Exemplo n.º 1
0
		public virtual void TestSumOut(TableFactor factor, int marginalize)
		{
			if (!Arrays.Stream(factor.neighborIndices).Boxed().Collect(Collectors.ToSet()).Contains(marginalize))
			{
				return;
			}
			if (factor.neighborIndices.Length <= 1)
			{
				return;
			}
			TableFactor summedOut = factor.SumOut((int)marginalize);
			NUnit.Framework.Assert.AreEqual(factor.neighborIndices.Length - 1, summedOut.neighborIndices.Length);
			NUnit.Framework.Assert.IsTrue(!Arrays.Stream(summedOut.neighborIndices).Boxed().Collect(Collectors.ToSet()).Contains(marginalize));
			IDictionary<IList<int>, IList<int[]>> subsetToSuperset = SubsetToSupersetAssignments((TableFactor)factor, summedOut);
			foreach (IList<int> subsetAssignmentList in subsetToSuperset.Keys)
			{
				double sum = 0.0;
				foreach (int[] supersetAssignment in subsetToSuperset[subsetAssignmentList])
				{
					sum += factor.GetAssignmentValue(supersetAssignment);
				}
				int[] subsetAssignment = new int[subsetAssignmentList.Count];
				for (int i = 0; i < subsetAssignment.Length; i++)
				{
					subsetAssignment[i] = subsetAssignmentList[i];
				}
				NUnit.Framework.Assert.AreEqual(summedOut.GetAssignmentValue(subsetAssignment), 1.0e-5, sum);
			}
		}
Exemplo n.º 2
0
        /// <summary>This is a key step in message passing.</summary>
        /// <remarks>
        /// This is a key step in message passing. When we are calculating a message, we want to marginalize out all variables
        /// not relevant to the recipient of the message. This function does that.
        /// </remarks>
        /// <param name="message">the message to marginalize</param>
        /// <param name="relevant">the variables that are relevant</param>
        /// <param name="marginalize">whether to use sum of max marginalization, for marginal or MAP inference</param>
        /// <returns>the marginalized message</returns>
        private static TableFactor MarginalizeMessage(TableFactor message, int[] relevant, CliqueTree.MarginalizationMethod marginalize)
        {
            TableFactor result = message;

            foreach (int i in message.neighborIndices)
            {
                bool contains = false;
                foreach (int j in relevant)
                {
                    if (i == j)
                    {
                        contains = true;
                        break;
                    }
                }
                if (!contains)
                {
                    switch (marginalize)
                    {
                    case CliqueTree.MarginalizationMethod.Sum:
                    {
                        result = result.SumOut(i);
                        break;
                    }

                    case CliqueTree.MarginalizationMethod.Max:
                    {
                        result = result.MaxOut(i);
                        break;
                    }
                    }
                }
            }
            return(result);
        }
        private void CheckMarginalsAgainstBruteForce(GraphicalModel model, ConcatVector weights, CliqueTree inference)
        {
            CliqueTree.MarginalResult result       = inference.CalculateMarginals();
            double[][] marginals                   = result.marginals;
            ICollection <TableFactor> tableFactors = model.factors.Stream().Map(null).Collect(Collectors.ToSet());

            System.Diagnostics.Debug.Assert((tableFactors.Count == model.factors.Count));
            // this is the super slow but obviously correct way to get global marginals
            TableFactor bruteForce = null;

            foreach (TableFactor factor in tableFactors)
            {
                if (bruteForce == null)
                {
                    bruteForce = factor;
                }
                else
                {
                    bruteForce = bruteForce.Multiply(factor);
                }
            }
            if (bruteForce != null)
            {
                // observe out all variables that have been registered
                TableFactor observed = bruteForce;
                for (int i = 0; i < bruteForce.neighborIndices.Length; i++)
                {
                    int n = bruteForce.neighborIndices[i];
                    if (model.GetVariableMetaDataByReference(n).Contains(CliqueTree.VariableObservedValue))
                    {
                        int value = System.Convert.ToInt32(model.GetVariableMetaDataByReference(n)[CliqueTree.VariableObservedValue]);
                        // Check that the marginals reflect the observation
                        for (int j = 0; j < marginals[n].Length; j++)
                        {
                            NUnit.Framework.Assert.AreEqual(marginals[n][j], 1.0e-9, j == value ? 1.0 : 0.0);
