From b0f26fd4b2359a1476aed8537bca6784b5649569 Mon Sep 17 00:00:00 2001
From: Evgeny Levinkov <levinkov@mpi-inf.mpg.de>
Date: Thu, 11 Feb 2016 15:38:43 +0100
Subject: [PATCH] changed functions to classes. Introduced RandError

---
 CMakeLists.txt                              |  15 +
 include/andres/partition-comparison.hxx     | 462 +++++++++-----------
 src/mex/andres_rand_index.cxx               |   2 +-
 src/mex/andres_variation_of_information.cxx |   2 +-
 src/unittest/partition-comparison.cxx       | 135 ++++--
 5 files changed, 335 insertions(+), 281 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3003aaf..81ca938 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,6 +4,20 @@ include_directories(include include/andres)
 file(GLOB headers include/andres/*.hxx)
 enable_testing()
 
+##############################################################################
+# C++11 support
+##############################################################################
+include(CheckCXXCompilerFlag)
+CHECK_CXX_COMPILER_FLAG("-std=c++11" COMPILER_SUPPORTS_CXX11)
+CHECK_CXX_COMPILER_FLAG("-std=c++0x" COMPILER_SUPPORTS_CXX0X)
+if(COMPILER_SUPPORTS_CXX11)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11")
+elseif(COMPILER_SUPPORTS_CXX0X)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++0x")
+else()
+    message(STATUS "The compiler ${CMAKE_CXX_COMPILER} has no C++11 support. Some functionality will not be available.")
+endif()
+
 find_package(Matlab QUIET)
 if(MATLAB_FOUND)
     INCLUDE_DIRECTORIES(${MATLAB_INCLUDE_DIR})
@@ -14,6 +28,7 @@ endif()
 
 add_executable(test-partition-comparison src/unittest/partition-comparison.cxx ${headers})
 add_test(test-partition-comparison test-partition-comparison)
+
 if(MATLAB_FOUND)
    add_library(andres_rand_index SHARED src/mex/andres_rand_index.cxx src/mex/andres_rand_index.def ${headers})
    target_link_libraries(andres_rand_index ${MATLAB_LIBRARIES})
diff --git a/include/andres/partition-comparison.hxx b/include/andres/partition-comparison.hxx
index 24580b7..cae81d7 100644
--- a/include/andres/partition-comparison.hxx
+++ b/include/andres/partition-comparison.hxx
@@ -8,274 +8,242 @@
 #include <cmath> // log
 #include <stdexcept> // runtime_error
 
