From bb4ad176da2da83034aed3263f8bba61c46e68ac Mon Sep 17 00:00:00 2001
From: Richard Roberts <richard.jw.roberts@gmail.com>
Date: Fri, 9 Aug 2013 18:50:15 +0000
Subject: [PATCH] Needed std::

---
 gtsam_unstable/slam/SmartProjectionFactor.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/gtsam_unstable/slam/SmartProjectionFactor.h b/gtsam_unstable/slam/SmartProjectionFactor.h
index f043c6873..4f3337e19 100644
--- a/gtsam_unstable/slam/SmartProjectionFactor.h
+++ b/gtsam_unstable/slam/SmartProjectionFactor.h
@@ -391,7 +391,7 @@ namespace gtsam {
             Point2 reprojectionError(camera.project(*point) - measured_.at(i));
             overallError += noise_->distance( reprojectionError.vector() );
           }
-          return sqrt(overallError);
+          return std::sqrt(overallError);
         }else{ // triangulation failed: we deactivate the factor, then the error should not contribute to the overall error
           return 0.0;
         }