diff --git a/gtsam/discrete/DecisionTreeFactor.h b/gtsam/discrete/DecisionTreeFactor.h
index 43dd892fc..b5a037119 100644
--- a/gtsam/discrete/DecisionTreeFactor.h
+++ b/gtsam/discrete/DecisionTreeFactor.h
@@ -66,6 +66,10 @@ namespace gtsam {
     DecisionTreeFactor(const DiscreteKey& key, SOURCE table)
         : DecisionTreeFactor(DiscreteKeys{key}, table) {}
 
+    /// Single-key specialization, with vector of doubles.
+    DecisionTreeFactor(const DiscreteKey& key, const std::vector<double>& row)
+        : DecisionTreeFactor(DiscreteKeys{key}, row) {}
+
     /// Two-key specialization
     template <class SOURCE>
     DecisionTreeFactor(const DiscreteKey& key1, const DiscreteKey& key2,
diff --git a/gtsam/discrete/discrete.i b/gtsam/discrete/discrete.i
index 0f319562f..971250ba1 100644
--- a/gtsam/discrete/discrete.i
+++ b/gtsam/discrete/discrete.i
@@ -33,6 +33,8 @@ class DiscreteFactor {
 virtual class DecisionTreeFactor : gtsam::DiscreteFactor {
   DecisionTreeFactor();
   DecisionTreeFactor(const gtsam::DiscreteKeys& keys, string table);
+  DecisionTreeFactor(const gtsam::DiscreteKey& key,
+                     const std::vector<double>& spec);
   DecisionTreeFactor(const gtsam::DiscreteKey& key, const std::string& spec);
   DecisionTreeFactor(const gtsam::DiscreteKey& key1,
                      const gtsam::DiscreteKey& key2, const std::string& spec);
@@ -175,6 +177,7 @@ class DiscreteFactorGraph {
   DiscreteFactorGraph();
   DiscreteFactorGraph(const gtsam::DiscreteBayesNet& bayesNet);
   
+  void add(const gtsam::DiscreteKey& j, const std::vector<double>& spec);
   void add(const gtsam::DiscreteKey& j, string table);
   void add(const gtsam::DiscreteKey& j1, const gtsam::DiscreteKey& j2, string table);
   void add(const gtsam::DiscreteKeys& keys, string table);
diff --git a/gtsam/discrete/tests/testDecisionTreeFactor.cpp b/gtsam/discrete/tests/testDecisionTreeFactor.cpp
index ad8e9bd2a..542d16b29 100644
--- a/gtsam/discrete/tests/testDecisionTreeFactor.cpp
+++ b/gtsam/discrete/tests/testDecisionTreeFactor.cpp
@@ -34,7 +34,7 @@ TEST( DecisionTreeFactor, constructors)
   DiscreteKey X(0,2), Y(1,3), Z(2,2);
 
   // Create factors
-  DecisionTreeFactor f1(X, "2 8");
+  DecisionTreeFactor f1(X, {2, 8});
   DecisionTreeFactor f2(X & Y, "2 5 3 6 4 7");
   DecisionTreeFactor f3(X & Y & Z, "2 5 3 6 4 7 25 55 35 65 45 75");
   EXPECT_LONGS_EQUAL(1,f1.size());
diff --git a/python/gtsam/tests/test_DiscreteFactorGraph.py b/python/gtsam/tests/test_DiscreteFactorGraph.py
index 9dafff33f..dc2c7a4f5 100644
--- a/python/gtsam/tests/test_DiscreteFactorGraph.py
+++ b/python/gtsam/tests/test_DiscreteFactorGraph.py
@@ -32,7 +32,7 @@ class TestDiscreteFactorGraph(GtsamTestCase):
         graph = DiscreteFactorGraph()
 
         # Add two unary factors (priors)
-        graph.add(P1, "0.9 0.3")
+        graph.add(P1, [0.9, 0.3])
         graph.add(P2, "0.9 0.6")
 
         # Add a binary factor