public Model FindModelFor(String logicalSentence, int numberOfFlips,
double probabilityOfRandomWalk)
{
this.myModel = new Model();
var s = (Sentence) new PEParser().Parse(logicalSentence);
var transformer = new CNFTransformer();
var clauseGatherer = new CNFClauseGatherer();
var sc = new SymbolCollector();
var symbols = sc.GetSymbolsIn(s).ToList();
var r = new Random();
foreach (var sym in symbols)
{
this.myModel = this.myModel.Extend(sym, Util.RandomBoolean());
}
IList <Sentence> clauses = clauseGatherer.GetClausesFrom(transformer.Transform(s)).ToList();
//IList<Sentence> ClauseSet = new Converter<Sentence>().ListToSet(clauses);
lastClauses = clauses;
lastClausesFlip = new List <Int64>(clauses.Count + 1);
for (int i = 0; i < clauses.Count; i++)
{
lastClausesFlip.Add(0);
}
for (int i = 0; i < numberOfFlips; i++)
{
List <int> unsatList = new List <int>();
int numSat = this.GetNumberOfClausesSatisfiedIn(new Converter <Sentence>().ListToSet(clauses), myModel, unsatList);
if (numSat == clauses.Count)
{
trials = i;
return(myModel);
}
int probe = FindAnRandomUnsatisfiedClause(clauses, myModel, unsatList);
//Sentence clause = clauses[random.Next(clauses.Count)];
Sentence clause = clauses[probe];
lastClausesFlip[probe]++;
IList <Symbol> symbolsInClause = sc.GetSymbolsIn(clause).ToList();
if (random.NextDouble() >= probabilityOfRandomWalk)
{
Symbol randomSymbol = symbolsInClause[random.Next(symbolsInClause.Count)];
myModel = myModel.Flip(randomSymbol);
}
else
{
Symbol symbolToFlip = this.GetSymbolWhoseFlipMaximisesSatisfiedClauses(
new Converter <Sentence>().ListToSet(clauses),
symbolsInClause, myModel);
myModel = myModel.Flip(symbolToFlip);
}
}
trials = numberOfFlips;
return(null);
}
