From b51005043cb21518c070e0b4744d885bf7040b67 Mon Sep 17 00:00:00 2001
From: hrocho <hrocho@vodacionline.sk>
Date: Mon, 29 Jan 2018 18:54:24 +0100
Subject: [PATCH] mf

---
 structures.h              |  6 ++++++
 tests/test_structures.cpp | 21 +++++++++++++++------
 2 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/structures.h b/structures.h
index 6332d5b..b6053a4 100644
--- a/structures.h
+++ b/structures.h
@@ -117,6 +117,12 @@ namespace catima{
              */
             double weight_fraction(int i) const {return (atoms[i].stn<1.0)?atoms[i].stn:atoms[i].stn*atoms[i].A/M();};
 
+            /**
+             * return molar fraction of i-th element
+             * @return molar fraction
+             */
+            double molar_fraction(int i) const {return (atoms[i].stn<1.0)?atoms[i].stn*M()/atoms[i].A:atoms[i].stn;};
+
             /**
               * @return number of components in Material
               */
diff --git a/tests/test_structures.cpp b/tests/test_structures.cpp
index 951202a..58cbb9e 100644
--- a/tests/test_structures.cpp
+++ b/tests/test_structures.cpp
@@ -234,26 +234,35 @@ const lest::test specification[] =
     },
     CASE("fraction calculation"){
         catima::Material water1({
-                        {0, 1, 0.111894},
-                        {0, 8, 0.888106}
+                        {0, 1, 0.111898},
+                        {0, 8, 0.888102}
                         });
         catima::Material water2({
                         {0, 1, 2},
                         {0, 8, 1}
                         });
 
-        EXPECT(water1.weight_fraction(0)==0.111894);
-        EXPECT(water2.weight_fraction(0)==approx(water1.weight_fraction(0)).R(1e-3));
-        EXPECT(water1.weight_fraction(1)==0.888106);
-        EXPECT(water2.weight_fraction(1)==approx(water1.weight_fraction(1)).R(1e-3));
+        EXPECT(water1.weight_fraction(0)==0.111898);
+        EXPECT(water2.weight_fraction(0)==approx(water1.weight_fraction(0)).R(1e-5));
+        EXPECT(water1.weight_fraction(1)==0.888102);
+        EXPECT(water2.weight_fraction(1)==approx(water1.weight_fraction(1)).R(1e-5));
         EXPECT(water2.M()==approx(18).epsilon(0.1));
 
         EXPECT(water1.M()==approx(6.0,0.1));
         EXPECT(water2.M()==approx(18,0.1));
 
+        EXPECT(water1.molar_fraction(0)==approx(2.0/3.0).R(1e-5));
+        EXPECT(water2.molar_fraction(0)==approx(2.0).R(1e-5));
+        EXPECT(water1.molar_fraction(1)==approx(1.0/3.0).R(1e-5));
+        EXPECT(water2.molar_fraction(1)==approx(1.0).R(1e-5));
+        EXPECT(water1.molar_fraction(0)/water1.molar_fraction(1)==approx(2.0).R(1e-5));
+        EXPECT(water2.molar_fraction(0)/water2.molar_fraction(1)==approx(2.0).R(1e-5));
+
+
         catima::Material mat({12.0,6,1});
         EXPECT(mat.M()==approx(12.0,0.001));
         EXPECT(mat.weight_fraction(0)==approx(1.0).R(1e-6));
+
     }
 };