public ICategoricalDistribution jointDistribution(params IProposition[] propositions)
{
ProbabilityTable d = null;
IProposition conjProp = ProbUtil.constructConjunction(propositions);
ISet <IRandomVariable> vars = CollectionFactory.CreateSet <IRandomVariable>(conjProp.getUnboundScope());
if (vars.Size() > 0)
{
IRandomVariable[] distVars = vars.ToArray();
ProbabilityTable ud = new ProbabilityTable(distVars);
object[] values = new object[vars.Size()];
ProbabilityTable.ProbabilityTableIterator di = new ProbabilityTableIterator(conjProp, ud, values, vars);
distribution.iterateOverTable(di);
d = ud;
}
else
{
// No Unbound Variables, therefore just return
// the singular probability related to the proposition.
d = new ProbabilityTable();
d.setValue(0, prior(propositions));
}
return(d);
}
public virtual ICategoricalDistribution posteriorDistribution(IProposition phi, params IProposition[] evidence)
{
IProposition conjEvidence = ProbUtil.constructConjunction(evidence);
// P(A | B) = P(A AND B)/P(B) - (13.3 AIMA3e)
ICategoricalDistribution dAandB = jointDistribution(phi, conjEvidence);
ICategoricalDistribution dEvidence = jointDistribution(conjEvidence);
ICategoricalDistribution rVal = dAandB.divideBy(dEvidence);
// Note: Need to ensure normalize() is called
// in order to handle the case where an approximate
// algorithm is used (i.e. won't evenly divide
// as will have calculated on separate approximate
// runs). However, this should only be done
// if the all of the evidences scope are bound (if not
// you are returning in essence a set of conditional
// distributions, which you do not want normalized).
bool unboundEvidence = false;
foreach (IProposition e in evidence)
{
if (e.getUnboundScope().Size() > 0)
{
unboundEvidence = true;
break;
}
}
if (!unboundEvidence)
{
rVal.normalize();
}
return(rVal);
}
public CategoricalDistributionIteratorJointDistribution(IProposition conjProp, ISet <IRandomVariable> vars, ProbabilityTable ud, object[] values)
{
this.conjProp = conjProp;
this.vars = vars;
this.ud = ud;
this.values = values;
}
public virtual ICategoricalDistribution jointDistribution(params IProposition[] propositions)
{
ProbabilityTable d = null;
IProposition conjProp = ProbUtil.constructConjunction(propositions);
ISet <IRandomVariable> vars = CollectionFactory.CreateSet <IRandomVariable>(conjProp.getUnboundScope());
if (vars.Size() > 0)
{
IRandomVariable[] distVars = new IRandomVariable[vars.Size()];
int i = 0;
foreach (IRandomVariable rv in vars)
{
distVars[i] = rv;
++i;
}
ProbabilityTable ud = new ProbabilityTable(distVars);
object[] values = new object[vars.Size()];
CategoricalDistributionIterator di = new CategoricalDistributionIteratorJointDistribution(conjProp, vars, ud, values);
IRandomVariable[] X = conjProp.getScope().ToArray();
bayesInference.Ask(X, new AssignmentProposition[0], bayesNet).iterateOver(di);
d = ud;
}
else
{
// No Unbound Variables, therefore just return
// the singular probability related to the proposition.