+
 namespace andres {
 
-// interface
-template<class ITERATOR_0, class ITERATOR_1>
-    size_t matchingPairs(ITERATOR_0, ITERATOR_0, ITERATOR_1, const bool = false);
-template<class ITERATOR_0, class ITERATOR_1>
-    size_t matchingPairs(ITERATOR_0, ITERATOR_0, ITERATOR_1, const bool, size_t&);
-template<class ITERATOR_0, class ITERATOR_1>
-    double randIndex(ITERATOR_0, ITERATOR_0, ITERATOR_1, const bool = false);
-template<class ITERATOR_0, class ITERATOR_1>
-    double variationOfInformation(ITERATOR_0, ITERATOR_0, ITERATOR_1, const bool = false);
-
-// brute force code for unit tests
-template<class ITERATOR_0, class ITERATOR_1>
-    size_t matchingPairsBruteForce(ITERATOR_0, ITERATOR_0, ITERATOR_1, const bool = false);
-template<class ITERATOR_0, class ITERATOR_1>
-    size_t matchingPairsBruteForce(ITERATOR_0, ITERATOR_0, ITERATOR_1, const bool, size_t&);
-template<class ITERATOR_0, class ITERATOR_1>
-    double randIndexBruteForce(ITERATOR_0, ITERATOR_0, ITERATOR_1, const bool = false);
-
-// implementation
-
-template<class ITERATOR_0, class ITERATOR_1>
-inline size_t
-matchingPairsBruteForce
-(
-    ITERATOR_0 begin0,
-    ITERATOR_0 end0,
-    ITERATOR_1 begin1,
-    const bool ignoreDefaultLabel
-)
-{
-    size_t N;
-    return matchingPairsBruteForce(begin0, end0, begin1, ignoreDefaultLabel, N);
-}
-
-template<class ITERATOR_0, class ITERATOR_1>
-size_t
-matchingPairsBruteForce
-(
-    ITERATOR_0 begin0,
-    ITERATOR_0 end0,
-    ITERATOR_1 begin1,
-    const bool ignoreDefaultLabel,
-    size_t& N // output: number of elements which have a non-zero label in both partitions
-)
-{
-    typedef typename std::iterator_traits<ITERATOR_0>::value_type Label0;
-    typedef typename std::iterator_traits<ITERATOR_1>::value_type Label1;
-
-    size_t AB = 0;
-    if(ignoreDefaultLabel) {
-        N = 0;
-        ITERATOR_1 it1 = begin1;
-        for(ITERATOR_0 it0 = begin0; it0 != end0; ++it0, ++it1) {
-            if(*it0 != Label0() && *it1 != Label1()) {
-                ++N;
-                ITERATOR_1 it1b = it1 + 1;
-                for(ITERATOR_0 it0b = it0 + 1; it0b != end0; ++it0b, ++it1b) {
-                    if(*it0b != Label0() && *it1b != Label1()) {
-                        if((*it0 == *it0b && *it1 == *it1b) || (*it0 != *it0b && *it1 != *it1b)) {
-                            ++AB;
-                        }
-                    }
+template<class T = double>
+class RandError {
+public:
+    typedef T value_type;
+
+    template<class ITERATOR_TRUTH, class ITERATOR_PRED>
+    RandError(ITERATOR_TRUTH begin0, ITERATOR_TRUTH end0, ITERATOR_PRED begin1, bool ignoreDefaultLabel = false)
+    {
+        typedef typename std::iterator_traits<ITERATOR_TRUTH>::value_type Label0;
+        typedef typename std::iterator_traits<ITERATOR_PRED>::value_type Label1;
+        typedef std::pair<Label0, Label1> Pair;
+        typedef std::map<Pair, size_t> OverlapMatrix;
+        typedef std::map<Label0, size_t> TruthSumMap;
+        typedef std::map<Label1, size_t> PredSumMap;
+
+        OverlapMatrix n;
+        TruthSumMap truthSum;
+        PredSumMap predSum;
+
+        elements_ = std::distance(begin0, end0);
+
+        if (ignoreDefaultLabel)
+        {
+            elements_ = 0;
+
+            for(; begin0 != end0; ++begin0, ++begin1)
+                if (*begin0 != Label0() && *begin1 != Label1())
+                {
+                    ++n[Pair(*begin0, *begin1)];
+                    ++truthSum[*begin0];
+                    ++predSum[*begin1];
+                    ++elements_;
                 }
-            }
+
+            if (elements_ == 0)
+                throw std::runtime_error("No element is labeled in both partitions.");
         }
-    }
-    else {
-        N = std::distance(begin0, end0);
-        ITERATOR_1 it1 = begin1;
-        for(ITERATOR_0 it0 = begin0; it0 != end0; ++it0, ++it1) {
-            ITERATOR_1 it1b = it1 + 1;
-            for(ITERATOR_0 it0b = it0 + 1; it0b != end0; ++it0b, ++it1b) {
-                if( (*it0 == *it0b && *it1 == *it1b) || (*it0 != *it0b && *it1 != *it1b) ) {
-                    ++AB;
-                }
+        else
+            for(; begin0 != end0; ++begin0, ++begin1)
+            {
+                ++n[Pair(*begin0, *begin1)];
+                ++truthSum[*begin0];
+                ++predSum[*begin1];
             }
+
+        for (auto const& it : predSum)
+            falseJoins_ += it.second * it.second;
+
+        for (auto const& it : truthSum)
+            falseCuts_ += it.second * it.second;
+
+        for (auto const& it : n)
+        {
+            const size_t i = it.first.first;
+            const size_t j = it.first.second;
+            const size_t n_ij = it.second;
+
+            trueJoins_ += n_ij * (n_ij - 1) / 2;
+            falseCuts_ -= n_ij * n_ij;
+            falseJoins_ -= n_ij * n_ij;
         }
 
