diff --git a/gtsam/base/Vector.cpp b/gtsam/base/Vector.cpp
index 3365525c4..c69a0ad20 100644
--- a/gtsam/base/Vector.cpp
+++ b/gtsam/base/Vector.cpp
@@ -176,11 +176,6 @@ bool linear_dependent(const Vector& vec1, const Vector& vec2, double tol) {
   return flag;
 }
 
-/* ************************************************************************* */
-ConstSubVector sub(const Vector &v, size_t i1, size_t i2) {
-  return v.segment(i1,i2-i1);
-}
-
 /* ************************************************************************* */
 Vector ediv_(const Vector &a, const Vector &b) {
   size_t n = a.size();
diff --git a/gtsam/base/Vector.h b/gtsam/base/Vector.h
index 3b0634702..d4502b6ad 100644
--- a/gtsam/base/Vector.h
+++ b/gtsam/base/Vector.h
@@ -195,15 +195,6 @@ GTSAM_EXPORT bool assert_equal(const ConstSubVector& vec1, const ConstSubVector&
  */
 GTSAM_EXPORT bool linear_dependent(const Vector& vec1, const Vector& vec2, double tol=1e-9);
 
-/**
- * extract subvector, slice semantics, i.e. range = [i1,i2[ excluding i2
- * @param v Vector
- * @param i1 first row index
- * @param i2 last  row index + 1
- * @return subvector v(i1:i2)
- */
-GTSAM_EXPORT ConstSubVector sub(const Vector &v, size_t i1, size_t i2);
-
 /**
  * elementwise division, but 0/0 = 0, not inf
  * @param a first vector
@@ -296,6 +287,7 @@ GTSAM_EXPORT inline Vector emul(const Vector &a, const Vector &b) {assert (b.siz
 GTSAM_EXPORT inline double max(const Vector &a){return a.maxCoeff();}
 GTSAM_EXPORT inline double norm_2(const Vector& v) {return v.norm();}
 GTSAM_EXPORT inline Vector reciprocal(const Vector &a) {return a.array().inverse();}
+GTSAM_EXPORT ConstSubVector sub(const Vector &v, size_t i1, size_t i2) {return v.segment(i1,i2-i1);}
 GTSAM_EXPORT void subInsert(Vector& fullVector, const Vector& subVector, size_t i) {fullVector.segment(i, subVector.size()) = subVector;}
 GTSAM_EXPORT inline double sum(const Vector &a){return a.sum();}
 #endif
diff --git a/gtsam/base/tests/testVector.cpp b/gtsam/base/tests/testVector.cpp
index 7e421573b..7e794ac04 100644
--- a/gtsam/base/tests/testVector.cpp
+++ b/gtsam/base/tests/testVector.cpp
@@ -126,7 +126,7 @@ TEST(Vector, sub )
   a(0) = 10; a(1) = 20; a(2) = 3;
   a(3) = 34; a(4) = 11; a(5) = 2;
 
-  Vector result(sub(a,2,5));
+  Vector result(a.segment(2,3));
 
   Vector b(3);
   b(0) = 3; b(1) = 34; b(2) =11;
diff --git a/gtsam/linear/VectorValues.cpp b/gtsam/linear/VectorValues.cpp
index 33c62cfb6..1439d4b61 100644
--- a/gtsam/linear/VectorValues.cpp
+++ b/gtsam/linear/VectorValues.cpp
@@ -52,7 +52,7 @@ namespace gtsam {
       Key key;
       size_t n;
       boost::tie(key, n) = v;
-      values_.insert(make_pair(key, sub(x, j, j + n)));
+      values_.insert(make_pair(key, x.segment(j,n)));
       j += n;
     }
   }
diff --git a/gtsam_unstable/slam/Mechanization_bRn2.cpp b/gtsam_unstable/slam/Mechanization_bRn2.cpp
index 2205f53bd..edd92b580 100644
--- a/gtsam_unstable/slam/Mechanization_bRn2.cpp
+++ b/gtsam_unstable/slam/Mechanization_bRn2.cpp
@@ -67,13 +67,13 @@ Mechanization_bRn2 Mechanization_bRn2::initialize(const Matrix& U,
 
 /* ************************************************************************* */
 Mechanization_bRn2 Mechanization_bRn2::correct(const Vector3& dx) const {
-  Vector3 rho = sub(dx, 0, 3);
+  Vector3 rho = dx.segment(0,3);
 
   Rot3 delta_nRn = Rot3::Rodrigues(rho);
   Rot3 bRn = bRn_ * delta_nRn;
 
-  Vector3 x_g = x_g_ + sub(dx, 3, 6);
-  Vector3 x_a = x_a_ + sub(dx, 6, 9);
+  Vector3 x_g = x_g_ + dx.segment(3,3);
+  Vector3 x_a = x_a_ + dx.segment(6,3);
 
   return Mechanization_bRn2(bRn, x_g, x_a);
 }