                        }
                        if (observed.neighborIndices.Length > 1)
                        {
                            observed = observed.Observe(n, value);
                        }
                        else
                        {
                            // If we've observed everything, then just quit
                            return;
                        }
                    }
                }
                bruteForce = observed;
                // Spot check each of the marginals in the brute force calculation
                double[][] bruteMarginals = bruteForce.GetSummedMarginals();
                int        index          = 0;
                foreach (int i_1 in bruteForce.neighborIndices)
                {
                    bool     isEqual = true;
                    double[] brute   = bruteMarginals[index];
                    index++;
                    System.Diagnostics.Debug.Assert((brute != null));
                    System.Diagnostics.Debug.Assert((marginals[i_1] != null));
                    for (int j = 0; j < brute.Length; j++)
                    {
                        if (double.IsNaN(brute[j]))
                        {
                            isEqual = false;
                            break;
                        }
                        if (Math.Abs(brute[j] - marginals[i_1][j]) > 3.0e-2)
                        {
                            isEqual = false;
                            break;
                        }
                    }
                    if (!isEqual)
                    {
                        System.Console.Error.WriteLine("Arrays not equal! Variable " + i_1);
                        System.Console.Error.WriteLine("\tGold: " + Arrays.ToString(brute));
                        System.Console.Error.WriteLine("\tResult: " + Arrays.ToString(marginals[i_1]));
                    }
                    Assert.AssertArrayEquals(marginals[i_1], 3.0e-2, brute);
                }
                // Spot check the partition function
                double goldPartitionFunction = bruteForce.ValueSum();
                // Correct to within 3%
                NUnit.Framework.Assert.AreEqual(result.partitionFunction, goldPartitionFunction * 3.0e-2, goldPartitionFunction);
                // Check the joint marginals
                foreach (GraphicalModel.Factor f in model.factors)
                {
                    NUnit.Framework.Assert.IsTrue(result.jointMarginals.Contains(f));
                    TableFactor bruteForceJointMarginal = bruteForce;
                    foreach (int n in bruteForce.neighborIndices)
                    {
                        foreach (int i_2 in f.neigborIndices)
                        {
                            if (i_2 == n)
                            {
                                goto outer_continue;
                            }
                        }
                        if (bruteForceJointMarginal.neighborIndices.Length > 1)
                        {
                            bruteForceJointMarginal = bruteForceJointMarginal.SumOut(n);
                        }
                        else
                        {
                            int[] fixedAssignment = new int[f.neigborIndices.Length];
                            for (int i_3 = 0; i_3 < fixedAssignment.Length; i_3++)
                            {
                                fixedAssignment[i_3] = System.Convert.ToInt32(model.GetVariableMetaDataByReference(f.neigborIndices[i_3])[CliqueTree.VariableObservedValue]);
                            }
                            foreach (int[] assn in result.jointMarginals[f])
                            {
                                if (Arrays.Equals(assn, fixedAssignment))
                                {
                                    NUnit.Framework.Assert.AreEqual(result.jointMarginals[f].GetAssignmentValue(assn), 1.0e-7, 1.0);
                                }
                                else
                                {
                                    if (result.jointMarginals[f].GetAssignmentValue(assn) != 0)
                                    {
                                        TableFactor j = result.jointMarginals[f];
                                        foreach (int[] assignment in j)
                                        {
                                            System.Console.Error.WriteLine(Arrays.ToString(assignment) + ": " + j.GetAssignmentValue(assignment));
                                        }
                                    }
                                    NUnit.Framework.Assert.AreEqual(result.jointMarginals[f].GetAssignmentValue(assn), 1.0e-7, 0.0);
