Refactor base algorithm

This commit is contained in:
2022-12-08 22:28:21 +01:00
parent c4e5cf1629
commit 4939a5b673
25 changed files with 538 additions and 1130 deletions

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@@ -1,41 +1,20 @@
#include "CPPFImdlp.h"
#include <numeric>
#include <iostream>
#include <algorithm>
#include <set>
#include "CPPFImdlp.h"
#include "Metrics.h"
namespace mdlp {
ostream& operator << (ostream& os, const cutPoint_t& cut)
CPPFImdlp::CPPFImdlp(): proposal(true), debug(false), indices(indices_t()), y(labels()), metrics(Metrics(y, indices))
{
os << cut.classNumber << " -> (" << cut.start << ", " << cut.end <<
") - (" << cut.fromValue << ", " << cut.toValue << ") "
<< endl;
return os;
}
CPPFImdlp::CPPFImdlp(): proposal(true), precision(6), debug(false)
CPPFImdlp::CPPFImdlp(bool proposal, bool debug): proposal(proposal), debug(debug), indices(indices_t()), y(labels()), metrics(Metrics(y, indices))
{
divider = pow(10, precision);
numClasses = 0;
}
CPPFImdlp::CPPFImdlp(bool proposal, int precision, bool debug): proposal(proposal), precision(precision), debug(debug)
{
divider = pow(10, precision);
numClasses = 0;
}
CPPFImdlp::~CPPFImdlp()
= default;
samples CPPFImdlp::getCutPoints()
{
samples output(cutPoints.size());
::transform(cutPoints.begin(), cutPoints.end(), output.begin(),
[](cutPoint_t cut) { return cut.toValue; });
return output;
}
labels CPPFImdlp::getDiscretizedValues()
{
return xDiscretized;
}
CPPFImdlp& CPPFImdlp::fit(samples& X_, labels& y_)
{
X = X_;
@@ -47,227 +26,78 @@ namespace mdlp {
throw invalid_argument("X and y must have at least one element");
}
indices = sortIndices(X_);
xDiscretized = labels(X.size(), -1);
numClasses = Metrics::numClasses(y, indices, 0, X.size());
if (proposal) {
computeCutPointsProposal();
} else {
computeCutPointsOriginal();
}
filterCutPoints();
// Apply cut points to the input vector
for (auto cut : cutPoints) {
for (size_t i = cut.start; i < cut.end; i++) {
xDiscretized[indices[i]] = cut.classNumber;
}
}
metrics.setData(y, indices);
computeCutPoints(0, X.size());
return *this;
}
bool CPPFImdlp::evaluateCutPoint(cutPoint_t rest, cutPoint_t candidate)
void CPPFImdlp::computeCutPoints(size_t start, size_t end)
{
int cut;
if (end - start < 2)
return;
cut = getCandidate(start, end);
if (cut == -1 || !mdlp(start, cut, end)) {
// cut.value == -1 means that there is no candidate in the interval
// No boundary found, so we add both ends of the interval as cutpoints
// because they were selected by the algorithm before
if (start != 0)
cutPoints.push_back((X[indices[start]] + X[indices[start - 1]]) / 2);
if (end != X.size())
cutPoints.push_back((X[indices[end]] + X[indices[end - 1]]) / 2);
return;
}
computeCutPoints(start, cut);
computeCutPoints(cut, end);
}
long int CPPFImdlp::getCandidate(size_t start, size_t end)
{
long int candidate = -1, elements = end - start;
precision_t entropy_left, entropy_right, minEntropy = numeric_limits<precision_t>::max();
for (auto idx = start + 1; idx < end; idx++) {
// Cutpoints are always on boudndaries
if (y[indices[idx]] == y[indices[idx - 1]])
continue;
entropy_left = precision_t(idx - start) / elements * metrics.entropy(start, idx);
entropy_right = precision_t(end - idx) / elements * metrics.entropy(idx, end);
if (entropy_left + entropy_right < minEntropy) {
minEntropy = entropy_left + entropy_right;
candidate = idx;
}
}
return candidate;
}
bool CPPFImdlp::mdlp(size_t start, size_t cut, size_t end)
{
int k, k1, k2;
float ig, delta;
float ent, ent1, ent2;
auto N = float(rest.end - rest.start);
precision_t ig, delta;
precision_t ent, ent1, ent2;
auto N = precision_t(end - start);
if (N < 2) {
return false;
}
k = Metrics::numClasses(y, indices, rest.start, rest.end);
