crstrtgy.c

来自「NASA 开发使用的一个专家系统」· C语言 代码 · 共 914 行 · 第 1/3 页

   lastAct = NULL;

   /*=========================================================*/
   /* Find the insertion point in the agenda. The activation  */
   /* is placed before activations of lower salience and      */
   /* after activations of higher salience. Among activations */
   /* of equal salience, the OPS5 lex strategy is used for    */
   /* determining placement.                                  */
   /*=========================================================*/

   while (actPtr != NULL)
     {
      if (actPtr->salience > salience)
        {
         lastAct = actPtr;
         actPtr = actPtr->next;
        }
      else if (actPtr->salience < salience)
        { return(lastAct); }
      else
        {
         flag = ComparePartialMatches(actPtr,newActivation);

         if (flag == LESS_THAN)
           {
            lastAct = actPtr;
            actPtr = actPtr->next;
           }
         else if (flag == GREATER_THAN)
           { return(lastAct); }
         else /* flag == EQUAL */
           {
            if (timetag > actPtr->timetag)
              {
               lastAct = actPtr;
               actPtr = actPtr->next;
              }
            else
             { return(lastAct); }
           }
        }
     }

   /*===========================================*/
   /* Return the insertion point in the agenda. */
   /*===========================================*/
   
   return(lastAct);
  }

/*******************************************************************/
/* PlaceMEAActivation: Determines the location in the agenda       */
/*    where a new activation should be placed for the mea          */
/*    strategy. Returns a pointer to the activation after which    */
/*    the new activation should be placed (or NULL if the          */
/*    activation should be placed at the beginning of the agenda). */
/*******************************************************************/
static ACTIVATION *PlaceMEAActivation(actPtr,newActivation)
  ACTIVATION *actPtr;
  ACTIVATION *newActivation;
  {
   int salience;
   unsigned long timetag;
   ACTIVATION *lastAct;
   int flag;
   long int cWhoset, oWhoset;

   if (newActivation->sortedBasis == NULL)
     { newActivation->sortedBasis = SortPartialMatch(newActivation->basis); }

   /*============================================*/
   /* Set up initial information for the search. */
   /*============================================*/

   timetag = newActivation->timetag;
   salience = newActivation->salience;
   lastAct = NULL;

   /*=========================================================*/
   /* Find the insertion point in the agenda. The activation  */
   /* is placed before activations of lower salience and      */
   /* after activations of higher salience. Among activations */
   /* of equal salience, the OPS5 mea strategy is used for    */
   /* determining placement.                                  */
   /*=========================================================*/

   while (actPtr != NULL)
     {
      if (actPtr->salience > salience)
        {
         lastAct = actPtr;
         actPtr = actPtr->next;
        }
      else if (actPtr->salience < salience)
        { return(lastAct); }
      else
        {
         cWhoset = -1;
         oWhoset = -1;
         if (GetMatchingItem(newActivation,0) != NULL)
           { cWhoset = GetMatchingItem(newActivation,0)->timeTag; }
         if (GetMatchingItem(actPtr,0) != NULL)
           { oWhoset = GetMatchingItem(actPtr,0)->timeTag; }
         if (oWhoset < cWhoset)
           {
            if (cWhoset > 0) flag = GREATER_THAN;
            else flag = LESS_THAN;
           }
         else if (oWhoset > cWhoset)
           {
            if (oWhoset > 0) flag = LESS_THAN;
            else flag = GREATER_THAN;
           }
         else
           { flag = ComparePartialMatches(actPtr,newActivation); }

         if (flag == LESS_THAN)
           {
            lastAct = actPtr;
            actPtr = actPtr->next;
           }
         else if (flag == GREATER_THAN)
           { return(lastAct); }
         else /* flag == EQUAL */
           {
            if (timetag > actPtr->timetag)
              {
               lastAct = actPtr;
               actPtr = actPtr->next;
              }
            else
             { return(lastAct); }
           }
        }
     }

   /*===========================================*/
   /* Return the insertion point in the agenda. */
   /*===========================================*/
   
   return(lastAct);
  }

/*********************************************************************/
/* PlaceComplexityActivation: Determines the location in the agenda  */
/*    where a new activation should be placed for the complexity     */
/*    strategy. Returns a pointer to the activation  after which the */
/*    new activation should be placed (or NULL if the activation     */
/*    should be placed at the beginning of the agenda).              */
/*********************************************************************/
static ACTIVATION *PlaceComplexityActivation(actPtr,newActivation)
  ACTIVATION *actPtr;
  ACTIVATION *newActivation;
  {
   int salience, complexity;
   unsigned long timetag;
   ACTIVATION *lastAct;

