From f8468bd59624906e4982c11c253b4f365f1ae395 Mon Sep 17 00:00:00 2001
From: dellaert <dellaert@cc.gatech.edu>
Date: Fri, 10 Oct 2014 12:31:40 +0200
Subject: [PATCH] Recursion done

---
 gtsam_unstable/nonlinear/Expression-inl.h               | 9 ++++++---
 gtsam_unstable/nonlinear/tests/testExpressionFactor.cpp | 3 +++
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/gtsam_unstable/nonlinear/Expression-inl.h b/gtsam_unstable/nonlinear/Expression-inl.h
index 53f531149..8b98b3b94 100644
--- a/gtsam_unstable/nonlinear/Expression-inl.h
+++ b/gtsam_unstable/nonlinear/Expression-inl.h
@@ -120,10 +120,13 @@ struct JacobianTrace {
   /// Make sure destructor is virtual
   virtual ~JacobianTrace() {
   }
-  virtual void startReverseAD(JacobianMap& jacobians) const = 0;
-  virtual void reverseAD(const Matrix& dFdT, JacobianMap& jacobians) const = 0;
+  virtual void startReverseAD(JacobianMap& jacobians) const {
+  }
+  virtual void reverseAD(const Matrix& dFdT, JacobianMap& jacobians) const {
+  }
   virtual void reverseAD2(const Jacobian2T& dFdT,
-      JacobianMap& jacobians) const = 0;
+      JacobianMap& jacobians) const {
+  }
 };
 
 /// Primary template calls the generic Matrix reverseAD pipeline
diff --git a/gtsam_unstable/nonlinear/tests/testExpressionFactor.cpp b/gtsam_unstable/nonlinear/tests/testExpressionFactor.cpp
index d3f80d2a6..e5e5e41e6 100644
--- a/gtsam_unstable/nonlinear/tests/testExpressionFactor.cpp
+++ b/gtsam_unstable/nonlinear/tests/testExpressionFactor.cpp
@@ -339,15 +339,18 @@ struct Trace: More {
 
   /// Start the reverse AD process
   virtual void startReverseAD(JacobianMap& jacobians) const {
+    More::startReverseAD(jacobians);
     Select<T::dimension, A>::reverseAD(trace, dTdA, jacobians);
   }
   /// Given df/dT, multiply in dT/dA and continue reverse AD process
   virtual void reverseAD(const Matrix& dFdT, JacobianMap& jacobians) const {
+    More::reverseAD(dFdT, jacobians);
     trace.reverseAD(dFdT * dTdA, jacobians);
   }
   /// Version specialized to 2-dimensional output
   virtual void reverseAD2(const Jacobian2T& dFdT,
       JacobianMap& jacobians) const {
+    More::reverseAD2(dFdT, jacobians);
     trace.reverseAD2(dFdT * dTdA, jacobians);
   }
 };