-    }
-    return AB;
-}
-
-template<class ITERATOR_0, class ITERATOR_1>
-inline size_t
-matchingPairs
-(
-    ITERATOR_0 begin0,
-    ITERATOR_0 end0,
-    ITERATOR_1 begin1,
-    const bool ignoreDefaultLabel
-)
-{
-    size_t N;
-    return matchingPairs(begin0, end0, begin1, ignoreDefaultLabel, N);
-}
-
-template<class ITERATOR_0, class ITERATOR_1>
-size_t
-matchingPairs
-(
-    ITERATOR_0 begin0,
-    ITERATOR_0 end0,
-    ITERATOR_1 begin1,
-    const bool ignoreDefaultLabel,
-    size_t& N // output: number of elements which have a non-zero label in both partitions
-)
-{
-    typedef typename std::iterator_traits<ITERATOR_0>::value_type Label0;
-    typedef typename std::iterator_traits<ITERATOR_1>::value_type Label1;
-    typedef std::pair<Label0, Label1> Pair;
-    typedef std::map<Pair, size_t> OverlapMatrix;
-    typedef std::map<Label0, size_t> RowSumMap;
-    typedef std::map<Label1, size_t> ColumnSumMap;
-
-    OverlapMatrix n;
-    RowSumMap rowSum;
-    ColumnSumMap columnSum;
-    if(ignoreDefaultLabel) {
-        N = 0;
-        for(; begin0 != end0; ++begin0, ++begin1) {
-            if(*begin0 != Label0() && *begin1 != Label1()) {
-                ++n[Pair(*begin0, *begin1)];
-                ++rowSum[*begin0];
-                ++columnSum[*begin1];
-                ++N;
-            }
+        falseJoins_ /= 2;
+        falseCuts_ /= 2;
+
+        trueCuts_ = pairs() - joinsInPrediction() - falseCuts_;
+    }
+
+    size_t elements() const
+        { return elements_; }
+    size_t pairs() const
+        { return elements_ * (elements_ - 1) / 2; }
+
+    size_t trueJoins() const
+        { return trueJoins_; }
+    size_t trueCuts() const
+        { return trueCuts_; }
+    size_t falseJoins() const
+        { return falseJoins_; }
+    size_t falseCuts() const
+        { return falseCuts_; }
+
+    size_t joinsInPrediction() const
+        { return trueJoins_ + falseJoins_; }
+    size_t cutsInPrediction() const
+        { return trueCuts_ + falseCuts_; }
+    size_t joinsInTruth() const
+        { return trueJoins_ + falseCuts_; }
+    size_t cutsInTruth() const
+        { return trueCuts_ + falseJoins_; }
+
+    value_type recallOfCuts() const
+        {
+            if(cutsInTruth() == 0)
+                return 1;
+            else
+                return static_cast<value_type>(trueCuts()) / cutsInTruth();
         }
-    }
-    else {
-        N = std::distance(begin0, end0);
-        for(; begin0 != end0; ++begin0, ++begin1) {
-            ++n[Pair(*begin0, *begin1)];
-            ++rowSum[*begin0];
-            ++columnSum[*begin1];
+    value_type precisionOfCuts() const
+        {
+            if(cutsInPrediction() == 0)
+                return 1;
+            else
+                return static_cast<value_type>(trueCuts()) / cutsInPrediction();
         }
-    }
-    size_t A = 0.0;
-    for(typename OverlapMatrix::const_iterator it = n.begin(); it != n.end(); ++it) {
-        A += (it->second) * (it->second - 1);
-    }
-    size_t B = N * N;
-    for(typename OverlapMatrix::const_iterator it = n.begin(); it != n.end(); ++it) {
-        B += it->second * it->second;
-    }
-    for(typename RowSumMap::const_iterator it = rowSum.begin(); it != rowSum.end(); ++it) {
-        B -= it->second * it->second;
-    }
-    for(typename ColumnSumMap::const_iterator it = columnSum.begin(); it != columnSum.end(); ++it) {
-        B -= it->second * it->second;
-    }
-    return (A + B) / 2;
-}
-
-template<class ITERATOR_0, class ITERATOR_1>
-inline double
-randIndexBruteForce
-(
-    ITERATOR_0 begin0,
-    ITERATOR_0 end0,
-    ITERATOR_1 begin1,
-    const bool ignoreDefaultLabel
-)
-{
-    size_t N;
-    const size_t n = matchingPairsBruteForce(begin0, end0, begin1, ignoreDefaultLabel, N);
-    if(N == 0) {
-        throw std::runtime_error("No element is labeled in both partitions.");
-    }
-    else {
-        return static_cast<double>(n) * 2 / static_cast<double>(N * (N-1));
-    }
-}
-
-template<class ITERATOR_0, class ITERATOR_1>
-inline double
-randIndex
-(
-    ITERATOR_0 begin0,
-    ITERATOR_0 end0,
-    ITERATOR_1 begin1,
-    const bool ignoreDefaultLabel
-)
-{
-    size_t N;
-    const size_t n = matchingPairs(begin0, end0, begin1, ignoreDefaultLabel, N);
-    if(N == 0) {