d = new ProbabilityTable();
d.setValue(0, prior(propositions));
}
return(d);
}
public ProbabilityTableIterator(IProposition conjProp, ProbabilityTable ud, object[] values, ISet <IRandomVariable> vars)
{
this.conjProp = conjProp;
this.ud = ud;
this.values = values;
this.vars = vars;
}
public ExistsFutureProposition(int numStates, IProposition f)
{
this.numStates = numStates;
this.f = f;
// EF(f) === E[true U f]
this.existsUntil = new ExistsUntilProposition(numStates, TrueProposition.Instance, f);
}
public GraphNode(int _currentNode, GraphNode _parentNode, IProposition _type, StreamWriter writer)
{
this.currentNode = _currentNode;
this.propositionType = _type;
this.sw = writer;
this.parentNode = _parentNode;
processNode();
}
public CategoricalDistributionIteratorImpl(IFiniteProbabilityModel transitionModel, IMap <IRandomVariable, AssignmentProposition> xtVarAssignMap, ICategoricalDistribution s1, IProposition xtp1, AssignmentProposition[] xt)
{
this.transitionModel = transitionModel;
this.xtVarAssignMap = xtVarAssignMap;
this.s1 = s1;
this.xtp1 = xtp1;
this.xt = xt;
}
private double probabilityOf(IProposition phi)
{
double[] probSum = new double[1];
ProbabilityTable.ProbabilityTableIterator di = new ProbabilityTableIteratorImpl2(probSum, phi);
distribution.iterateOverTable(di);
return(probSum[0]);
}
public AllGlobalProposition(int numStates, IProposition f)
{
this.f = f;
// AG(f) === !EF(!f)
var notF = new NotProposition(f);
this.existsFuture = new ExistsFutureProposition(numStates, notF);
}
public CategoricalDistributionIteratorImpl2(IMap <IRandomVariable, AssignmentProposition> x_kp1VarAssignMap, IFiniteProbabilityModel sensorModel, IFiniteProbabilityModel transitionModel, ICategoricalDistribution b_kp1t, IProposition pe_kp1, IProposition xk, IProposition x_kp1)
{
this.x_kp1VarAssignMap = x_kp1VarAssignMap;
this.sensorModel = sensorModel;
this.transitionModel = transitionModel;
this.b_kp1t = b_kp1t;
this.pe_kp1 = pe_kp1;
this.xk = xk;
this.x_kp1 = x_kp1;
}
public ICategoricalDistribution posteriorDistribution(IProposition phi,
params IProposition[] evidence)
{
IProposition conjEvidence = ProbUtil.constructConjunction(evidence);
// P(A | B) = P(A AND B)/P(B) - (13.3 AIMA3e)
ICategoricalDistribution dAandB = jointDistribution(phi, conjEvidence);
ICategoricalDistribution dEvidence = jointDistribution(conjEvidence);
return(dAandB.divideBy(dEvidence));
}
public CategoricalDistribution posteriorDistribution(IProposition phi,
params IProposition[] evidence)
{
IProposition conjEvidence = ProbUtil.constructConjunction(evidence);
// P(A | B) = P(A AND B)/P(B) - (13.3 AIMA3e)
CategoricalDistribution dAandB = jointDistribution(phi, conjEvidence);
CategoricalDistribution dEvidence = jointDistribution(conjEvidence);
return dAandB.divideBy(dEvidence);
}
public NotProposition(IProposition prop)
{
if (null == prop)
{
throw new IllegalArgumentException("Proposition to be negated must be specified.");
}
// Track nested scope
addScope(prop.getScope());
addUnboundScope(prop.getUnboundScope());
proposition = prop;
}
//
// START-ProbabilityModel
public virtual bool isValid()
{
// Handle rounding
int counter = 0;
IProposition[] propositionArray = new IProposition[representation.Size()];
foreach (IProposition prop in representation)
{
propositionArray[counter] = prop;
++counter;
}
return(System.Math.Abs(1 - prior(propositionArray)) <= ProbabilityModelImpl.DEFAULT_ROUNDING_THRESHOLD);
}
public virtual double posterior(IProposition phi, params IProposition[] evidence)
{
