/* Concept.C * * A concept is a boolean combination of features. A feature is an attribute * together with a value for that attribute. "feature" is just another * word for "value". For this program, we assume that all concepts are * purely conjunctive. *//* * Copyright 1994, Brown University, Providence, RI * See end of file for full copyright information */#include "Concept.H"#include "Example.H"#include "Version.H"#include "Dimension.H"#include "String.H"// Construct an empty concept. No features.Concept::Concept(){  for(int x = 0; x < Version::num_dimensions; x++)    features[x] = NO_VALUE;    // means no value for this concept   next = NULL;   prev = NULL;}// Bulid a new concept based on the given concept, and add it to the// linked list. Copy all the features of the given concept.Concept::Concept(Concept *concept){   for(int x = 0; x < Version::num_dimensions; x++)      features[x] = concept->features[x];   next = concept->next;   prev = concept;   concept->next = this;   next->prev = this;}// Construct a concept that has the same features as the given exampleConcept::Concept(Example *example){   for(int x = 0; x < Version::num_dimensions; x++)      features[x] = example->get_value(x);   next = NULL;   prev = NULL;}// Delete dynamically allocated features array, and correct doubly-linked list.Concept::~Concept(){    next->prev = prev;    prev->next = next;}// Set one of the values of one of the attributes.void Concept::set_feature(int dim, int value){   features[dim] = value;}// A concept is consistent with an example if for each feature (conjunct) in// the concept, either the attribute of the feature is not mentioned in// the list of features describing the example, or, if it is mentioned,// the corresponding feature has the same attribute value. For instance,// if an example corresponds to an office on the third floor, then any// concept consistent with that example must either not mention a floor or// indicate the third floor.ConsistentType Concept::consistent(Example *example){   for(int x = 0; x < Version::num_dimensions; x++)      if(features[x] != NO_VALUE && example->get_value(x) != features[x])         return INCONSISTENT;   return CONSISTENT;}// For the restricted hypothesis space consisting of conjunctions of positive// literals, generalization corresponds to removing features from a concept// represented as a conjunction of features.void Concept::generalize(){   Concept *concept;   for(int x = 0; x < Version::num_dimensions; x++)      if(features[x] != NO_VALUE) {         concept = new Concept(this);  // Adds it to the linked list         concept->set_feature(x, NO_VALUE);      }}// Minimally specialize this concept. Add new concepts to the boundary.void Concept::specialize(){   Concept *temp;   for(int dim = 0; dim < Version::num_dimensions; dim++)	if(features[dim] == NO_VALUE)   // Only if consistent	  for(int v = 0; v < Version::dimensions[dim].num_values; v++) {	    temp = new Concept(this);   // Adds it to the linked list	    temp->set_feature(dim, v);  // Adds the new feature	  }}// Is this class a generalization of the given class? If so, return TRUE.int Concept::is_generalization_of(Concept *concept){   for(int x = 0; x < Version::num_dimensions; x++)      if(features[x] != NO_VALUE && concept->features[x] != features[x])         return 0;   return 1;}// Print this conceptostream& operator<<(ostream &o, Concept &c){  o << "( ";  for(int x = 0; x < Version::num_dimensions; x++)    if(c.features[x] != NO_VALUE)      o << Version::dimensions[x].values[c.features[x]] << " ";  o << ")";  return o;}/* * Copyright 1994, Brown University, Providence, RI * * Permission to use and modify this software and its documentation for * any purpose other than its incorporation into a commercial product is * hereby granted without fee.  Permission to copy and distribute this * software and its documentation only for non-commercial use is also * granted without fee, provided, however, that the above copyright notice * appear in all copies, that both that copyright notice and this permission * notice appear in supporting documentation, that the name of Brown * University not be used in advertising or publicity pertaining to * distribution of the software without specific, written prior permission, * and that the person doing the distribution notify Brown University of * such distributions outside of his or her organization. Brown University * makes no representations about the suitability of this software for * any purpose.  It is provided "as is" without express or implied warranty. * Brown University requests notification of any modifications to this * software or its documentation. * * Send the following redistribution information: * *	Name: *	Organization: *	Address (postal and/or electronic): * * To: *	Software Librarian *	Computer Science Department, Box 1910 *	Brown University *	Providence, RI 02912 * *		or * *	brusd@cs.brown.edu * * We will acknowledge all electronic notifications. */