-        throw std::runtime_error("No element is labeled in both partitions.");
-    }
-    else {
-        return static_cast<double>(n) * 2 / static_cast<double>(N * (N-1));
-    }
-}
-
-template<class ITERATOR_0, class ITERATOR_1>
-double
-variationOfInformation
-(
-    ITERATOR_0 begin0,
-    ITERATOR_0 end0,
-    ITERATOR_1 begin1,
-    const bool ignoreDefaultLabel
-)
-{
-    typedef typename std::iterator_traits<ITERATOR_0>::value_type Label0;
-    typedef typename std::iterator_traits<ITERATOR_1>::value_type Label1;
-    typedef std::pair<Label0, Label1> Pair;
-    typedef std::map<Pair, double> PMatrix;
-    typedef std::map<Label0, double> PVector0;
-    typedef std::map<Label1, double> PVector1;
-
-    // count
-    size_t N = std::distance(begin0, end0);
-    PMatrix pjk;
-    PVector0 pj;
-    PVector1 pk;
-    if(ignoreDefaultLabel) {
-        N = 0;
-        for(; begin0 != end0; ++begin0, ++begin1) {
-            if(*begin0 != Label0() && *begin1 != Label1()) {
+
+    value_type recallOfJoins() const
+        {
+            if(joinsInTruth() == 0)
+                return 1;
+            else
+                return static_cast<value_type>(trueJoins()) / joinsInTruth();
+        }
+    value_type precisionOfJoins() const
+        {
+            if(joinsInPrediction() == 0)
+                return 1;
+            else
+                return static_cast<value_type>(trueJoins()) / joinsInPrediction();
+        }
+
+    value_type error() const
+        { return static_cast<value_type>(falseJoins() + falseCuts()) / pairs(); }
+    value_type index() const
+        { return static_cast<value_type>(trueJoins() + trueCuts()) / pairs(); }
+
+private:
+    size_t elements_;
+    size_t trueJoins_ { size_t() };
+    size_t trueCuts_ { size_t() };
+    size_t falseJoins_ { size_t() };
+    size_t falseCuts_ { size_t() };
+};
+
+template<class T = double>
+class VariationOfInformation {
+public:
+    typedef T value_type;
+
+    template<class ITERATOR_TRUTH, class ITERATOR_PRED>
+    VariationOfInformation(ITERATOR_TRUTH begin0, ITERATOR_TRUTH end0, ITERATOR_PRED begin1, bool ignoreDefaultLabel = false)
+    {
+        typedef typename std::iterator_traits<ITERATOR_TRUTH>::value_type Label0;
+        typedef typename std::iterator_traits<ITERATOR_PRED>::value_type Label1;
+        typedef std::pair<Label0, Label1> Pair;
+        typedef std::map<Pair, double> PMatrix;
+        typedef std::map<Label0, double> PVector0;
+        typedef std::map<Label1, double> PVector1;
+
+        // count
+        size_t N = std::distance(begin0, end0);
+
+        PMatrix pjk;
+        PVector0 pj;
+        PVector1 pk;
+
+        if (ignoreDefaultLabel)
+        {
+            N = 0;
+
+            for (; begin0 != end0; ++begin0, ++begin1)
+                if (*begin0 != Label0() && *begin1 != Label1())
+                {
+                    ++pj[*begin0];
+                    ++pk[*begin1];
+                    ++pjk[Pair(*begin0, *begin1)];
+                    ++N;
+                }
+        }
+        else
+            for (; begin0 != end0; ++begin0, ++begin1)
+            {
                 ++pj[*begin0];
                 ++pk[*begin1];
                 ++pjk[Pair(*begin0, *begin1)];
-                ++N;
             }
+
+        // normalize
+        for (auto& p : pj)
+            p.second /= N;
+        
+        for (auto& p : pk)
+            p.second /= N;
+        
+        for (auto& p : pjk)
+            p.second /= N;
+
+        // compute information
+        auto H0 = value_type();
+        for (auto const& p : pj)
+            H0 -= p.second * std::log2(p.second);
+        
+        auto H1 = value_type();
+        for (auto const& p : pk)
+            H1 -= p.second * std::log2(p.second);
+        
+        auto I = value_type();
+        for (auto const& p : pjk)
+        {
+            auto j = p.first.first;
+            auto k = p.first.second;
+            auto pjk_here = p.second;
+            auto pj_here = pj[j];
+            auto pk_here = pk[k];
+
+            I += pjk_here * std::log2( pjk_here / (pj_here * pk_here) );
         }
-    }
-    else {
-        for(; begin0 != end0; ++begin0, ++begin1) {
-            ++pj[*begin0];
-            ++pk[*begin1];
-            ++pjk[Pair(*begin0, *begin1)];
-        }
-    }
 