k1 = Metrics::numClasses(y, indices, rest.start, candidate.end);
k2 = Metrics::numClasses(y, indices, candidate.end, rest.end);
ent = Metrics::entropy(y, indices, rest.start, rest.end, numClasses);
ent1 = Metrics::entropy(y, indices, rest.start, candidate.end, numClasses);
ent2 = Metrics::entropy(y, indices, candidate.end, rest.end, numClasses);
ig = Metrics::informationGain(y, indices, rest.start, rest.end, candidate.end, numClasses);
delta = log2(pow(3, float(k)) - 2) - (float(k) * ent - float(k1) * ent1 - float(k2) * ent2);
float term = 1 / N * (log2(N - 1) + delta);
if (debug) {
cout << "Rest: " << rest;
cout << "Candidate: " << candidate;
cout << "k=" << k << " k1=" << k1 << " k2=" << k2 << " ent=" << ent << " ent1=" << ent1 << " ent2=" << ent2 << endl;
cout << "ig=" << ig << " delta=" << delta << " N " << N << " term " << term << endl;
}
return (ig > term);
k = metrics.computeNumClasses(start, end);
k1 = metrics.computeNumClasses(start, cut);
k2 = metrics.computeNumClasses(cut, end);
ent = metrics.entropy(start, end);
ent1 = metrics.entropy(start, cut);
ent2 = metrics.entropy(cut, end);
ig = metrics.informationGain(start, cut, end);
delta = log2(pow(3, precision_t(k)) - 2) -
(precision_t(k) * ent - precision_t(k1) * ent1 - precision_t(k2) * ent2);
precision_t term = 1 / N * (log2(N - 1) + delta);
return ig > term;
}
void CPPFImdlp::filterCutPoints()
cutPoints_t CPPFImdlp::getCutPoints()
{
cutPoints_t filtered;
cutPoint_t rest, item;
int classNumber = 0;
rest.start = 0;
rest.end = X.size();
rest.fromValue = numeric_limits<float>::lowest();
rest.toValue = numeric_limits<float>::max();
rest.classNumber = classNumber;
bool first = true;
for (size_t index = 0; index < size_t(cutPoints.size()); index++) {
item = cutPoints[index];
if (evaluateCutPoint(rest, item)) {
if (debug)
cout << "Accepted: " << item << endl;
//Assign class number to the interval (cutpoint)
item.classNumber = classNumber++;
filtered.push_back(item);
first = false;
rest.start = item.end;
} else {
if (debug)
cout << "Rejected: " << item << endl;
if (index != size_t(cutPoints.size()) - 1) {
// Try to merge the rejected cutpoint with the next one
if (first) {
cutPoints[index + 1].fromValue = numeric_limits<float>::lowest();
cutPoints[index + 1].start = indices[0];
} else {
cutPoints[index + 1].fromValue = item.fromValue;
cutPoints[index + 1].start = item.start;
}
}
}
}
if (!first) {
filtered.back().toValue = numeric_limits<float>::max();
filtered.back().end = X.size() - 1;
} else {
filtered.push_back(rest);
}
cutPoints = filtered;
}
void CPPFImdlp::computeCutPointsProposal()
{
cutPoints_t cutPts;
cutPoint_t cutPoint;
float xPrev, xCur, xPivot;
int yPrev, yCur, yPivot;
size_t idx, numElements, start;
xCur = xPrev = X[indices[0]];
yCur = yPrev = y[indices[0]];
numElements = indices.size() - 1;
idx = start = 0;
bool firstCutPoint = true;
if (debug)
printf("*idx=%lu -> (-1, -1) Prev(%3.1f, %d) Elementos: %lu\n", idx, xCur, yCur, numElements);
while (idx < numElements) {
xPivot = xCur;
yPivot = yCur;
if (debug)
printf("<idx=%lu -> Prev(%3.1f, %d) Pivot(%3.1f, %d) Cur(%3.1f, %d) \n", idx, xPrev, yPrev, xPivot, yPivot, xCur, yCur);
// Read the same values and check class changes
do {
idx++;
xCur = X[indices[idx]];
yCur = y[indices[idx]];
if (yCur != yPivot && xCur == xPivot) {
yPivot = -1;
}
if (debug)
printf(">idx=%lu -> Prev(%3.1f, %d) Pivot(%3.1f, %d) Cur(%3.1f, %d) \n", idx, xPrev, yPrev, xPivot, yPivot, xCur, yCur);
}
while (idx < numElements && xCur == xPivot);
// Check if the class changed and there are more than 1 element
if ((idx - start > 1) && (yPivot == -1 || yPrev != yCur) && goodCut(start, idx, numElements + 1)) {
// Must we add the entropy criteria here?