                                }
                            }
                            goto marginals_continue;
                        }
                    }
                    outer_break :;
                    // Find the correspondence between the brute force joint marginal, which may be missing variables
                    // because they were observed out of the table, and the output joint marginals, which are always an exact
                    // match for the original factor
                    int[] backPointers  = new int[f.neigborIndices.Length];
                    int[] observedValue = new int[f.neigborIndices.Length];
                    for (int i_4 = 0; i_4 < backPointers.Length; i_4++)
                    {
                        if (model.GetVariableMetaDataByReference(f.neigborIndices[i_4]).Contains(CliqueTree.VariableObservedValue))
                        {
                            observedValue[i_4] = System.Convert.ToInt32(model.GetVariableMetaDataByReference(f.neigborIndices[i_4])[CliqueTree.VariableObservedValue]);
                            backPointers[i_4]  = -1;
                        }
                        else
                        {
                            observedValue[i_4] = -1;
                            backPointers[i_4]  = -1;
                            for (int j = 0; j < bruteForceJointMarginal.neighborIndices.Length; j++)
                            {
                                if (bruteForceJointMarginal.neighborIndices[j] == f.neigborIndices[i_4])
                                {
                                    backPointers[i_4] = j;
                                }
                            }
                            System.Diagnostics.Debug.Assert((backPointers[i_4] != -1));
                        }
                    }
                    double sum = bruteForceJointMarginal.ValueSum();
                    if (sum == 0.0)
                    {
                        sum = 1;
                    }
                    foreach (int[] assignment_1 in result.jointMarginals[f])
                    {
                        int[] bruteForceMarginalAssignment = new int[bruteForceJointMarginal.neighborIndices.Length];
                        for (int i_2 = 0; i_2 < assignment_1.Length; i_2++)
                        {
                            if (backPointers[i_2] != -1)
                            {
                                bruteForceMarginalAssignment[backPointers[i_2]] = assignment_1[i_2];
                            }
                            else
                            {
                                // Make sure all assignments that don't square with observations get 0 weight
                                System.Diagnostics.Debug.Assert((observedValue[i_2] != -1));
                                if (assignment_1[i_2] != observedValue[i_2])
                                {
                                    if (result.jointMarginals[f].GetAssignmentValue(assignment_1) != 0)
                                    {
                                        System.Console.Error.WriteLine("Joint marginals: " + Arrays.ToString(result.jointMarginals[f].neighborIndices));
                                        System.Console.Error.WriteLine("Assignment: " + Arrays.ToString(assignment_1));
                                        System.Console.Error.WriteLine("Observed Value: " + Arrays.ToString(observedValue));
                                        foreach (int[] assn in result.jointMarginals[f])
                                        {
                                            System.Console.Error.WriteLine("\t" + Arrays.ToString(assn) + ":" + result.jointMarginals[f].GetAssignmentValue(assn));
                                        }
                                    }
                                    NUnit.Framework.Assert.AreEqual(result.jointMarginals[f].GetAssignmentValue(assignment_1), 1.0e-7, 0.0);
                                    goto outer_continue;
                                }
                            }
                        }
                        NUnit.Framework.Assert.AreEqual(result.jointMarginals[f].GetAssignmentValue(assignment_1), 1.0e-3, bruteForceJointMarginal.GetAssignmentValue(bruteForceMarginalAssignment) / sum);
                    }
                    outer_break :;
                }
                marginals_break :;
            }
            else
            {
                foreach (double[] marginal in marginals)
                {
                    foreach (double d in marginal)
                    {
                        NUnit.Framework.Assert.AreEqual(d, 3.0e-2, 1.0 / marginal.Length);
                    }
                }
            }
        }