-    // normalize
-    for(typename PVector0::iterator it = pj.begin(); it != pj.end(); ++it) {
-        it->second /= N;
-    }
-    for(typename PVector1::iterator it = pk.begin(); it != pk.end(); ++it) {
-        it->second /= N;
-    }
-    for(typename PMatrix::iterator it = pjk.begin(); it != pjk.end(); ++it) {
-        it->second /= N;
+        value_ = H0 + H1 - 2.0 * I;
+        precision_ = H1 - I;
+        recall_ = H0 - I;
     }
 
-    // compute information
-    double H0 = 0.0;
-    for(typename PVector0::const_iterator it = pj.begin(); it != pj.end(); ++it) {
-        H0 -= it->second * std::log(it->second);
+    value_type value() const
+    {
+        return value_;
     }
-    double H1 = 0.0;
-    for(typename PVector1::const_iterator it = pk.begin(); it != pk.end(); ++it) {
-        H1 -= it->second * std::log(it->second);
+
+    value_type valueFalseCut() const
+    {
+        return precision_;
     }
-    double I = 0.0;
-    for(typename PMatrix::const_iterator it = pjk.begin(); it != pjk.end(); ++it) {
-        const Label0 j = it->first.first;
-        const Label1 k = it->first.second;
-        const double pjk_here = it->second;
-        const double pj_here = pj[j];
-        const double pk_here = pk[k];
-        I += pjk_here * std::log( pjk_here / (pj_here * pk_here) );
+
+    value_type valueFalseJoin() const
+    {
+        return recall_;
     }
 