// if (totalEntropy - (entropyLeft + entropyRight) > 0) { Accept cut point }
cutPoint.start = start;
cutPoint.end = idx;
start = idx;
cutPoint.fromValue = firstCutPoint ? numeric_limits<float>::lowest() : cutPts.back().toValue;
cutPoint.toValue = (xPrev + xCur) / 2;
cutPoint.classNumber = -1;
firstCutPoint = false;
if (debug) {
printf("Cutpoint idx=%lu Cur(%3.1f, %d) Prev(%3.1f, %d) Pivot(%3.1f, %d) = (%3.1g, %3.1g] \n", idx, xCur, yCur, xPrev, yPrev, xPivot, yPivot, cutPoint.fromValue, cutPoint.toValue);
}
cutPts.push_back(cutPoint);
}
yPrev = yPivot;
xPrev = xPivot;
}
if (idx == numElements) {
cutPoint.start = start;
cutPoint.end = numElements + 1;
cutPoint.fromValue = firstCutPoint ? numeric_limits<float>::lowest() : cutPts.back().toValue;
cutPoint.toValue = numeric_limits<float>::max();
cutPoint.classNumber = -1;
if (debug)
printf("Final Cutpoint idx=%lu Cur(%3.1f, %d) Prev(%3.1f, %d) Pivot(%3.1f, %d) = (%3.1g, %3.1g] \n", idx, xCur, yCur, xPrev, yPrev, xPivot, yPivot, cutPoint.fromValue, cutPoint.toValue);
cutPts.push_back(cutPoint);
}
if (debug) {
cout << "Entropy of the dataset: " << Metrics::entropy(y, indices, 0, numElements + 1, numClasses) << endl;
for (auto cutPt : cutPts)
cout << "Entropy: " << Metrics::entropy(y, indices, cutPt.start, cutPt.end, numClasses) << " :Proposal: Cut point: " << cutPt;
}
cutPoints = cutPts;
}
void CPPFImdlp::computeCutPointsOriginal()
{
cutPoints_t cutPts;
cutPoint_t cutPoint;
float xPrev;
int yPrev;
bool first = true;
// idxPrev is the index of the init instance of the cutPoint
size_t index, idxPrev = 0, last, idx = indices[0];
xPrev = X[idx];
yPrev = y[idx];
last = indices.size() - 1;
for (index = 0; index < last; index++) {
idx = indices[index];
// Definition 2 Cut points are always on class boundaries &&
// there are more than 1 items in the interval
// if (entropy of interval) > (entropyLeft + entropyRight)) { Accept cut point } (goodCut)
if (y[idx] != yPrev && xPrev < X[idx] && idxPrev != index - 1 && goodCut(idxPrev, idx, last + 1)) {
// Must we add the entropy criteria here?
