update TableFactor to use new version of DT probabilities

gtsam/discrete/TableFactor.cpp

@@ -56,19 +56,45 @@ TableFactor::TableFactor(const DiscreteKeys& dkeys,
   sort(sorted_dkeys_.begin(), sorted_dkeys_.end());
 }
 
-/* ************************************************************************ */
-TableFactor::TableFactor(const DiscreteKeys& dkeys,
-                         const DecisionTreeFactor& dtf)
-    : TableFactor(dkeys, dtf.probabilities()) {}
-
 /* ************************************************************************ */
 TableFactor::TableFactor(const DiscreteKeys& dkeys,
                          const DecisionTree<Key, double>& dtree)
     : TableFactor(dkeys, DecisionTreeFactor(dkeys, dtree)) {}
 
+/**
+ * @brief Compute the correct ordering of the leaves in the decision tree.
+ *
+ * This is done by first taking all the values which have modulo 0 value with
+ * the cardinality of the innermost key `n`, and we go up to modulo n.
+ *
+ * @param dt The DecisionTree
+ * @return std::vector<double>
+ */
+std::vector<double> ComputeLeafOrdering(const DiscreteKeys& dkeys,
+                                        const DecisionTreeFactor& dt) {
+  std::vector<double> probs = dt.probabilities();
+  std::vector<double> ordered;
+
+  size_t n = dkeys[0].second;
+
+  for (size_t k = 0; k < n; ++k) {
+    for (size_t idx = 0; idx < probs.size(); ++idx) {
+      if (idx % n == k) {
+        ordered.push_back(probs[idx]);
+      }
+    }
+  }
+  return ordered;
+}
+
+/* ************************************************************************ */
+TableFactor::TableFactor(const DiscreteKeys& dkeys,
+                         const DecisionTreeFactor& dtf)
+    : TableFactor(dkeys, ComputeLeafOrdering(dkeys, dtf)) {}
+
 /* ************************************************************************ */
 TableFactor::TableFactor(const DiscreteConditional& c)
-    : TableFactor(c.discreteKeys(), c.probabilities()) {}
+    : TableFactor(c.discreteKeys(), c) {}
 
 /* ************************************************************************ */
 Eigen::SparseVector<double> TableFactor::Convert(

gtsam/discrete/tests/testTableFactor.cpp

@@ -19,6 +19,7 @@
 #include <CppUnitLite/TestHarness.h>
 #include <gtsam/base/Testable.h>
 #include <gtsam/base/serializationTestHelpers.h>
+#include <gtsam/discrete/DiscreteConditional.h>
 #include <gtsam/discrete/DiscreteDistribution.h>
 #include <gtsam/discrete/Signature.h>
 #include <gtsam/discrete/TableFactor.h>
@@ -131,6 +132,16 @@ TEST(TableFactor, constructors) {
   // Manually constructed via inspection and comparison to DecisionTreeFactor
   TableFactor expected(X & Y, "0.5 0.4 0.2 0.5 0.6 0.8");
   EXPECT(assert_equal(expected, f4));
+
+  // Test for 9=3x3 values.
+  DiscreteKey V(0, 3), W(1, 3);
+  DiscreteConditional conditional5(V | W = "1/2/3 5/6/7 9/10/11");
+  TableFactor f5(conditional5);
+  // GTSAM_PRINT(f5);
+  TableFactor expected_f5(
+      X & Y,
+      "0.166667 0.277778 0.3 0.333333 0.333333 0.333333 0.5 0.388889 0.366667");
+  EXPECT(assert_equal(expected_f5, f5, 1e-6));
 }
 
 /* ************************************************************************* */