From 428cde23793618003c709e645ae6f0d23e558d1a Mon Sep 17 00:00:00 2001
From: dellaert <dellaert@cc.gatech.edu>
Date: Fri, 28 Nov 2014 12:31:40 +0100
Subject: [PATCH] Added two coomnly used constants

---
 gtsam/base/Matrix.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/gtsam/base/Matrix.h b/gtsam/base/Matrix.h
index 132bf79ad..9c273f78c 100644
--- a/gtsam/base/Matrix.h
+++ b/gtsam/base/Matrix.h
@@ -63,6 +63,10 @@ typedef Eigen::Matrix<double,3,9> Matrix39;
 typedef Eigen::Block<Matrix> SubMatrix;
 typedef Eigen::Block<const Matrix> ConstSubMatrix;
 
+// Two very commonly used matrices:
+const Matrix3 Z_3x3 = Matrix3::Zero();
+const Matrix3 I_3x3 = Matrix3::Identity();
+
 // Matlab-like syntax
 
 /**