-    return H0 + H1 - 2.0 * I;
-}
+private:
+    value_type value_;
+    value_type precision_;
+    value_type recall_;
+};
 
 } // namespace andres
 
diff --git a/src/mex/andres_rand_index.cxx b/src/mex/andres_rand_index.cxx
index 8ea68fa..f1730b7 100644
--- a/src/mex/andres_rand_index.cxx
+++ b/src/mex/andres_rand_index.cxx
@@ -20,7 +20,7 @@ matlabRandIndexHelper(
     const size_t n = mxGetNumberOfElements(array0);
     const T* p0 = static_cast<const T*>(mxGetData(array0));
     const T* p1 = static_cast<const T*>(mxGetData(array1));
-    return andres::randIndex(p0, p0 + n, p1, true); // ignores default label 0
+    return andres::RandError<>(p0, p0 + n, p1, true).index(); // ignores default label 0
 }
 
 void mexFunction(
diff --git a/src/mex/andres_variation_of_information.cxx b/src/mex/andres_variation_of_information.cxx
index bf2e158..2665e62 100644
--- a/src/mex/andres_variation_of_information.cxx
+++ b/src/mex/andres_variation_of_information.cxx
@@ -20,7 +20,7 @@ matlabVIHelper(
     const size_t n = mxGetNumberOfElements(array0);
     const T* p0 = static_cast<const T*>(mxGetData(array0));
     const T* p1 = static_cast<const T*>(mxGetData(array1));
-    return andres::variationOfInformation(p0, p0 + n, p1, true); // ignores default label 0
+    return andres::VariationOfInformation<>(p0, p0 + n, p1, true).value(); // ignores default label 0
 }
 
 void mexFunction(
diff --git a/src/unittest/partition-comparison.cxx b/src/unittest/partition-comparison.cxx
index b9fbc67..743dd56 100644
--- a/src/unittest/partition-comparison.cxx
+++ b/src/unittest/partition-comparison.cxx
@@ -11,66 +11,137 @@
     throw std::logic_error(s.str().c_str()); \
 }
 
