From b1c01f2140e0c657531ed23bf6194c7e47f6b4e4 Mon Sep 17 00:00:00 2001
From: vbd <vbd>
Date: Thu, 23 Aug 2007 14:21:58 +0000
Subject: [PATCH] staffan : 	* added epsilonEqualRelative for better
 equality checing of doubles

---
 src/INTERP_KERNEL/VectorUtils.hxx | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/INTERP_KERNEL/VectorUtils.hxx b/src/INTERP_KERNEL/VectorUtils.hxx
index f8e58d9d8..a85525de0 100644
--- a/src/INTERP_KERNEL/VectorUtils.hxx
+++ b/src/INTERP_KERNEL/VectorUtils.hxx
@@ -55,9 +55,22 @@ namespace INTERP_UTILS
 
   inline bool epsilonEqual(const double x, const double y, const double errTol = 1.0e-12)
   {
-    return std::abs(x - y) < errTol;
+    return std::abs(x - y) <= errTol;
+  }
+
+  inline bool epsilonEqualRelative(const double x, const double y, const double relTol = 1.0e-6, const double absTol = 1.0e-17)
+  {
+    // necessary for comparing values close to zero
+    // in order to avoid division
+    if(std::abs(x - y) < absTol)
+      {
+	return true;
+      }
+
+    const double relError = std::abs((x - y) / std::max(x, y));
+
+    return relError <= relTol;
   }
-  
 
 };
 
-- 
2.39.2