From 3d68672b20d168e57b51401802c3bcb334dfe578 Mon Sep 17 00:00:00 2001
From: Richard Roberts <richard.jw.roberts@gmail.com>
Date: Wed, 21 Dec 2011 17:47:03 +0000
Subject: [PATCH] Constant error of 2*fx instead of 0 when point is behind
 camera

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

diff --git a/gtsam/slam/ProjectionFactor.h b/gtsam/slam/ProjectionFactor.h
index 6940e367f..73d18a7e6 100644
--- a/gtsam/slam/ProjectionFactor.h
+++ b/gtsam/slam/ProjectionFactor.h
@@ -92,7 +92,7 @@ namespace gtsam {
 			  if (H2) *H2 = zeros(2,3);
 			  cout << e.what() << ": Landmark "<< this->key2_.index() <<
 			      " moved behind camera " << this->key1_.index() << endl;
-			  return zero(2);
+			  return ones(2) * 2.0 * K_->fx();
 			}
 		}