   /*========================================*/
   /* Set up initial information for search. */
   /*========================================*/

   timetag = newActivation->timetag;
   salience = newActivation->salience;
   complexity = newActivation->theRule->complexity;
   lastAct = NULL;

   /*=========================================================*/
   /* Find the insertion point in the agenda. The activation  */
   /* is placed before activations of lower salience and      */
   /* after activations of higher salience. Among activations */
   /* of equal salience, the activation is placed before      */
   /* activations of equal or lessor complexity.              */
   /*=========================================================*/

   while (actPtr != NULL)
     {
      if (actPtr->salience > salience)
        {
         lastAct = actPtr;
         actPtr = actPtr->next;
        }
      else if (actPtr->salience < salience)
        { return(lastAct); }
      else if (complexity < (int) actPtr->theRule->complexity)
        {
         lastAct = actPtr;
         actPtr = actPtr->next;
        }
      else if (complexity > (int) actPtr->theRule->complexity)
        { return(lastAct); }
      else if (timetag > actPtr->timetag)
        {
         lastAct = actPtr;
         actPtr = actPtr->next;
        }
      else
        { return(lastAct); }
     }

   /*===========================================*/
   /* Return the insertion point in the agenda. */
   /*===========================================*/

   return(lastAct);
  }

/*********************************************************************/
/* PlaceSimplicityActivation: Determines the location in the agenda  */
/*    where a new activation should be placed for the simplicity     */
/*    strategy. Returns a pointer to the activation  after which the */
/*    new activation should be placed (or NULL if the activation     */
/*    should be placed at the beginning of the agenda).              */
/*********************************************************************/
static ACTIVATION *PlaceSimplicityActivation(actPtr,newActivation)
  ACTIVATION *actPtr;
  ACTIVATION *newActivation;
  {
   int salience, complexity;
   unsigned long timetag;
   ACTIVATION *lastAct;

   /*============================================*/
   /* Set up initial information for the search. */
   /*============================================*/

   timetag = newActivation->timetag;
   salience = newActivation->salience;
   complexity = newActivation->theRule->complexity;
   lastAct = NULL;

   /*=========================================================*/
   /* Find the insertion point in the agenda. The activation  */
   /* is placed before activations of lower salience and      */
   /* after activations of higher salience. Among activations */
   /* of equal salience, the activation is placed after       */
   /* activations of equal or greater complexity.             */
   /*=========================================================*/

   while (actPtr != NULL)
     {
      if (actPtr->salience > salience)
        {
         lastAct = actPtr;
         actPtr = actPtr->next;
        }
      else if (actPtr->salience < salience)
        { return(lastAct); }
      else if (complexity > (int) actPtr->theRule->complexity)
        {
         lastAct = actPtr;
         actPtr = actPtr->next;
        }
      else if (complexity < (int) actPtr->theRule->complexity)
        { return(lastAct); }
      else if (timetag > actPtr->timetag)
        {
         lastAct = actPtr;
         actPtr = actPtr->next;
        }
      else
       { return(lastAct); }
     }

   /*===========================================*/
   /* Return the insertion point in the agenda. */
   /*===========================================*/
   
   return(lastAct);
  }

/*******************************************************************/
/* PlaceRandomActivation: Determines the location in the agenda    */
/*    where a new activation should be placed for the random       */
/*    strategy. Returns a pointer to the activation  after which   */
/*    the new activation should be placed (or NULL if the          */
/*    activation should be placed at the beginning of the agenda). */
/*******************************************************************/
static ACTIVATION *PlaceRandomActivation(actPtr,newActivation)
  ACTIVATION *actPtr;
  ACTIVATION *newActivation;
  {
   int salience, randomID;
   unsigned long timetag;
   ACTIVATION *lastAct;

   /*============================================*/
   /* Set up initial information for the search. */
   /*============================================*/

   timetag = newActivation->timetag;
   salience = newActivation->salience;
   randomID = newActivation->randomID;
   lastAct = NULL;

   /*=========================================================*/
   /* Find the insertion point in the agenda. The activation  */
   /* is placed before activations of lower salience and      */
   /* after activations of higher salience. Among activations */
   /* of equal salience, the placement of the activation is   */
   /* determined through the generation of a random number.   */
   /*=========================================================*/

   while (actPtr != NULL)
     {