protected internal virtual TransducerGraph BuildMinimizedFA()
{
TransducerGraph minimizedFA = new TransducerGraph();
TransducerGraph unminimizedFA = GetUnminimizedFA();
foreach (TransducerGraph.Arc arc in unminimizedFA.GetArcs())
{
ICollection <TransducerGraph.Arc> source = ProjectNode(arc.GetSourceNode());
ICollection <TransducerGraph.Arc> target = ProjectNode(arc.GetTargetNode());
try
{
if (minimizedFA.CanAddArc(source, target, arc.GetInput(), arc.GetOutput()))
{
minimizedFA.AddArc(source, target, arc.GetInput(), arc.GetOutput());
}
}
catch (Exception)
{
}
}
//throw new IllegalArgumentException();
minimizedFA.SetStartNode(ProjectNode(unminimizedFA.GetStartNode()));
foreach (object o in unminimizedFA.GetEndNodes())
{
minimizedFA.SetEndNode(ProjectNode(o));
}
return(minimizedFA);
}
public virtual TransducerGraph ProcessGraph(TransducerGraph g)
{
g = new TransducerGraph(g);
ISet nodes = g.GetNodes();
foreach (object node in nodes)
{
ICollection <TransducerGraph.Arc> myArcs = null;
if (forward)
{
myArcs = g.GetArcsBySource(node);
}
else
{
myArcs = g.GetArcsByTarget(node);
}
// compute a total
double total = 0.0;
foreach (TransducerGraph.Arc a in myArcs)
{
total += ((double)a.GetOutput());
}
// divide each by total
foreach (TransducerGraph.Arc a_1 in myArcs)
{
a_1.SetOutput(Math.Log(((double)a_1.GetOutput()) / total));
}
}
return(g);
}
// end static class ExactBlock
public static void Main(string[] args)
{
TransducerGraph fa = new TransducerGraph();
fa.AddArc(fa.GetStartNode(), "1", "a", string.Empty);
fa.AddArc(fa.GetStartNode(), "2", "b", string.Empty);
fa.AddArc(fa.GetStartNode(), "3", "c", string.Empty);
fa.AddArc("1", "4", "a", string.Empty);
fa.AddArc("2", "4", "a", string.Empty);
fa.AddArc("3", "5", "c", string.Empty);
fa.AddArc("4", "6", "c", string.Empty);
fa.AddArc("5", "6", "c", string.Empty);
fa.SetEndNode("6");
System.Console.Out.WriteLine(fa);
ExactAutomatonMinimizer minimizer = new ExactAutomatonMinimizer();
System.Console.Out.WriteLine(minimizer.MinimizeFA(fa));
System.Console.Out.WriteLine("Starting...");
Timing.StartTime();
TransducerGraph randomFA = TransducerGraph.CreateRandomGraph(100, 10, 1.0, 10, new ArrayList());
TransducerGraph minimizedRandomFA = minimizer.MinimizeFA(randomFA);
System.Console.Out.WriteLine(randomFA);
System.Console.Out.WriteLine(minimizedRandomFA);
Timing.Tick("done. ( " + randomFA.GetArcs().Count + " arcs to " + minimizedRandomFA.GetArcs().Count + " arcs)");
}
public virtual TransducerGraph MinimizeFA(TransducerGraph unminimizedFA)
{
this.unminimizedFA = unminimizedFA;
this.activePairs = Generics.NewLinkedList();
this.memberToBlock = Generics.NewHashMap();
Minimize();
return(BuildMinimizedFA());
}
public virtual TransducerGraph MinimizeFA(TransducerGraph unminimizedFA)
{
// System.out.println(unminimizedFA);
this.unminimizedFA = unminimizedFA;
this.splits = new ArrayList();
this.memberToBlock = new Hashtable();
//new IdentityHashMap(); // TEG: I had to change this b/c some weren't matching
Minimize();
return(BuildMinimizedFA());
}
public virtual TransducerGraph ProcessGraph(TransducerGraph graph)
{
// compute lambda function
ClassicCounter lambda = ComputeLambda(graph);
// not destructive
// do the pushing
TransducerGraph result = PushLambdas(graph, lambda);
// creates a new one
return(result);
}
public static TransducerGraph CreateGraphFromPaths <T>(ClassicCounter <IList <T> > pathCounter, int markovOrder)
{
TransducerGraph graph = new TransducerGraph();
// empty
foreach (IList <T> path in pathCounter.KeySet())
{
double count = pathCounter.GetCount(path);
AddOnePathToGraph(path, count, markovOrder, graph);
}
return(graph);
}
public static bool TestGraphPaths(TransducerGraph sourceGraph, TransducerGraph testGraph, int numPaths)
{
for (int i = 0; i < numPaths; i++)
{
IList path = sourceGraph.SampleUniformPathFromGraph();
double score = sourceGraph.GetOutputOfPathInGraph(path);
double newScore = testGraph.GetOutputOfPathInGraph(path);
if ((score - newScore) / (score + newScore) > 1e-10)
{
System.Console.Out.WriteLine("Problem: " + score + " vs. " + newScore + " on " + path);
return(false);
}
}
return(true);
}