IProposition conjEvidence = ProbUtil.constructConjunction(evidence);
// P(A | B) = P(A AND B)/P(B) - (13.3 AIMA3e)
IProposition aAndB = new ConjunctiveProposition(phi, conjEvidence);
double probabilityOfEvidence = prior(conjEvidence);
if (0 != probabilityOfEvidence)
{
return(prior(aAndB) / probabilityOfEvidence);
}
return(0);
}
public double posterior(IProposition phi, params IProposition[] evidence)
{
IProposition conjEvidence = ProbUtil.constructConjunction(evidence);
// P(A | B) = P(A AND B)/P(B) - (13.3 AIMA3e)
IProposition aAndB = new ConjunctiveProposition(phi, conjEvidence);
double probabilityOfEvidence = prior(conjEvidence);
if (0 != probabilityOfEvidence)
{
return prior(aAndB)/probabilityOfEvidence;
}
return 0;
}
// END-FiniteProbabilityModel
//
//
// PRIVATE METHODS
//
private double probabilityOf(IProposition phi)
{
double[] probSum = new double[1];
//ProbabilityTable.Iterator di = new ProbabilityTable.Iterator() {
// public void iterate(Map<RandomVariable, Object> possibleWorld,
// double probability) {
// if (phi.holds(possibleWorld)) {
// probSum[0] += probability;
// }
// }
//};
//distribution.iterateOverTable(di);
// TODO
return(probSum[0]);
}
public CategoricalDistribution jointDistribution(
params IProposition[] propositions)
{
ProbabilityTable d = null;
IProposition conjProp = ProbUtil
.constructConjunction(propositions);
LinkedHashSet <RandomVariable> vars = new LinkedHashSet <RandomVariable>(
conjProp.getUnboundScope());
if (vars.Count > 0)
{
RandomVariable[] distVars = new RandomVariable[vars.Count];
vars.CopyTo(distVars);
ProbabilityTable ud = new ProbabilityTable(distVars);
Object[] values = new Object[vars.Count];
//ProbabilityTable.Iterator di = new ProbabilityTable.Iterator() {
// public void iterate(Map<RandomVariable, Object> possibleWorld,
// double probability) {
// if (conjProp.holds(possibleWorld)) {
// int i = 0;
// for (RandomVariable rv : vars) {
// values[i] = possibleWorld.get(rv);
// i++;
// }
// int dIdx = ud.getIndex(values);
// ud.setValue(dIdx, ud.getValues()[dIdx] + probability);
// }
// }
//};
//distribution.iterateOverTable(di);
// TODO:
d = ud;
}
else
{
// No Unbound Variables, therefore just return
// the singular probability related to the proposition.
d = new ProbabilityTable();
d.setValue(0, prior(propositions));
}
return(d);
}
/// <summary>
/// Gets the best (lowest cost) relevant action node satisfying the given proposition during the FF evaluation.
/// </summary>
/// <param name="proposition">Proposition to satisfy.</param>
/// <param name="actionLayer">Action layer.</param>
/// <returns>Best relevant action node.</returns>
private static ActionNode GetBestRelevantActionNodeFF(IProposition proposition, ActionLayer actionLayer)
{
ActionNode bestActionNode = null;
foreach (var actionNode in actionLayer)
{
if (actionNode.Successors.Contains(proposition))
{
if (bestActionNode == null || actionNode.Operator.GetCost() < bestActionNode.Operator.GetCost())
{
bestActionNode = actionNode;
}
}
}
return(bestActionNode);
}
public virtual double prior(params IProposition[] phi)
{
// Calculating the prior, therefore no relevant evidence
// just query over the scope of proposition phi in order
// to get a joint distribution for these
IProposition conjunct = ProbUtil.constructConjunction(phi);
IRandomVariable[] X = conjunct.getScope().ToArray();
ICategoricalDistribution d = bayesInference.Ask(X, new AssignmentProposition[0], bayesNet);
// Then calculate the probability of the propositions phi
// be seeing where they hold.
