public double CalculateMinimumFinalProbability(AutoResizeBigVector <double> cache, PrecalculatedTransitionTarget[] precalculatedTransitionTargets, double[] initialStateProbabilities)
{
var cid = Ltmdp.GetRootContinuationGraphLocationOfInitialState();
cache?.Clear(cid); //use cid as offset, because it is the smallest element
return(CalculateMinimumProbabilityOfCid(cache, precalculatedTransitionTargets, initialStateProbabilities, cid));
}
internal double CalculateMaximumFinalProbability(AutoResizeBigVector <double> cache, double[] initialStateProbabilities)
{
var cid = Nmdp.GetRootContinuationGraphLocationOfInitialState();
cache?.Clear(cid); //use cid as offset, because it is the smallest element
return(CalculateMaximumProbabilityOfCid(cache, initialStateProbabilities, cid));
}
private double CalculateMaximumProbabilityOfCid(AutoResizeBigVector <double> cache, double[] stateProbabilities, long currentCid)
{
if (cache != null && HasCacheEntry(cache, currentCid))
{
return(cache[(int)currentCid]);
}
var result = double.NaN;
NestedMarkovDecisionProcess.ContinuationGraphElement cge = Nmdp.GetContinuationGraphElement(currentCid);
if (cge.IsChoiceTypeUnsplitOrFinal)
{
var cgl = Nmdp.GetContinuationGraphLeaf(currentCid);
result = stateProbabilities[cgl.ToState];
}
else
{
var cgi = Nmdp.GetContinuationGraphInnerNode(currentCid);
if (cge.IsChoiceTypeForward)
{
// Note, cgi.Probability is used in the branch "else if (cge.IsChoiceTypeProbabilitstic)"
result = CalculateMaximumProbabilityOfCid(cache, stateProbabilities, cgi.FromCid);
}
if (cge.IsChoiceTypeNondeterministic)
{
var biggest = double.NegativeInfinity;
for (var i = cgi.FromCid; i <= cgi.ToCid; i++)
{
var resultOfChild = CalculateMaximumProbabilityOfCid(cache, stateProbabilities, i);
if (resultOfChild > biggest)
{
biggest = resultOfChild;
}
}
result = biggest;
}
else if (cge.IsChoiceTypeProbabilitstic)
{
var sum = 0.0;
for (var i = cgi.FromCid; i <= cgi.ToCid; i++)
{
var transitionProbability = Nmdp.GetContinuationGraphElement(i).Probability;
var resultOfChild = CalculateMaximumProbabilityOfCid(cache, stateProbabilities, i);
sum += transitionProbability * resultOfChild;
}
result = sum;
}
}
if (cache != null)
{
cache[(int)currentCid] = result;
}
return(result);
}
internal double[] MaximumIterator(AutoResizeBigVector <double> cache, Dictionary <int, bool> exactlyOneStates, Dictionary <int, bool> exactlyZeroStates, int steps)
{
var stopwatch = new Stopwatch();
stopwatch.Start();
var stateCount = Nmdp.States;
var xold = new double[stateCount];
var xnew = CreateDerivedVector(exactlyOneStates);
var loops = 0;
while (loops < steps)
{
// switch xold and xnew
var xtemp = xold;
xold = xnew;
xnew = xtemp;
loops++;
for (var i = 0; i < stateCount; i++)
{
if (exactlyOneStates.ContainsKey(i))
{
//we could remove this line, because already set by CreateDerivedVector and never changed when we initialize xold with CreateDerivedVector(directlySatisfiedStates)
xnew[i] = 1.0;
}
else if (exactlyZeroStates.ContainsKey(i))
{
//we could remove this line, because already set by CreateDerivedVector and never changed when we initialize xold with CreateDerivedVector(directlySatisfiedStates)
xnew[i] = 0.0;
}
else
{
var cid = Nmdp.GetRootContinuationGraphLocationOfState(i);
cache?.Clear(cid); //use cid as offset, because it is the smallest element
xnew[i] = CalculateMaximumProbabilityOfCid(cache, xold, cid);
}
}
if (loops % 10 == 0)
{
stopwatch.Stop();
var currentProbability = CalculateMaximumFinalProbability(cache, xnew);
_output?.WriteLine(
$"{loops} Bounded Until iterations in {stopwatch.Elapsed}. Current probability={currentProbability.ToString(CultureInfo.InvariantCulture)}");
stopwatch.Start();
}
}
