From 094b76df2d4c43545353c7ec9f70d6dd4eee0f27 Mon Sep 17 00:00:00 2001
From: Varun Agrawal <varagrawal@gmail.com>
Date: Tue, 31 Dec 2024 17:06:57 -0500
Subject: [PATCH] fix bug in TableFactor when trying to convert to
 DecisionTreeFactor

---
 gtsam/discrete/TableFactor.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/gtsam/discrete/TableFactor.cpp b/gtsam/discrete/TableFactor.cpp
index bf9662e34..67ba19d39 100644
--- a/gtsam/discrete/TableFactor.cpp
+++ b/gtsam/discrete/TableFactor.cpp
@@ -252,6 +252,11 @@ DecisionTreeFactor TableFactor::operator*(const DecisionTreeFactor& f) const {
 DecisionTreeFactor TableFactor::toDecisionTreeFactor() const {
   DiscreteKeys dkeys = discreteKeys();
 
+  // If no keys, then return empty DecisionTreeFactor
+  if (dkeys.size() == 0) {
+    return DecisionTreeFactor(dkeys, AlgebraicDecisionTree<Key>());
+  }
+
   std::vector<double> table;
   for (auto i = 0; i < sparse_table_.size(); i++) {
     table.push_back(sparse_table_.coeff(i));