double[] probSum = new double[1];
CategoricalDistributionIterator di = new CategoricalDistributionIteraorPrior(conjunct, probSum);
d.iterateOver(di);
return(probSum[0]);
}
public DisjunctiveProposition(IProposition left, IProposition right)
{
if (null == left)
{
throw new IllegalArgumentException("Left side of disjunction must be specified.");
}
if (null == right)
{
throw new IllegalArgumentException("Right side of disjunction must be specified.");
}
// Track nested scope
addScope(left.getScope());
addScope(right.getScope());
addUnboundScope(left.getUnboundScope());
addUnboundScope(right.getUnboundScope());
this.left = left;
this.right = right;
}
public ICategoricalDistribution forward(ICategoricalDistribution f1_t, ICollection <AssignmentProposition> e_tp1)
{
ICategoricalDistribution s1 = new ProbabilityTable(f1_t.getFor());
// Set up required working variables
IProposition[] props = new IProposition[s1.getFor().Size()];
int i = 0;
foreach (IRandomVariable rv in s1.getFor())
{
props[i] = new RandVar(rv.getName(), rv.getDomain());
++i;
}
IProposition Xtp1 = ProbUtil.constructConjunction(props);
AssignmentProposition[] xt = new AssignmentProposition[tToTm1StateVarMap.Size()];
IMap <IRandomVariable, AssignmentProposition> xtVarAssignMap = CollectionFactory.CreateInsertionOrderedMap <IRandomVariable, AssignmentProposition>();
i = 0;
foreach (IRandomVariable rv in tToTm1StateVarMap.GetKeys())
{
xt[i] = new AssignmentProposition(tToTm1StateVarMap.Get(rv), "<Dummy Value>");
xtVarAssignMap.Put(rv, xt[i]);
++i;
}
// Step 1: Calculate the 1 time step prediction
// ∑<sub>x<sub>t</sub></sub>
CategoricalDistributionIterator if1_t = new CategoricalDistributionIteratorImpl(transitionModel,
xtVarAssignMap, s1, Xtp1, xt);
f1_t.iterateOver(if1_t);
// Step 2: multiply by the probability of the evidence
// and normalize
// <b>P</b>(e<sub>t+1</sub> | X<sub>t+1</sub>)
ICategoricalDistribution s2 = sensorModel.posteriorDistribution(ProbUtil
.constructConjunction(e_tp1.ToArray()), Xtp1);
return(s2.multiplyBy(s1).normalize());
}
public ConjunctiveProposition(IProposition left, IProposition right)
{
if (null == left)
{
throw new IllegalArgumentException(
"Left side of conjunction must be specified.");
}
if (null == right)
{
throw new IllegalArgumentException(
"Right side of conjunction must be specified.");
}
// Track nested scope
addScope(left.getScope());
addScope(right.getScope());
addUnboundScope(left.getUnboundScope());
addUnboundScope(right.getUnboundScope());
this.left = left;
this.right = right;
}
public ICategoricalDistribution backward(ICategoricalDistribution b_kp2t, ICollection <AssignmentProposition> e_kp1)
{
ICategoricalDistribution b_kp1t = new ProbabilityTable(b_kp2t.getFor());
// Set up required working variables
IProposition[] props = new IProposition[b_kp1t.getFor().Size()];
int i = 0;
foreach (IRandomVariable rv in b_kp1t.getFor())
{
IRandomVariable prv = tToTm1StateVarMap.Get(rv);
props[i] = new RandVar(prv.getName(), prv.getDomain());
++i;
}
IProposition Xk = ProbUtil.constructConjunction(props);
AssignmentProposition[] ax_kp1 = new AssignmentProposition[tToTm1StateVarMap.Size()];
IMap <IRandomVariable, AssignmentProposition> x_kp1VarAssignMap = CollectionFactory.CreateInsertionOrderedMap <IRandomVariable, AssignmentProposition>();
i = 0;
foreach (IRandomVariable rv in b_kp1t.getFor())
{
ax_kp1[i] = new AssignmentProposition(rv, "<Dummy Value>");
x_kp1VarAssignMap.Put(rv, ax_kp1[i]);
++i;
}
IProposition x_kp1 = ProbUtil.constructConjunction(ax_kp1);
props = e_kp1.ToArray();
IProposition pe_kp1 = ProbUtil.constructConjunction(props);
// ∑<sub>x<sub>k+1</sub></sub>
CategoricalDistributionIterator ib_kp2t = new CategoricalDistributionIteratorImpl2(x_kp1VarAssignMap,
sensorModel, transitionModel, b_kp1t, pe_kp1, Xk, x_kp1);
b_kp2t.iterateOver(ib_kp2t);
return(b_kp1t);
}
public SemanticTableux(IProposition ip, int _curNode, List <IProposition> toDraw)
{
isClosedNode = false;
graphviz = "";
displayThisNode = new List <string>();
currentNode = _curNode;
toBeProcessedProposition = ip;
leftProducts = new List <IProposition>();
rightProducts = new List <IProposition>();
nextNodes.Add(this);
isSplit = isSplitOrNot();
displayThisNode.Add(toBeProcessedProposition.GetString());
if (toDraw != null)
{
foreach (IProposition pp in toDraw)
{
displayThisNode.Add(pp.GetString());
}
}
DrawThisNode();
DrawGraph();
}
/**
* Unlike unconditional or prior probabilities, most of the time we have
* some information, usually called evidence, that has already been
* revealed. This is the conditional or posterior probability (or just
* "posterior" for short). Mathematically speaking, conditional
* probabilities are defined in terms of unconditional probabilities as
* follows, for any propositions a and b, we have:<br>
* <br>
* P(a | b) = P(a AND b)/P(b)<br>
* <br>
* which holds whenever P(b) > 0. Refer to equation 13.3 page 485 of AIMA3e.
