From 67e1897e475c7dc2380665e1e1a422b8ec96ae3e Mon Sep 17 00:00:00 2001
From: Frank Dellaert <dellaert@gmail.com>
Date: Thu, 10 Dec 2009 20:17:11 +0000
Subject: [PATCH] Get and [] now return references, new imperative add method

---
 cpp/VectorConfig.cpp |  2 +-
 cpp/VectorConfig.h   | 10 ++++++++--
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/cpp/VectorConfig.cpp b/cpp/VectorConfig.cpp
index 4ba8fa957..8577b3561 100644
--- a/cpp/VectorConfig.cpp
+++ b/cpp/VectorConfig.cpp
@@ -55,7 +55,7 @@ VectorConfig VectorConfig::exmap(const VectorConfig & delta) const
 }
 
 /* ************************************************************************* */
-Vector VectorConfig::get(const std::string& name) const {
+const Vector& VectorConfig::get(const std::string& name) const {
   const_iterator it = values.find(name);
   if (it==values.end()) {
     print();
diff --git a/cpp/VectorConfig.h b/cpp/VectorConfig.h
index 4f7cb7d96..32449a6be 100644
--- a/cpp/VectorConfig.h
+++ b/cpp/VectorConfig.h
@@ -47,6 +47,12 @@ namespace gtsam {
       return *this;
     }
 
+    /** Add to vector at position j */
+    void add(const std::string& j, const Vector& a) {
+    	Vector& vj = values[j];
+    	if (vj.size()==0) vj = a; else vj += a;
+    }
+
     /**
      * Add a delta config, needed for use in NonlinearOptimizer
      * For VectorConfig, this is just addition.
@@ -60,10 +66,10 @@ namespace gtsam {
     const_iterator end()   const {return values.end();}
 
     /** get a vector in the configuration by name */
-    Vector get(const std::string& name) const;
+    const Vector& get(const std::string& name) const;
 
     /** operator[] syntax for get */
-    inline Vector operator[](const std::string& name) const { return get(name); }
+    inline const Vector& operator[](const std::string& name) const { return get(name); }
 
     bool contains(const std::string& name) const {
       const_iterator it = values.find(name);