Hybrid Elimination with Normalization Constant

gtsam/discrete/DecisionTree-inl.h

@@ -64,6 +64,9 @@ namespace gtsam {
      */
     size_t nrAssignments_;
 
+    /// Default constructor for serialization.
+    Leaf() {}
+
     /// Constructor from constant
     Leaf(const Y& constant, size_t nrAssignments = 1)
         : constant_(constant), nrAssignments_(nrAssignments) {}
@@ -154,6 +157,18 @@ namespace gtsam {
     }
 
     bool isLeaf() const override { return true; }
+
+   private:
+    using Base = DecisionTree<L, Y>::Node;
+
+    /** Serialization function */
+    friend class boost::serialization::access;
+    template <class ARCHIVE>
+    void serialize(ARCHIVE& ar, const unsigned int /*version*/) {
+      ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(Base);
+      ar& BOOST_SERIALIZATION_NVP(constant_);
+      ar& BOOST_SERIALIZATION_NVP(nrAssignments_);
+    }
   };  // Leaf
 
   /****************************************************************************/
@@ -177,6 +192,9 @@ namespace gtsam {
     using ChoicePtr = boost::shared_ptr<const Choice>;
 
    public:
+    /// Default constructor for serialization.
+    Choice() {}
+
     ~Choice() override {
 #ifdef DT_DEBUG_MEMORY
       std::std::cout << Node::nrNodes << " destructing (Choice) " << this->id()
@@ -428,6 +446,19 @@ namespace gtsam {
         r->push_back(branch->choose(label, index));
       return Unique(r);
     }
+
+   private:
+    using Base = DecisionTree<L, Y>::Node;
+
+    /** Serialization function */
+    friend class boost::serialization::access;
+    template <class ARCHIVE>
+    void serialize(ARCHIVE& ar, const unsigned int /*version*/) {
+      ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(Base);
+      ar& BOOST_SERIALIZATION_NVP(label_);
+      ar& BOOST_SERIALIZATION_NVP(branches_);
+      ar& BOOST_SERIALIZATION_NVP(allSame_);
+    }
   };  // Choice
 
   /****************************************************************************/

gtsam/discrete/DecisionTree.h

@@ -19,9 +19,11 @@
 
 #pragma once
 
+#include <gtsam/base/Testable.h>
 #include <gtsam/base/types.h>
 #include <gtsam/discrete/Assignment.h>
 
+#include <boost/serialization/nvp.hpp>
 #include <boost/shared_ptr.hpp>
 #include <functional>
 #include <iostream>
@@ -113,6 +115,12 @@ namespace gtsam {
       virtual Ptr apply_g_op_fC(const Choice&, const Binary&) const = 0;
       virtual Ptr choose(const L& label, size_t index) const = 0;
       virtual bool isLeaf() const = 0;
+
+     private:
+      /** Serialization function */
+      friend class boost::serialization::access;
+      template <class ARCHIVE>
+      void serialize(ARCHIVE& ar, const unsigned int /*version*/) {}
     };
     /** ------------------------ Node base class --------------------------- */
 
@@ -236,7 +244,7 @@ namespace gtsam {
     /**
      * @brief Visit all leaves in depth-first fashion.
      *
-     * @param f (side-effect) Function taking a value.
+     * @param f (side-effect) Function taking the value of the leaf node.
      *
      * @note Due to pruning, the number of leaves may not be the same as the
      * number of assignments. E.g. if we have a tree on 2 binary variables with
@@ -245,7 +253,7 @@ namespace gtsam {
      * Example:
      *   int sum = 0;
      *   auto visitor = [&](int y) { sum += y; };
-     *   tree.visitWith(visitor);
+     *   tree.visit(visitor);
      */
     template <typename Func>
     void visit(Func f) const;
@@ -261,8 +269,8 @@ namespace gtsam {
      *
      * Example:
      *   int sum = 0;
-     *   auto visitor = [&](int y) { sum += y; };
-     *   tree.visitWith(visitor);
+     *   auto visitor = [&](const Leaf& leaf) { sum += leaf.constant(); };
+     *   tree.visitLeaf(visitor);
      */
     template <typename Func>
     void visitLeaf(Func f) const;
@@ -364,8 +372,19 @@ namespace gtsam {
     compose(Iterator begin, Iterator end, const L& label) const;
 