* This can be rewritten in a different form called the <b>product rule</b>: <br>
* <br>
* P(a AND b) = P(a | b)P(b)<br>
* <br>
* and also as:<br>
* <br>
* P(a AND b) = P(b | a)P(a)<br>
* <br>
* whereby, equating the two right-hand sides and dividing by P(a) gives you
* Bayes' rule:<br>
* <br>
* P(b | a) = (P(a | b)P(b))/P(a) - i.e. (likelihood * prior)/evidence
*
* @param phi
* the proposition for which a probability value is to be
* returned.
* @param evidence
* information we already have.
* @return the probability of the proposition φ given evidence.
*/
protected abstract double posterior(IProposition phi, params IProposition[] evidence);
/** * Unlike unconditional or prior probabilities, most of the time we have * some information, usually called evidence, that has already been * revealed. This is the conditional or posterior probability (or just * "posterior" for short). Mathematically speaking, conditional * probabilities are defined in terms of unconditional probabilities as * follows, for any propositions a and b, we have:<br> * <br> * P(a | b) = P(a AND b)/P(b)<br> * <br> * which holds whenever P(b) > 0. Refer to equation 13.3 page 485 of AIMA3e. * This can be rewritten in a different form called the <b>product rule</b>: <br> * <br> * P(a AND b) = P(a | b)P(b)<br> * <br> * and also as:<br> * <br> * P(a AND b) = P(b | a)P(a)<br> * <br> * whereby, equating the two right-hand sides and dividing by P(a) gives you * Bayes' rule:<br> * <br> * P(b | a) = (P(a | b)P(b))/P(a) - i.e. (likelihood * prior)/evidence * * @param phi * the proposition for which a probability value is to be * returned. * @param evidence * information we already have. * @return the probability of the proposition φ given evidence. */ protected abstract double posterior(IProposition phi, params IProposition[] evidence);
public AndProposition(IProposition f, IProposition g)
{
this.f = f;
this.g = g;
}
/**
* Get a conditional distribution. Example:<br>
* <br>
* <b>P</b>(X | Y) gives the values of P(X = x<sub>i</sub> | Y =
* y<sub>j</sub>) for each possible i, j pair.
*
* @param phi
* the proposition for which a probability distribution is to be
* returned.
* @param evidence
* information we already have.
* @return the conditional distribution for <b>P</b>(φ | evidence).
*/
private CategoricalDistribution posteriorDistribution(IProposition phi,
params IProposition[] evidence);
//
// PRIVATE METHODS
//
private static IProposition constructConjunction(IProposition[] props, int idx)
{
if ((idx + 1) == props.Length)
{
return props[idx];
}
return new ConjunctiveProposition(props[idx], constructConjunction(
props, idx + 1));
}
/**
* Convenience method for ensure a conjunction of probabilistic
* propositions.
*
* @param props
* propositions to be combined into a ConjunctiveProposition if
* necessary.