+// implementation
+template<class ITERATOR_0, class ITERATOR_1>
+inline size_t
+matchingPairsBruteForce
+(
+    ITERATOR_0 begin0,
+    ITERATOR_0 end0,
+    ITERATOR_1 begin1,
+    const bool ignoreDefaultLabel = false
+)
+{
+    size_t N;
+    return matchingPairsBruteForce(begin0, end0, begin1, ignoreDefaultLabel, N);
+}
+
+template<class ITERATOR_0, class ITERATOR_1>
+size_t
+matchingPairsBruteForce
+(
+    ITERATOR_0 begin0,
+    ITERATOR_0 end0,
+    ITERATOR_1 begin1,
+    const bool ignoreDefaultLabel,
+    size_t& N // output: number of elements which have a non-zero label in both partitions
+)
+{
+    typedef typename std::iterator_traits<ITERATOR_0>::value_type Label0;
+    typedef typename std::iterator_traits<ITERATOR_1>::value_type Label1;
+
+    size_t AB = 0;
+    if(ignoreDefaultLabel) {
+        N = 0;
+        ITERATOR_1 it1 = begin1;
+        for(ITERATOR_0 it0 = begin0; it0 != end0; ++it0, ++it1) {
+            if(*it0 != Label0() && *it1 != Label1()) {
+                ++N;
+                ITERATOR_1 it1b = it1 + 1;
+                for(ITERATOR_0 it0b = it0 + 1; it0b != end0; ++it0b, ++it1b) {
+                    if(*it0b != Label0() && *it1b != Label1()) {
+                        if((*it0 == *it0b && *it1 == *it1b) || (*it0 != *it0b && *it1 != *it1b)) {
+                            ++AB;
+                        }
+                    }
+                }
+            }
+        }
+    }
+    else {
+        N = std::distance(begin0, end0);
+        ITERATOR_1 it1 = begin1;
+        for(ITERATOR_0 it0 = begin0; it0 != end0; ++it0, ++it1) {
+            ITERATOR_1 it1b = it1 + 1;
+            for(ITERATOR_0 it0b = it0 + 1; it0b != end0; ++it0b, ++it1b) {
+                if( (*it0 == *it0b && *it1 == *it1b) || (*it0 != *it0b && *it1 != *it1b) ) {
+                    ++AB;
+                }
+            }
+        }
+
+    }
+    return AB;
+}
+
+template<class ITERATOR_0, class ITERATOR_1>
+inline double
+randIndexBruteForce
+(
+    ITERATOR_0 begin0,
+    ITERATOR_0 end0,
+    ITERATOR_1 begin1,
+    const bool ignoreDefaultLabel = false
+)
+{
+    size_t N;
+    const size_t n = matchingPairsBruteForce(begin0, end0, begin1, ignoreDefaultLabel, N);
+    if(N == 0) {
+        throw std::runtime_error("No element is labeled in both partitions.");
+    }
+    else {
+        return static_cast<double>(n) * 2 / static_cast<double>(N * (N-1));
+    }
+}
+
 int main() {
     {
         size_t p0[4] = {0, 1, 1, 1};
         size_t p1[4] = {0, 1, 2, 2};
 
-        TEST(andres::matchingPairs(p0, p0+4, p1) == 4);
-        TEST(andres::matchingPairs(p0, p0+4, p1, true) == 1);
-
-        TEST(andres::randIndex(p0, p0+4, p1) == 2.0 / 3.0);
-        TEST(andres::randIndex(p0, p0+4, p1, true) == 1.0 / 3.0);
-        TEST(andres::randIndex(p0, p0+4, p1) == andres::randIndexBruteForce(p0, p0+4, p1));
+        TEST(andres::RandError<>(p0, p0+4, p1).index() == 2.0 / 3.0);
+        TEST(andres::RandError<>(p0, p0+4, p1, true).index() == 1.0 / 3.0);
+        TEST(andres::RandError<>(p0, p0+4, p1).index() == randIndexBruteForce(p0, p0+4, p1));
     }
     {
         size_t p0[10] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
         size_t p1[10] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
 
-        TEST(andres::matchingPairs(p0, p0+10, p1) == 0);
-        TEST(andres::matchingPairs(p0, p0+10, p1, true) == 0);
-        TEST(andres::matchingPairs(p0, p0+10, p1) == andres::matchingPairsBruteForce(p0, p0+10, p1));
-        TEST(andres::matchingPairs(p0, p0+10, p1, true) == andres::matchingPairsBruteForce(p0, p0+10, p1, true));
-
-        TEST(andres::randIndex(p0, p0+10, p1) == 0.0);
-        TEST(andres::randIndex(p0, p0+10, p1) == andres::randIndexBruteForce(p0, p0+10, p1));
+        TEST(andres::RandError<>(p0, p0+10, p1).index() == 0.0);
+        TEST(andres::RandError<>(p0, p0+10, p1).index() == randIndexBruteForce(p0, p0+10, p1));
         try {
-            andres::randIndex(p0, p0+10, p1, true);
+            andres::RandError<>(p0, p0+10, p1, true).index();
             TEST(false);
         }
         catch(std::runtime_error& e) {
         }
 