/// <summary>Takes time linear in number of arcs.</summary>
public virtual TransducerGraph PushLambdas(TransducerGraph graph, ClassicCounter lambda)
{
TransducerGraph result = null;
result = graph.Clone();
// arcs have been copied too so we don't mess up graph
ICollection <TransducerGraph.Arc> arcs = result.GetArcs();
foreach (TransducerGraph.Arc arc in arcs)
{
double sourceLambda = lambda.GetCount(arc.GetSourceNode());
double targetLambda = lambda.GetCount(arc.GetTargetNode());
double oldOutput = ((double)arc.GetOutput());
double newOutput = oldOutput + targetLambda - sourceLambda;
arc.SetOutput(newOutput);
}
// do initialOutput
double startLambda = lambda.GetCount(result.GetStartNode());
if (startLambda != 0.0)
{
// add it back to the outbound arcs from start (instead of adding it to the initialOutput)
ICollection <TransducerGraph.Arc> startArcs = result.GetArcsBySource(result.GetStartNode());
foreach (TransducerGraph.Arc arc_1 in startArcs)
{
double oldOutput = ((double)arc_1.GetOutput());
double newOutput = oldOutput + startLambda;
arc_1.SetOutput(newOutput);
}
}
// do finalOutput
foreach (object o in result.GetEndNodes())
{
double endLambda = lambda.GetCount(o);
if (endLambda != 0.0)
{
// subtract it from the inbound arcs to end (instead of subtracting it from the finalOutput)
ICollection <TransducerGraph.Arc> endArcs = result.GetArcsByTarget(o);
foreach (TransducerGraph.Arc arc_1 in endArcs)
{
double oldOutput = ((double)arc_1.GetOutput());
double newOutput = oldOutput - endLambda;
arc_1.SetOutput(newOutput);
}
}
}
return(result);
}
/// <summary>For testing only.</summary>
public static void Main(string[] args)
{
IList pathList = new ArrayList();
TransducerGraph graph = CreateRandomGraph(1000, 10, 0.0, 10, pathList);
System.Console.Out.WriteLine("Done creating random graph");
PrintPathOutputs(pathList, graph, true);
System.Console.Out.WriteLine("Depth first search from start node");
StringBuilder b = new StringBuilder();
graph.DepthFirstSearch(true, b);
System.Console.Out.WriteLine(b.ToString());
b = new StringBuilder();
System.Console.Out.WriteLine("Depth first search back from end node");
graph.DepthFirstSearch(false, b);
System.Console.Out.WriteLine(b.ToString());
}
public static void Main(string[] args)
{
/*
* TransducerGraph fa = new TransducerGraph();
* fa.addArc(fa.getStartNode(),"1","a","");
* fa.addArc(fa.getStartNode(),"2","b","");
* fa.addArc(fa.getStartNode(),"3","c","");
* fa.addArc("1","4","a","");
* fa.addArc("2","4","a","");
* fa.addArc("3","5","c","");
* fa.addArc("4",fa.getEndNode(),"c","");
* fa.addArc("5",fa.getEndNode(),"c","");
* System.out.println(fa);
* ExactAutomatonMinimizer minimizer = new ExactAutomatonMinimizer();
* System.out.println(minimizer.minimizeFA(fa));
*/
System.Console.Out.WriteLine("Starting minimizer test...");
IList pathList = new ArrayList();
TransducerGraph randomFA = TransducerGraph.CreateRandomGraph(5000, 5, 1.0, 5, pathList);
IList outputs = randomFA.GetPathOutputs(pathList);
TransducerGraph.IGraphProcessor quasiDeterminizer = new QuasiDeterminizer();
IAutomatonMinimizer minimizer = new FastExactAutomatonMinimizer();
TransducerGraph.INodeProcessor ntsp = new TransducerGraph.SetToStringNodeProcessor(new PennTreebankLanguagePack());
TransducerGraph.IArcProcessor isp = new TransducerGraph.InputSplittingProcessor();
TransducerGraph.IArcProcessor ocp = new TransducerGraph.OutputCombiningProcessor();
TransducerGraph detGraph = quasiDeterminizer.ProcessGraph(randomFA);
TransducerGraph combGraph = new TransducerGraph(detGraph, ocp);
// combine outputs into inputs
TransducerGraph result = minimizer.MinimizeFA(combGraph);
// minimize the thing
System.Console.Out.WriteLine("Minimized from " + randomFA.GetNodes().Count + " to " + result.GetNodes().Count);
result = new TransducerGraph(result, ntsp);
// pull out strings from sets returned by minimizer
result = new TransducerGraph(result, isp);
// split outputs from inputs
IList minOutputs = result.GetPathOutputs(pathList);
System.Console.Out.WriteLine("Equal? " + outputs.Equals(minOutputs));
}
public static void Main(string[] args)
{
TransducerGraph.IGraphProcessor qd = new QuasiDeterminizer();
IList pathList = new ArrayList();