     /// @}
+
+   private:
+    /** Serialization function */
+    friend class boost::serialization::access;
+    template <class ARCHIVE>
+    void serialize(ARCHIVE& ar, const unsigned int /*version*/) {
+      ar& BOOST_SERIALIZATION_NVP(root_);
+    }
   };  // DecisionTree
 
+  template <class L, class Y>
+  struct traits<DecisionTree<L, Y>> : public Testable<DecisionTree<L, Y>> {};
+
   /** free versions of apply */
 
   /// Apply unary operator `op` to DecisionTree `f`.

gtsam/discrete/DecisionTreeFactor.h

@@ -231,6 +231,16 @@ namespace gtsam {
                     const Names& names = {}) const override;
 
     /// @}
+
+   private:
+    /** Serialization function */
+    friend class boost::serialization::access;
+    template <class ARCHIVE>
+    void serialize(ARCHIVE& ar, const unsigned int /*version*/) {
+      ar& BOOST_SERIALIZATION_BASE_OBJECT_NVP(Base);
+      ar& BOOST_SERIALIZATION_BASE_OBJECT_NVP(ADT);
+      ar& BOOST_SERIALIZATION_NVP(cardinalities_);
+    }
   };
 
 // traits

gtsam/discrete/DiscreteConditional.h

@@ -239,6 +239,15 @@ class GTSAM_EXPORT DiscreteConditional
   /// Internal version of choose
   DiscreteConditional::ADT choose(const DiscreteValues& given,
                                   bool forceComplete) const;
+
+ private:
+  /** Serialization function */
+  friend class boost::serialization::access;
+  template <class Archive>
+  void serialize(Archive& ar, const unsigned int /*version*/) {
+    ar& BOOST_SERIALIZATION_BASE_OBJECT_NVP(BaseFactor);
+    ar& BOOST_SERIALIZATION_BASE_OBJECT_NVP(BaseConditional);
+  }
 };
 // DiscreteConditional
 

gtsam/discrete/tests/testDecisionTree.cpp

@@ -20,13 +20,12 @@
 // #define DT_DEBUG_MEMORY
 // #define GTSAM_DT_NO_PRUNING
 #define DISABLE_DOT
-#include <gtsam/discrete/DecisionTree-inl.h>
-
+#include <CppUnitLite/TestHarness.h>
 #include <gtsam/base/Testable.h>
+#include <gtsam/base/serializationTestHelpers.h>
+#include <gtsam/discrete/DecisionTree-inl.h>
 #include <gtsam/discrete/Signature.h>
 
-#include <CppUnitLite/TestHarness.h>
-
 using namespace std;
 using namespace gtsam;
 

gtsam/discrete/tests/testDecisionTreeFactor.cpp

@@ -19,6 +19,7 @@
 
 #include <CppUnitLite/TestHarness.h>
 #include <gtsam/base/Testable.h>
+#include <gtsam/base/serializationTestHelpers.h>
 #include <gtsam/discrete/DecisionTreeFactor.h>
 #include <gtsam/discrete/DiscreteDistribution.h>
 #include <gtsam/discrete/Signature.h>

gtsam/discrete/tests/testDiscreteConditional.cpp

@@ -17,13 +17,14 @@
  * @date    Feb 14, 2011
  */
 
-#include <boost/make_shared.hpp>
-
 #include <CppUnitLite/TestHarness.h>
+#include <gtsam/base/serializationTestHelpers.h>
 #include <gtsam/discrete/DecisionTreeFactor.h>
 #include <gtsam/discrete/DiscreteConditional.h>
 #include <gtsam/inference/Symbol.h>
 
+#include <boost/make_shared.hpp>
+
 using namespace std;
 using namespace gtsam;
 