-        TEST(andres::variationOfInformation(p0, p0+10, p1, true) == 0.0);
+        TEST(andres::VariationOfInformation<>(p0, p0+10, p1, true).value() == 0.0);
     }
     {
         size_t p0[10] = {0, 0, 0, 0, 0, 1, 1, 1, 1, 1};
         size_t p1[10] = {6, 6, 6, 6, 6, 7, 7, 7, 7, 7};
 
-        TEST(andres::matchingPairs(p0, p0+10, p1) == 45);
-        TEST(andres::matchingPairs(p0, p0+10, p1, true) == 10);
-        TEST(andres::matchingPairs(p0, p0+10, p1) == andres::matchingPairsBruteForce(p0, p0+10, p1));
-        TEST(andres::matchingPairs(p0, p0+10, p1, true) == andres::matchingPairsBruteForce(p0, p0+10, p1, true));
+        TEST(andres::RandError<>(p0, p0+10, p1).index() == 1.0);
+        TEST(andres::RandError<>(p0, p0+10, p1, true).index() == 1.0);
+        TEST(andres::RandError<>(p0, p0+10, p1).index() == randIndexBruteForce(p0, p0+10, p1));
+        TEST(andres::RandError<>(p0, p0+10, p1, true).index() == randIndexBruteForce(p0, p0+10, p1, true));
 
-        TEST(andres::randIndex(p0, p0+10, p1) == 1.0);
-        TEST(andres::randIndex(p0, p0+10, p1, true) == 1.0);
-        TEST(andres::randIndex(p0, p0+10, p1) == andres::randIndexBruteForce(p0, p0+10, p1));
-        TEST(andres::randIndex(p0, p0+10, p1, true) == andres::randIndexBruteForce(p0, p0+10, p1, true));
-
-        TEST(andres::variationOfInformation(p0, p0+10, p1) == 0.0)
-        TEST(andres::variationOfInformation(p0, p0+10, p1, true) == 0.0)
+        TEST(andres::VariationOfInformation<>(p0, p0+10, p1).value() == 0.0)
+        TEST(andres::VariationOfInformation<>(p0, p0+10, p1, true).value() == 0.0)
     }
     {
         size_t p0[10] = {0, 0, 0, 0, 4, 4, 4, 4, 8, 9};
         size_t p1[10] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
 
-        TEST(andres::matchingPairs(p0, p0+10, p1) == 33);
-        TEST(andres::matchingPairs(p0, p0+10, p1, true) == 9);
-        TEST(andres::matchingPairs(p0, p0+10, p1) == andres::matchingPairsBruteForce(p0, p0+10, p1));
-        TEST(andres::matchingPairs(p0, p0+10, p1, true) == andres::matchingPairsBruteForce(p0, p0+10, p1, true));
+        TEST(andres::RandError<>(p0, p0+10, p1).index() == randIndexBruteForce(p0, p0+10, p1));
+        TEST(andres::RandError<>(p0, p0+10, p1, true).index() == randIndexBruteForce(p0, p0+10, p1, true));
+
+        TEST(andres::RandError<>(p0, p0+10, p1).index() == andres::RandError<>(p1, p1+10, p0).index());
+        TEST(andres::RandError<>(p0, p0+10, p1, true).index() == andres::RandError<>(p1, p1+10, p0, true).index());
 
-        TEST(andres::randIndex(p0, p0+10, p1) == andres::randIndexBruteForce(p0, p0+10, p1));
-        TEST(andres::randIndex(p0, p0+10, p1, true) == andres::randIndexBruteForce(p0, p0+10, p1, true));
+        TEST(andres::VariationOfInformation<>(p0, p0+10, p1).value() == andres::VariationOfInformation<>(p1, p1+10, p0).value());
+        TEST(andres::VariationOfInformation<>(p0, p0+10, p1, true).value() == andres::VariationOfInformation<>(p1, p1+10, p0, true).value());
     }
 
     return 0;