if (first) {
first = false;
cutPoint.fromValue = numeric_limits<float>::lowest();
} else {
cutPoint.fromValue = cutPts.back().toValue;
}
cutPoint.start = idxPrev;
cutPoint.end = index;
cutPoint.classNumber = -1;
cutPoint.toValue = round(divider * (X[idx] + xPrev) / 2) / divider;
idxPrev = index;
cutPts.push_back(cutPoint);
}
xPrev = X[idx];
yPrev = y[idx];
}
if (first) {
cutPoint.start = 0;
cutPoint.classNumber = -1;
cutPoint.fromValue = numeric_limits<float>::lowest();
cutPoint.toValue = numeric_limits<float>::max();
cutPts.push_back(cutPoint);
} else
cutPts.back().toValue = numeric_limits<float>::max();
cutPts.back().end = X.size();
if (debug) {
cout << "Entropy of the dataset: " << Metrics::entropy(y, indices, 0, indices.size(), numClasses) << endl;
for (auto cutPt : cutPts)
cout << "Entropy: " << Metrics::entropy(y, indices, cutPt.start, cutPt.end, numClasses) << ": Original: Cut point: " << cutPt;
}
cutPoints = cutPts;
}
bool CPPFImdlp::goodCut(size_t start, size_t cut, size_t end)
{
/*
Meter las entropías en una matríz cuadrada dispersa (samples, samples) M[start, end] iniciada a -1 y si no se ha calculado calcularla y almacenarla
*/
float entropyLeft = Metrics::entropy(y, indices, start, cut, numClasses);
float entropyRight = Metrics::entropy(y, indices, cut, end, numClasses);
float entropyInterval = Metrics::entropy(y, indices, start, end, numClasses);
if (debug)
printf("Entropy L, R, T: L(%5.3g) + R(%5.3g) - T(%5.3g) \t", entropyLeft, entropyRight, entropyInterval);
//return (entropyInterval - (entropyLeft + entropyRight) > 0);
return true;
// Remove duplicates and sort
cutPoints_t output(cutPoints.size());
set<precision_t> s;
unsigned size = cutPoints.size();
for (unsigned i = 0; i < size; i++)
s.insert(cutPoints[i]);
output.assign(s.begin(), s.end());
sort(output.begin(), output.end());
return output;
}
// Argsort from https://stackoverflow.com/questions/1577475/c-sorting-and-keeping-track-of-indexes
indices_t CPPFImdlp::sortIndices(samples& X_)
@@ -275,12 +105,8 @@ namespace mdlp {
indices_t idx(X_.size());
iota(idx.begin(), idx.end(), 0);
for (size_t i = 0; i < X_.size(); i++)
stable_sort(idx.begin(), idx.end(), [&X_](size_t i1, size_t i2)
sort(idx.begin(), idx.end(), [&X_](size_t i1, size_t i2)
{ return X_[i1] < X_[i2]; });
return idx;
}
void CPPFImdlp::setCutPoints(cutPoints_t cutPoints_)
{
cutPoints = cutPoints_;
}
}

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@@ -1,39 +1,30 @@
#ifndef CPPFIMDLP_H
#define CPPFIMDLP_H
#include "typesFImdlp.h"
#include "Metrics.h"
#include <utility>
namespace mdlp {
class CPPFImdlp {
protected:
bool proposal; // proposed algorithm or original algorithm
int precision;
bool debug;
float divider;
indices_t indices; // sorted indices to use with X and y
samples X;
labels y;
labels xDiscretized;
int numClasses;
Metrics metrics;
cutPoints_t cutPoints;
void setCutPoints(cutPoints_t);
static indices_t sortIndices(samples&);
void computeCutPointsOriginal();
void computeCutPointsProposal();
bool evaluateCutPoint(cutPoint_t, cutPoint_t);
void filterCutPoints();
bool goodCut(size_t, size_t, size_t); // if the cut candidate reduces entropy
void computeCutPoints(size_t, size_t);
long int getCandidate(size_t, size_t);
bool mdlp(size_t, size_t, size_t);
public:
CPPFImdlp();
CPPFImdlp(bool, int, bool debug = false);
CPPFImdlp(bool, bool debug = false);
~CPPFImdlp();
samples getCutPoints();
indices_t getIndices();
labels getDiscretizedValues();
void debugPoints(samples&, labels&);
CPPFImdlp& fit(samples&, labels&);
labels transform(samples&);
samples getCutPoints();
};
}
#endif

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@@ -1,46 +1,63 @@
#include "Metrics.h"
#include <set>
#include <iostream>
using namespace std;
namespace mdlp {
Metrics::Metrics()
= default;
int Metrics::numClasses(labels& y, indices_t indices, size_t start, size_t end)
Metrics::Metrics(labels& y_, indices_t& indices_): y(y_), indices(indices_), numClasses(computeNumClasses(0, indices.size())), entropyCache(cacheEnt_t()), igCache(cacheIg_t())
