diff --git a/gtsam.h b/gtsam.h
index c0e90f4a7..7eb0a27b3 100644
--- a/gtsam.h
+++ b/gtsam.h
@@ -28,10 +28,10 @@ class Rot2 {
 
 class Pose2 {
 	Pose2();
-	Pose2(const Pose2& pose);
 	Pose2(double x, double y, double theta);
 	Pose2(double theta, const Point2& t);
 	Pose2(const Rot2& r, const Point2& t);
+	Pose2(Vector v);
 	void print(string s) const;
 	bool equals(const Pose2& pose, double tol) const;
 	double x() const;
@@ -40,11 +40,11 @@ class Pose2 {
 	int dim() const;
 	Pose2* compose_(const Pose2& p2);
 	Pose2* between_(const Pose2& p2);
+	Vector logmap(const Pose2& p);
 };
 
 class SharedGaussian {
 	SharedGaussian(Matrix covariance);
-	SharedGaussian(Vector sigmas);
 };
 
 class SharedDiagonal {
diff --git a/gtsam/geometry/Pose2.h b/gtsam/geometry/Pose2.h
index e45b9d72f..e1d40265a 100644
--- a/gtsam/geometry/Pose2.h
+++ b/gtsam/geometry/Pose2.h
@@ -70,7 +70,16 @@ namespace gtsam {
 
     /** Constructor from 3*3 matrix */
     Pose2(const Matrix &T) :
-      r_(Rot2::atan2(T(1, 0), T(0, 0))), t_(T(0, 2), T(1, 2)) { assert(T.rows()==3 && T.cols()==3); }
+				r_(Rot2::atan2(T(1, 0), T(0, 0))), t_(T(0, 2), T(1, 2)) {
+			assert(T.rows() == 3 && T.cols() == 3);
+		}
+
+    /** Construct from canonical coordinates (Lie algebra) */
+    Pose2(const Vector& v) {
+    	Pose2 pose = Expmap(v);
+    	r_ = pose.r_;
+    	t_ = pose.t_;
+    }
 
     /** print with optional string */
     void print(const std::string& s = "") const;
diff --git a/gtsam/geometry/tests/testPose2.cpp b/gtsam/geometry/tests/testPose2.cpp
index 95603fce1..104d47e31 100644
--- a/gtsam/geometry/tests/testPose2.cpp
+++ b/gtsam/geometry/tests/testPose2.cpp
@@ -103,7 +103,10 @@ TEST(Pose2, expmap2) {
   Matrix A2 = A*A/2.0, A3 = A2*A/3.0, A4=A3*A/4.0;
   Matrix expected = eye(3) + A + A2 + A3 + A4;
 
-  Pose2 pose = Pose2::Expmap(Vector_(3, 0.01, -0.015, 0.99));
+  Vector v = Vector_(3, 0.01, -0.015, 0.99);
+  Pose2 pose = Pose2::Expmap(v);
+  Pose2 pose2(v);
+  EXPECT(assert_equal(pose, pose2));
   Matrix actual = pose.matrix();
   //EXPECT(assert_equal(expected, actual));
 }