stopwatch.Stop();
return(xnew);
}
internal double CalculateMaximumProbabilityToReachStateFormulaInBoundedSteps(Formula psi, int steps)
{
var cache = new AutoResizeBigVector <double> {
DefaultValue = double.NaN
};
var psiEvaluator = Nmdp.CreateFormulaEvaluator(psi);
var directlySatisfiedStates = CalculateSatisfiedStates(psiEvaluator);
var excludedStates = new Dictionary <int, bool>(); // change for \phi Until \psi
var xnew = MaximumIterator(cache, directlySatisfiedStates, excludedStates, steps);
var finalProbability = CalculateMaximumFinalProbability(cache, xnew);
return(finalProbability);
}
internal double[] MaximumIterator(AutoResizeBigVector <double> cache, PrecalculatedTransitionTarget[] precalculatedTransitionTargets, int steps)
{
var stopwatch = new Stopwatch();
stopwatch.Start();
var stateCount = Ltmdp.SourceStates.Count;
var xold = new double[stateCount];
var xnew = new double[stateCount];
var loops = 0;
while (loops < steps)
{
// switch xold and xnew
var xtemp = xold;
xold = xnew;
xnew = xtemp;
loops++;
for (var i = 0; i < stateCount; i++)
{
var cid = Ltmdp.GetRootContinuationGraphLocationOfState(i);
cache?.Clear(cid); //use cid as offset, because it is the smallest element
xnew[i] = CalculateMaximumProbabilityOfCid(cache, precalculatedTransitionTargets, xold, cid);
}
if (loops % 10 == 0)
{
stopwatch.Stop();
var currentProbability = CalculateMaximumFinalProbability(cache, precalculatedTransitionTargets, xnew);
_output?.WriteLine(
$"{loops} Bounded Until iterations in {stopwatch.Elapsed}. Current probability={currentProbability.ToString(CultureInfo.InvariantCulture)}");
stopwatch.Start();
}
}
stopwatch.Stop();
return(xnew);
}
private bool HasCacheEntry(AutoResizeBigVector <double> cache, long entry)
{
return(!double.IsNaN(cache[(int)entry]));
}
private double CalculateMaximumProbabilityOfCid(AutoResizeBigVector <double> cache, PrecalculatedTransitionTarget[] precalculatedTransitionTargets, double[] stateProbabilities, long currentCid)
{
if (cache != null && HasCacheEntry(cache, currentCid))
{
return(cache[(int)currentCid]);
}
var result = double.NaN;
LabeledTransitionMarkovDecisionProcess.ContinuationGraphElement cge = Ltmdp.GetContinuationGraphElement(currentCid);
if (cge.IsChoiceTypeUnsplitOrFinal)
{
var transitionTargetPosition = cge.To;
var transitionTarget = Ltmdp.GetTransitionTarget(transitionTargetPosition);
if (precalculatedTransitionTargets[transitionTargetPosition].HasFlag(PrecalculatedTransitionTarget.Satisfied))
{
result = 1.0;
}
else if (precalculatedTransitionTargets[transitionTargetPosition].HasFlag(PrecalculatedTransitionTarget.Excluded))
{
result = 0.0;
}
else
{
result = stateProbabilities[transitionTarget.TargetState];
}
}
else
{
if (cge.IsChoiceTypeForward)
{
// Note, cgi.Probability is used in the branch "else if (cge.IsChoiceTypeProbabilitstic)"
result = CalculateMaximumProbabilityOfCid(cache, precalculatedTransitionTargets, stateProbabilities, cge.From);
}
if (cge.IsChoiceTypeNondeterministic)
{
var biggest = double.NegativeInfinity;
for (var i = cge.From; i <= cge.To; i++)
{
var resultOfChild = CalculateMaximumProbabilityOfCid(cache, precalculatedTransitionTargets, stateProbabilities, i);
if (resultOfChild > biggest)
{
biggest = resultOfChild;
}
}
result = biggest;
}
else if (cge.IsChoiceTypeProbabilitstic)
{
var sum = 0.0;
for (var i = cge.From; i <= cge.To; i++)
{
var transitionProbability = Ltmdp.GetContinuationGraphElement(i).Probability;
var resultOfChild = CalculateMaximumProbabilityOfCid(cache, precalculatedTransitionTargets, stateProbabilities, i);
sum += transitionProbability * resultOfChild;
}
result = sum;
}
}
if (cache != null)
{
cache[(int)currentCid] = result;
}
return(result);
}
