diff --git a/cpp/FactorGraph.h b/cpp/FactorGraph.h
index fb0193c75..f206f0be3 100644
--- a/cpp/FactorGraph.h
+++ b/cpp/FactorGraph.h
@@ -100,8 +100,6 @@ namespace gtsam {
 			return !(indices_.find(key)==indices_.end());
 		}
 
-		/** check whether a variable is a singleton, i.e. it only involve*/
-
 		/** remove singleton variables and the related factors */
 		std::pair<FactorGraph<Factor>, std::set<Symbol> > removeSingletons();
 
diff --git a/cpp/Rot2.cpp b/cpp/Rot2.cpp
index 260e0edb9..03249e17d 100644
--- a/cpp/Rot2.cpp
+++ b/cpp/Rot2.cpp
@@ -17,8 +17,11 @@ namespace gtsam {
 
 	/* ************************************************************************* */
 	Rot2 Rot2::fromCosSin(double c, double s) {
-		if (fabs(c * c + s * s - 1.0) > 1e-9) throw std::invalid_argument(
-				"Rot2::fromCosSin: needs cos/sin pair");
+		if (fabs(c * c + s * s - 1.0) > 1e-9) {
+    	double norm_cs = sqrt(c*c + s*s);
+    	c = c/norm_cs;
+    	s = s/norm_cs;
+		}
 		return Rot2(c, s);
 	}