@@ -209,7 +210,6 @@ TEST(DiscreteConditional, marginals2) {
   DiscreteConditional conditional(A | B = "2/2 3/1");
   DiscreteConditional prior(B % "1/2");
   DiscreteConditional pAB = prior * conditional;
-  GTSAM_PRINT(pAB);
   // P(A=0) = P(A=0|B=0)P(B=0) + P(A=0|B=1)P(B=1) = 2*1 + 3*2 = 8
   // P(A=1) = P(A=1|B=0)P(B=0) + P(A=1|B=1)P(B=1) = 2*1 + 1*2 = 4
   DiscreteConditional actualA = pAB.marginal(A.first);

gtsam/discrete/tests/testSerializationDiscrete.cpp

@@ -0,0 +1,105 @@
+/* ----------------------------------------------------------------------------
+
+ * GTSAM Copyright 2010, Georgia Tech Research Corporation,
+ * Atlanta, Georgia 30332-0415
+ * All Rights Reserved
+ * Authors: Frank Dellaert, et al. (see THANKS for the full author list)
+
+ * See LICENSE for the license information
+
+ * -------------------------------------------------------------------------- */
+
+/*
+ * testSerializtionDiscrete.cpp
+ *
+ *  @date January 2023
+ *  @author Varun Agrawal
+ */
+
+#include <CppUnitLite/TestHarness.h>
+#include <gtsam/base/serializationTestHelpers.h>
+#include <gtsam/discrete/DecisionTreeFactor.h>
+#include <gtsam/discrete/DiscreteDistribution.h>
+#include <gtsam/inference/Symbol.h>
+
+using namespace std;
+using namespace gtsam;
+
+using Tree = gtsam::DecisionTree<string, int>;
+
+BOOST_CLASS_EXPORT_GUID(Tree, "gtsam_DecisionTreeStringInt")
+BOOST_CLASS_EXPORT_GUID(Tree::Leaf, "gtsam_DecisionTreeStringInt_Leaf")
+BOOST_CLASS_EXPORT_GUID(Tree::Choice, "gtsam_DecisionTreeStringInt_Choice")
+
+BOOST_CLASS_EXPORT_GUID(DecisionTreeFactor, "gtsam_DecisionTreeFactor");
+
+using ADT = AlgebraicDecisionTree<Key>;
+BOOST_CLASS_EXPORT_GUID(ADT, "gtsam_AlgebraicDecisionTree");
+BOOST_CLASS_EXPORT_GUID(ADT::Leaf, "gtsam_AlgebraicDecisionTree_Leaf")
+BOOST_CLASS_EXPORT_GUID(ADT::Choice, "gtsam_AlgebraicDecisionTree_Choice")
+
+/* ****************************************************************************/
+// Test DecisionTree serialization.
+TEST(DiscreteSerialization, DecisionTree) {
+  Tree tree({{"A", 2}}, std::vector<int>{1, 2});
+
+  using namespace serializationTestHelpers;
+
+  // Object roundtrip
+  Tree outputObj = create<Tree>();
+  roundtrip<Tree>(tree, outputObj);
+  EXPECT(tree.equals(outputObj));
+
+  // XML roundtrip
+  Tree outputXml = create<Tree>();
+  roundtripXML<Tree>(tree, outputXml);
+  EXPECT(tree.equals(outputXml));
+
+  // Binary roundtrip
+  Tree outputBinary = create<Tree>();
+  roundtripBinary<Tree>(tree, outputBinary);
+  EXPECT(tree.equals(outputBinary));
+}
+
+/* ************************************************************************* */
+// Check serialization for AlgebraicDecisionTree and the DecisionTreeFactor
+TEST(DiscreteSerialization, DecisionTreeFactor) {
+  using namespace serializationTestHelpers;
+
+  DiscreteKey A(1, 2), B(2, 2), C(3, 2);
+
+  DecisionTreeFactor::ADT tree(A & B & C, "1 5 3 7 2 6 4 8");
+  EXPECT(equalsObj<DecisionTreeFactor::ADT>(tree));
+  EXPECT(equalsXML<DecisionTreeFactor::ADT>(tree));
+  EXPECT(equalsBinary<DecisionTreeFactor::ADT>(tree));
+
+  DecisionTreeFactor f(A & B & C, "1 5 3 7 2 6 4 8");
+  EXPECT(equalsObj<DecisionTreeFactor>(f));
+  EXPECT(equalsXML<DecisionTreeFactor>(f));
+  EXPECT(equalsBinary<DecisionTreeFactor>(f));
+}
+
+/* ************************************************************************* */
+// Check serialization for DiscreteConditional & DiscreteDistribution
+TEST(DiscreteSerialization, DiscreteConditional) {
+  using namespace serializationTestHelpers;
+
+  DiscreteKey A(Symbol('x', 1), 3);
+  DiscreteConditional conditional(A % "1/2/2");
+
+  EXPECT(equalsObj<DiscreteConditional>(conditional));
+  EXPECT(equalsXML<DiscreteConditional>(conditional));
+  EXPECT(equalsBinary<DiscreteConditional>(conditional));
+
+  DiscreteDistribution P(A % "3/2/1");
+  EXPECT(equalsObj<DiscreteDistribution>(P));
+  EXPECT(equalsXML<DiscreteDistribution>(P));
+  EXPECT(equalsBinary<DiscreteDistribution>(P));
+}
+
+/* ************************************************************************* */
+int main() {
+  TestResult tr;
+  return TestRegistry::runAllTests(tr);
+}
+/* ************************************************************************* */