{
std::set<int> numClasses;
for (auto i = start; i < end; ++i) {
numClasses.insert(y[indices[i]]);
}
return numClasses.size();
}
float Metrics::entropy(labels& y, indices_t& indices, size_t start, size_t end, int nClasses)
int Metrics::computeNumClasses(size_t start, size_t end)
{
float entropy = 0;
set<int> nClasses;
for (auto i = start; i < end; ++i) {
nClasses.insert(y[indices[i]]);
}
return nClasses.size();
}
void Metrics::setData(labels& y_, indices_t& indices_)
{
indices = indices_;
y = y_;
numClasses = computeNumClasses(0, indices.size());
}
precision_t Metrics::entropy(size_t start, size_t end)
{
precision_t p, ventropy = 0;
int nElements = 0;
labels counts(nClasses + 1, 0);
labels counts(numClasses + 1, 0);
if (end - start < 2)
return 0;
if (entropyCache.find(make_tuple(start, end)) != entropyCache.end()) {
return entropyCache[make_tuple(start, end)];
}
for (auto i = &indices[start]; i != &indices[end]; ++i) {
counts[y[*i]]++;
nElements++;
}
for (auto count : counts) {
if (count > 0) {
float p = (float)count / nElements;
entropy -= p * log2(p);
p = (precision_t)count / nElements;
ventropy -= p * log2(p);
}
}
return entropy < 0 ? 0 : entropy;
entropyCache[make_tuple(start, end)] = ventropy;
return ventropy;
}
float Metrics::informationGain(labels& y, indices_t& indices, size_t start, size_t end, size_t cutPoint, int nClasses)
precision_t Metrics::informationGain(size_t start, size_t cut, size_t end)
{
float iGain;
float entropy, entropyLeft, entropyRight;
int nClassesLeft, nClassesRight;
int nElementsLeft = cutPoint - start, nElementsRight = end - cutPoint;
precision_t iGain;
precision_t entropyInterval, entropyLeft, entropyRight;
int nElementsLeft = cut - start, nElementsRight = end - cut;
int nElements = end - start;
nClassesLeft = Metrics::numClasses(y, indices, start, cutPoint);
nClassesRight = Metrics::numClasses(y, indices, cutPoint, end);
entropy = Metrics::entropy(y, indices, start, end, nClasses);
entropyLeft = Metrics::entropy(y, indices, start, cutPoint, nClassesLeft);
entropyRight = Metrics::entropy(y, indices, cutPoint, end, nClassesRight);
iGain = entropy - ((float)nElementsLeft * entropyLeft + (float)nElementsRight * entropyRight) / nElements;
if (igCache.find(make_tuple(start, cut, end)) != igCache.end()) {
cout << "**********Cache IG hit for " << start << " " << end << endl;
return igCache[make_tuple(start, cut, end)];
}
entropyInterval = entropy(start, end);
entropyLeft = entropy(start, cut);
entropyRight = entropy(cut, end);
iGain = entropyInterval - ((precision_t)nElementsLeft * entropyLeft + (precision_t)nElementsRight * entropyRight) / nElements;
igCache[make_tuple(start, cut, end)] = iGain;
return iGain;
}

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@@ -1,14 +1,21 @@
#ifndef METRICS_H
#define METRICS_H
#ifndef CCMETRICS_H
#define CCMETRICS_H
#include "typesFImdlp.h"
#include <cmath>
namespace mdlp {
class Metrics {
protected:
labels& y;
indices_t& indices;
int numClasses;
cacheEnt_t entropyCache;
cacheIg_t igCache;
public:
Metrics();
static int numClasses(labels&, indices_t, size_t, size_t);
static float entropy(labels&, indices_t&, size_t, size_t, int);
static float informationGain(labels&, indices_t&, size_t, size_t, size_t, int);
Metrics(labels&, indices_t&);
void setData(labels&, indices_t&);
int computeNumClasses(size_t, size_t);
precision_t entropy(size_t, size_t);
precision_t informationGain(size_t, size_t, size_t);
};
}
#endif

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@@ -1,110 +0,0 @@
#include "ccFImdlp.h"
#include <numeric>
#include <iostream>
#include <algorithm>
#include <set>
#include "ccMetrics.h"
namespace mdlp {
CPPFImdlp::CPPFImdlp(): proposal(true), precision(6), debug(false), divider(pow(10, precision)), indices(indices_t()), y(labels()), metrics(Metrics(y, indices))
{
}
CPPFImdlp::CPPFImdlp(bool proposal, int precision, bool debug): proposal(proposal), precision(precision), debug(debug), divider(pow(10, precision)), indices(indices_t()), y(labels()), metrics(Metrics(y, indices))