TransducerGraph graph = TransducerGraph.CreateRandomGraph(1000, 10, 1.0, 10, pathList);
StringBuilder b = new StringBuilder();
graph.DepthFirstSearch(true, b);
System.Console.Out.WriteLine(b.ToString());
System.Console.Out.WriteLine("Done creating random graph");
// TransducerGraph.printPathOutputs(pathList, graph, false);
//System.out.println("Depth first search from start node");
//TransducerGraph.depthFirstSearch(graph, TransducerGraph.END_NODE, new HashSet(), 0, false);
TransducerGraph newGraph = qd.ProcessGraph(graph);
System.Console.Out.WriteLine("Done quasi-determinizing");
//TransducerGraph.printPathOutputs(pathList, newGraph, false);
//System.out.println("Depth first search from start node");
//TransducerGraph.depthFirstSearch(newGraph, TransducerGraph.END_NODE, new HashSet(), 0, false);
TransducerGraph.TestGraphPaths(graph, newGraph, 1000);
}
/// <summary>For testing only.</summary>
private static void PrintPathOutputs(IList <IList> pathList, TransducerGraph graph, bool printPaths)
{
int i = 0;
foreach (IList path in pathList)
{
if (printPaths)
{
foreach (object aPath in path)
{
System.Console.Out.Write(aPath + " ");
}
}
else
{
System.Console.Out.Write(i++ + " ");
}
System.Console.Out.Write("output: " + graph.GetOutputOfPathInGraph(path));
System.Console.Out.WriteLine();
}
}
/// <summary>Takes time linear in number of arcs.</summary>
public static ClassicCounter ComputeLambda(TransducerGraph graph)
{
ArrayList queue = new ArrayList();
ClassicCounter lambda = new ClassicCounter();
ClassicCounter length = new ClassicCounter();
IDictionary first = new Hashtable();
ISet nodes = graph.GetNodes();
foreach (object node in nodes)
{
lambda.SetCount(node, 0);
length.SetCount(node, double.PositiveInfinity);
}
ISet endNodes = graph.GetEndNodes();
foreach (object o in endNodes)
{
lambda.SetCount(o, 0);
length.SetCount(o, 0);
queue.AddLast(o);
}
// Breadth first search
// get the first node from the queue
object node_1 = null;
try
{
node_1 = queue.RemoveFirst();
}
catch (NoSuchElementException)
{
}
while (node_1 != null)
{
double oldLen = length.GetCount(node_1);
ISet arcs = graph.GetArcsByTarget(node_1);
if (arcs != null)
{
foreach (object arc1 in arcs)
{
TransducerGraph.Arc arc = (TransducerGraph.Arc)arc1;
object newNode = arc.GetSourceNode();
IComparable a = (IComparable)arc.GetInput();
double k = ((double)arc.GetOutput());
double newLen = length.GetCount(newNode);
if (newLen == double.PositiveInfinity)
{
// we are discovering this
queue.AddLast(newNode);
}
IComparable f = (IComparable)first[newNode];
if (newLen == double.PositiveInfinity || (newLen == oldLen + 1 && a.CompareTo(f) < 0))
{
// f can't be null, since we have a newLen
// we do this to this to newNode when we have new info, possibly many times
first[newNode] = a;
// ejecting old one if necessary
length.SetCount(newNode, oldLen + 1);
// this may already be the case
lambda.SetCount(newNode, k + lambda.GetCount(node_1));
}
}
}
// get a new node from the queue
node_1 = null;
try
{
node_1 = queue.RemoveFirst();
}
catch (NoSuchElementException)
{
}
}
return(lambda);
}
// assumes that the path already has EPSILON as the last element.
public static void AddOnePathToGraph(IList path, double count, int markovOrder, TransducerGraph graph)
{
object source = graph.GetStartNode();
for (int j = 0; j < path.Count; j++)
{
object input = path[j];
TransducerGraph.Arc a = graph.GetArcBySourceAndInput(source, input);
if (a != null)
{
// increment the arc weight
a.output = ((double)a.output) + count;
}
else
{
object target;
if (input.Equals(TransducerGraph.EpsilonInput))
{
target = "END";
}
else
{
// to ensure they all share the same end node
if (markovOrder == 0)
{
// we all transition back to the same state
target = source;
}
else
{
if (markovOrder > 0)
{
// the state is described by the partial history
target = path.SubList((j < markovOrder ? 0 : j - markovOrder + 1), j + 1);
}
else
{
// the state is described by the full history
target = path.SubList(0, j + 1);
}
}
}
double output = count;
a = new TransducerGraph.Arc(source, target, input, output);
graph.AddArc(a);
}
source = a.GetTargetNode();
}
graph.SetEndNode(source);
}
