+
+	    move_rand (move);
+
+	    Fitness delta_fit = incr_eval (move, __sol) - __sol.fitness ();
+
+	    if (delta_fit > 0 || rng.uniform () < exp (delta_fit / temp))
+	      {
+
+		__sol.fitness (incr_eval (move, __sol));
+		move (__sol);
+
+		/* Updating the best solution found
+		   until now ? */
+		if (__sol.fitness () > best_sol.fitness ())
+		  best_sol = __sol;
+	      }
+
+	  }
+	while (cont (__sol));
+
+      }
+    while (cool_sched (temp));
+
+    __sol = best_sol;
+
+    return true;
+  }
+
+private:
+
+  //! A move generator (generally randomly)
+  moRandMove < M > &move_rand;
+
+  //! A (generally) efficient evaluation function.
+  moMoveIncrEval < M > &incr_eval;
+
+  //! Stopping criterion before temperature update
+  moSolContinue < EOT > &cont;
+
+  //! Initial temperature
+  double
+    init_temp;
+
+  //! The cooling schedule
+  moCoolSched & cool_sched;
+
+  //! A full evaluation function.
+  eoEvalFunc < EOT > &full_eval;	// Full evaluator.
+};
+
+#endif