* @return a ConjunctivePropositions if more than 1 proposition in 'props',
* otherwise props[0].
*/
public static IProposition constructConjunction(IProposition[] props)
{
return constructConjunction(props, 0);
}
public ExistsUntilProposition(int numStates, IProposition f, IProposition g)
{
this.f = f;
this.g = g;
this.values = new bool[numStates];
}
/**
* Get a conditional distribution. Example:<br>
* <br>
* <b>P</b>(X | Y) gives the values of P(X = x<sub>i</sub> | Y =
* y<sub>j</sub>) for each possible i, j pair.
*
* @param phi
* the proposition for which a probability distribution is to be
* returned.
* @param evidence
* information we already have.
* @return the conditional distribution for <b>P</b>(φ | evidence).
*/
private CategoricalDistribution posteriorDistribution(IProposition phi,
params IProposition[] evidence);
public bool isSplitOrNot()
{
IProposition propositionOfNotClass = toBeProcessedProposition.getChildProposition()[0];
List <IProposition> childPropositionsOfNot = propositionOfNotClass.getChildProposition();
if (toBeProcessedProposition is NotClass)
{
if (propositionOfNotClass is ImplicationClass || propositionOfNotClass is OrClass)
{
if (propositionOfNotClass is ImplicationClass)
{
leftProducts.Add(childPropositionsOfNot[0]);
rightProducts.Add(new NotClass(childPropositionsOfNot[1]));
}
else
{
leftProducts.Add(new NotClass(childPropositionsOfNot[0]));
rightProducts.Add(new NotClass(childPropositionsOfNot[1]));
}
ruleOfNode = Rule.Alpha;
return(false);
}
else if (propositionOfNotClass is NotClass)
{
ruleOfNode = Rule.Alpha;
leftProducts.Add(childPropositionsOfNot[0]);
return(false);
}
else if (propositionOfNotClass is FinalVar)
{
return(false);
}
else //andClass
{
ruleOfNode = Rule.Beta;
leftProducts.Add(new NotClass(childPropositionsOfNot[0]));
rightProducts.Add(new NotClass(childPropositionsOfNot[1]));
return(true);
}
}
else
{
if (toBeProcessedProposition is AndClass)
{
ruleOfNode = Rule.Alpha;
leftProducts.Add(childPropositionsOfNot[0]);
rightProducts.Add(childPropositionsOfNot[1]);
return(false);
}
else if (propositionOfNotClass is FinalVar)
{
return(false);
}
else //Orclass
{
ruleOfNode = Rule.Beta;
leftProducts.Add(childPropositionsOfNot[0]);
rightProducts.Add(childPropositionsOfNot[1]);
return(true);
}
}
}
// END-FiniteProbabilityModel
//
//
// PRIVATE METHODS
//
private double probabilityOf(IProposition phi)
{
double[] probSum = new double[1];
//ProbabilityTable.Iterator di = new ProbabilityTable.Iterator() {
// public void iterate(Map<RandomVariable, Object> possibleWorld,
// double probability) {
// if (phi.holds(possibleWorld)) {
// probSum[0] += probability;
// }
// }
//};
//distribution.iterateOverTable(di);
// TODO
return probSum[0];
}
/// <summary>
/// Checks whether the state layer has the specified proposition.
/// </summary>
/// <param name="proposition">Proposition.</param>
/// <returns>True if the state layer has the given proposition, false otherwise.</returns>
public bool HasProposition(IProposition proposition)
{
return(State.HasPredicate(((Proposition)proposition).Atom));
}
/// <summary>
/// Checks whether the state layer has the specified proposition.
/// </summary>
/// <param name="proposition">Proposition.</param>
/// <returns>True if the state layer has the given proposition, false otherwise.</returns>
public bool HasProposition(IProposition proposition)
{
return(State.HasValue(((Proposition)proposition).Assignment));
}
private static int GetGoalValue(IProposition goalProposition)
{
Fact relation = goalProposition.Name;
Term constant = relation.GetTerm(1);
return int.Parse(constant.ToString());
}