gtsam/hybrid/GaussianMixture.cpp

@@ -51,24 +51,29 @@ GaussianMixture::GaussianMixture(
                       Conditionals(discreteParents, conditionalsList)) {}
 
 /* *******************************************************************************/
-GaussianMixture::Sum GaussianMixture::add(
-    const GaussianMixture::Sum &sum) const {
-  using Y = GaussianFactorGraph;
+GaussianFactorGraphTree GaussianMixture::add(
+    const GaussianFactorGraphTree &sum) const {
+  using Y = GraphAndConstant;
   auto add = [](const Y &graph1, const Y &graph2) {
-    auto result = graph1;
-    result.push_back(graph2);
-    return result;
+    auto result = graph1.graph;
+    result.push_back(graph2.graph);
+    return Y(result, graph1.constant + graph2.constant);
   };
-  const Sum tree = asGaussianFactorGraphTree();
+  const auto tree = asGaussianFactorGraphTree();
   return sum.empty() ? tree : sum.apply(tree, add);
 }
 
 /* *******************************************************************************/
-GaussianMixture::Sum GaussianMixture::asGaussianFactorGraphTree() const {
-  auto lambda = [](const GaussianFactor::shared_ptr &factor) {
+GaussianFactorGraphTree GaussianMixture::asGaussianFactorGraphTree() const {
+  auto lambda = [](const GaussianConditional::shared_ptr &conditional) {
     GaussianFactorGraph result;
-    result.push_back(factor);
-    return result;
+    result.push_back(conditional);
+    if (conditional) {
+      return GraphAndConstant(
+          result, conditional->logNormalizationConstant());
+    } else {
+      return GraphAndConstant(result, 0.0);
+    }
   };
   return {conditionals_, lambda};
 }
@@ -98,7 +103,19 @@ GaussianConditional::shared_ptr GaussianMixture::operator()(
 /* *******************************************************************************/
 bool GaussianMixture::equals(const HybridFactor &lf, double tol) const {
   const This *e = dynamic_cast<const This *>(&lf);
-  return e != nullptr && BaseFactor::equals(*e, tol);
+  if (e == nullptr) return false;
+
+  // This will return false if either conditionals_ is empty or e->conditionals_
+  // is empty, but not if both are empty or both are not empty:
+  if (conditionals_.empty() ^ e->conditionals_.empty()) return false;
+
+  // Check the base and the factors:
+  return BaseFactor::equals(*e, tol) &&
+         conditionals_.equals(e->conditionals_,
+                              [tol](const GaussianConditional::shared_ptr &f1,
+                                    const GaussianConditional::shared_ptr &f2) {
+                                return f1->equals(*(f2), tol);
+                              });
 }
 
 /* *******************************************************************************/