From 1a862c24a699487a627ffa790a4e246b7a3066bf Mon Sep 17 00:00:00 2001
From: Frank Dellaert <dellaert@gmail.com>
Date: Mon, 8 Apr 2019 16:51:39 -0400
Subject: [PATCH] Reserve memory for cache

---
 gtsam/linear/SubgraphPreconditioner.cpp | 1 +
 1 file changed, 1 insertion(+)

diff --git a/gtsam/linear/SubgraphPreconditioner.cpp b/gtsam/linear/SubgraphPreconditioner.cpp
index 657846f95..9578d45bd 100644
--- a/gtsam/linear/SubgraphPreconditioner.cpp
+++ b/gtsam/linear/SubgraphPreconditioner.cpp
@@ -658,6 +658,7 @@ Vector getSubvector(const Vector &src, const KeyInfo &keyInfo,
                     const KeyVector &keys) {
   /* a cache of starting index and dim */
   vector<std::pair<size_t, size_t> > cache;
+  cache.reserve(3);
 
   /* figure out dimension by traversing the keys */
   size_t dim = 0;