public override IEnumerable <Path <SS, DS> > Compute(SS ss, DS ds, Goal <SS, DS> Goal, Operator <SS, DS>[] Ops)
{
this.init(ss, ds, Ops, Goal);
ExtendedDictionary <DS, Metric> H1 = new ExtendedDictionary <DS, Metric>(x => aS.h(x, aS.Sgoal));
ExtendedDictionary <DS, DS> tree = new ExtendedDictionary <DS, DS>(x => null);
Path <SS, DS> Incumbant = null;
int GlobalSearchLimit = GetGlobalSearchComputationLimit( );
this.aS.ComputationLimit = GlobalSearchLimit;
int LocalSearchLimit = GetLocalSearchComputationLimit( );
foreach (Path <SS, DS> p in AnytimeDStarLiteLookahead(aS, GlobalSearchLimit))
{
this.Expansions += aS.Expansions;
this.Generations += aS.Generations;
aS.Expansions = 0;
aS.Generations = 0;
if (p == null)
{
switch (sm)
{
/*case ChooseMethodStep.LRTAStar:
* yield return LRTAStar<SS, DS>.AStarLookAhead( ss.InitialDynamicState, ss,
* LocalSearchLimit, aS.sv,
* ref this.Expansions, ref this.Generations, false,
* Ops, H1, H, Goal, Metric.One, false );
* break;
* case ChooseMethodStep.RTAStar:
* yield return LRTAStar<SS, DS>.AStarLookAhead( ss.InitialDynamicState, ss,
* LocalSearchLimit, aS.sv,
* ref this.Expansions, ref this.Generations, false,
* Ops, H1, H, Goal, Metric.One, true );
* break;*/
case ChooseMethodStep.LSSLRTAStar:
yield return(LSSLRTAStar <SS, DS> .LSSLRTAStarLookahead(LocalSearchLimit, ss, aS.Sstart,
aS.Sgoal, Ops, aS.h, ref Incumbant, ref this.Expansions, aS.sv, tree, H1));
break;
}
}
else
{
yield return(p);
}
aS.Sstart = aS.ss.InitialDynamicState;
}
yield break;
}
private Path <SS, DS> ChooseStep( )
{
try {
if (!ComputeShortestPathNormalTermination && !rhs(Sstart).Equals(Metric.PositiveInfinity))
{
var ret = this.ExtractPath( );
(this.sv as OpenGLStateVisualizer).Global = true;
return(ret);
}
else
{
(this.sv as OpenGLStateVisualizer).Global = false;
if (sm.Equals(ChooseMethodStep.Null))
{
return(null);
}
/// Choose a landmark goal state to step towards.
DS LandmarkGoal = null;
switch (lgm)
{
case ChooseMethodLandMarkGoal.UTop:
LandmarkGoal = U.Top( );
break;
case ChooseMethodLandMarkGoal.USample:
LandmarkGoal = Nearest(Sstart, us);
break;
case ChooseMethodLandMarkGoal.Goal:
LandmarkGoal = Sgoal;
break;
}
if (LandmarkGoal == null)
{
return(null);
}
/// Choose the successor nodes we want to consider to move toward.
IEnumerable <DS> succ = null;
bool LLR = false;
switch (fsm)
{
case ChooseMethodFilterSucc.All:
succ = Succ(Sstart);
break;
case ChooseMethodFilterSucc.Lock:
succ = Succ(Sstart);
if (succ == null)
{
break;
}
succ = succ.Where(st => !this.LockedList.Contains(st));
if (succ.Count( ) == 0)
{
succ = Succ(Sstart);
LLR = true;
LockedList.Add(Sstart);
}
// Test if should add to dead end list.
if (succ.Where(st => !this.LockedList.Contains(st)).All(
ds => h(ds, LandmarkGoal) > h(Sstart, LandmarkGoal)))
{
LockedList.Add(Sstart);
}
break;
}
if (succ == null)
{
return(null);
}
/// Choose the state we want to step towards.
DS next = null;
switch (sm)
{
case ChooseMethodStep.MinHLandmarkGoal:
this.Expansions++;
this.Generations += (uint)succ.Count( );
next = succ.ArgMin(ds => h(ds, LandmarkGoal));
break;
case ChooseMethodStep.MinHAdustedLandmarkGoal:
this.Expansions++;
this.Generations += (uint)succ.Count( );
Metric minV = null;
foreach (var s in succ)
{
Metric h = hAdjusted(s, Sgoal);
if (minV == null || (h != null && minV > h))
{
minV = h;
next = s;
}
}
// Update hAdjusted for current state.
if (minV != null)
{
hAdjusted(Sstart, minV + h(next, Sstart));
}
break;
/*case ChooseMethodStep.LRTAStar:
* int Expansions = GetLocalSearchComputationLimit( );
* var P = LRTAStar<SS, DS>.AStarLookAhead( ss.InitialDynamicState, ss,
* Expansions, sv,
* ref this.Expansions, ref this.Generations, false,
* Ops, HAdjusted, H, new InStateGoal<SS, DS>( LandmarkGoal ), Weight, false );
* if ( P == null ) {
* next = null;
* } else {
* next = P.Actions.First.Value.PerformOn( Sstart, ss ).First( );
* }
* break;
* case ChooseMethodStep.RTAStar:
* Expansions = GetLocalSearchComputationLimit( );
* P = LRTAStar<SS, DS>.AStarLookAhead( ss.InitialDynamicState, ss,
* Expansions, sv,
* ref this.Expansions, ref this.Generations, false,
* Ops, HAdjusted, H, new InStateGoal<SS, DS>( LandmarkGoal ), Weight, true );
* if ( P == null ) {
* next = null;
* } else {
* next = P.Actions.First.Value.PerformOn( Sstart, ss ).First( );
* }
* break;
* case ChooseMethodStep.AStar:
* Expansions = GetLocalSearchComputationLimit( );
* P = LRTAStar<SS, DS>.AStarLookAhead( ss.InitialDynamicState, ss,
* Expansions, sv,
* ref this.Expansions, ref this.Generations, false,
* Ops, null, H, new InStateGoal<SS, DS>( LandmarkGoal ), Weight, false );
* if ( P == null ) {
* next = null;
* } else {
* next = P.Actions.First.Value.PerformOn( Sstart, ss ).First( );
* }
* break;*/
case ChooseMethodStep.LSSLRTAStar:
int Expansions = GetLocalSearchComputationLimit( );
var P = LSSLRTAStar <SS, DS> .LSSLRTAStarLookahead(Expansions, ss, Sstart,
Sgoal, Ops, h0, ref Incumbant, ref this.Expansions, sv, tree, HLSS);
if (P == null)
{
next = null;
}
else
{
next = P.Actions.First.Value.PerformOn(Sstart, ss).First( );
}
break;
}
if (next == null)
{
return(null);
}
if (LLR)
{
LockedList.Remove(next);
LLR = false;
}
/// Extract the path info.
Operator <SS, DS> Op = null;
foreach (var action in Ops)
{
if (action.IsValidOn(Sstart, ss, false) && action.PerformOn(Sstart, ss).First( ).Equals(next))
{
Op = action;
break;
}
}
if (Op == null)
{
return(null);
}
else
{
return(Operator <SS, DS> .MakePath(Op));
}
}
} catch (InvalidOperationException) {
return(null);
}
}