From a9ba1da877051632154bf6b6090f91ce402ac6ce Mon Sep 17 00:00:00 2001
From: Jose Luis Blanco Claraco <joseluisblancoc@gmail.com>
Date: Fri, 22 Apr 2022 12:37:48 +0200
Subject: [PATCH] Revert "fix derivative"

This reverts commit 42b795c769e66dacc24cbe8b13309cdfb3506fc2.
---
 gtsam/linear/LossFunctions.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/gtsam/linear/LossFunctions.cpp b/gtsam/linear/LossFunctions.cpp
index 6573beac9..7307c4a68 100644
--- a/gtsam/linear/LossFunctions.cpp
+++ b/gtsam/linear/LossFunctions.cpp
@@ -350,8 +350,8 @@ double DCS::weight(double distance) const {
   const double e2 = distance*distance;
   if (e2 > c_)
   {
-    const double w = c_/(c_ + e2);
-    return 2.0*w*w;
+    const double w = 2.0*c_/(c_ + e2);
+    return w*w;
   }
 
   return 1.0;