2 files changed, 8 insertions, 0 deletions
diff --git a/src/feature.cpp b/src/feature.cpp
index 49a6262..136f820 100644
--- a/src/feature.cpp
+++ b/src/feature.cpp
@@ -506,3 +506,10 @@ Feature::sane ( )
     return rv ;
 }		/* -----  end of method Feature::sane  ----- */
 
+void
+Feature::dx ( const Vector3d &del )
+{
+    X += del;
+    return ;
+}		/* -----  end of method Feature::dx  ----- */
+
diff --git a/src/feature.h b/src/feature.h
index 3e99bab..b921d8b 100644
--- a/src/feature.h
+++ b/src/feature.h
@@ -33,6 +33,7 @@ class Feature
 
         /* ====================  MUTATORS      ======================================= */
         void motionModel ( const Vector3d &ang, const Vector3d &vel, const double dt);
+        void dx( const Vector3d &del);
 
         /* ====================  OPERATORS     ======================================= */
         bool sane();