{
}
CPPFImdlp::~CPPFImdlp()
= default;
CPPFImdlp& CPPFImdlp::fitx(samples& X_, labels& y_)
{
X = X_;
y = y_;
if (X.size() != y.size()) {
throw invalid_argument("X and y must have the same size");
}
if (X.size() == 0 || y.size() == 0) {
throw invalid_argument("X and y must have at least one element");
}
indices = sortIndices(X_);
metrics.setData(y, indices);
computeCutPoints(0, X.size());
return *this;
}
void CPPFImdlp::computeCutPoints(size_t start, size_t end)
{
int cut;
if (end - start < 2)
return;
cut = getCandidate(start, end);
if (cut == -1 || !mdlp(start, cut, end)) {
// cut.value == -1 means that there is no candidate in the interval
// that enhances the information gain
if (start != 0)
xCutPoints.push_back(xcutPoint_t({ start, (X[indices[start]] + X[indices[start - 1]]) / 2 }));
if (end != X.size())
xCutPoints.push_back(xcutPoint_t({ end, (X[indices[end]] + X[indices[end - 1]]) / 2 }));
return;
}
computeCutPoints(start, cut);
computeCutPoints(cut, end);
}
long int CPPFImdlp::getCandidate(size_t start, size_t end)
{
long int candidate = -1, elements = end - start;
float entropy_left, entropy_right, minEntropy = numeric_limits<float>::max();
for (auto idx = start + 1; idx < end; idx++) {
// Cutpoints are always on boudndaries
if (y[indices[idx]] == y[indices[idx - 1]])
continue;
entropy_left = float(idx - start) / elements * metrics.entropy(start, idx);
entropy_right = float(end - idx) / elements * metrics.entropy(idx, end);
if (entropy_left + entropy_right < minEntropy) {
minEntropy = entropy_left + entropy_right;
candidate = idx;
}
}
return candidate;
}
bool CPPFImdlp::mdlp(size_t start, size_t cut, size_t end)
{
int k, k1, k2;
float ig, delta;
float ent, ent1, ent2;
auto N = float(end - start);
if (N < 2) {
return false;
}
k = metrics.computeNumClasses(start, end);
k1 = metrics.computeNumClasses(start, cut);
k2 = metrics.computeNumClasses(cut, end);
ent = metrics.entropy(start, end);
ent1 = metrics.entropy(start, cut);
ent2 = metrics.entropy(cut, end);
ig = metrics.informationGain(start, cut, end);
delta = log2(pow(3, float(k)) - 2) - (float(k) * ent - float(k1) * ent1 - float(k2) * ent2);
float term = 1 / N * (log2(N - 1) + delta);
return ig > term;
}
samples CPPFImdlp::getCutPointsx()
{
// Remove duplicates and sort
samples output(xCutPoints.size());
set<float> s;
unsigned size = xCutPoints.size();
for (unsigned i = 0; i < size; i++)
s.insert(xCutPoints[i].value);
output.assign(s.begin(), s.end());
sort(output.begin(), output.end());
return output;
}
// Argsort from https://stackoverflow.com/questions/1577475/c-sorting-and-keeping-track-of-indexes
indices_t CPPFImdlp::sortIndices(samples& X_)
{
indices_t idx(X_.size());
iota(idx.begin(), idx.end(), 0);
for (size_t i = 0; i < X_.size(); i++)
sort(idx.begin(), idx.end(), [&X_](size_t i1, size_t i2)
{ return X_[i1] < X_[i2]; });
return idx;
}
}

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@@ -1,32 +0,0 @@
#ifndef CCFIMDLP_H
#define CCFIMDLP_H
#include "typesFImdlp.h"
#include "ccMetrics.h"
#include <utility>
namespace mdlp {
class CPPFImdlp {
protected:
bool proposal; // proposed algorithm or original algorithm
int precision;
bool debug;
float divider;
indices_t indices; // sorted indices to use with X and y
samples X;
labels y;
Metrics metrics;
xcutPoints_t xCutPoints;
static indices_t sortIndices(samples&);
void computeCutPoints(size_t, size_t);
long int getCandidate(size_t, size_t);
bool mdlp(size_t, size_t, size_t);
public:
CPPFImdlp();
CPPFImdlp(bool, int, bool debug = false);
~CPPFImdlp();
CPPFImdlp& fitx(samples&, labels&);
samples getCutPointsx();
};
}
#endif

View File

@@ -1,74 +0,0 @@
#include "ccMetrics.h"
#include <set>
#include <iostream>
using namespace std;
namespace mdlp {
Metrics::Metrics(labels& y_, indices_t& indices_): y(y_), indices(indices_), numClasses(computeNumClasses(0, indices.size())), entropyCache(cacheEnt_t()), igCache(cacheIg_t())
{
}
int Metrics::computeNumClasses(size_t start, size_t end)
{
set<int> nClasses;
for (auto i = start; i < end; ++i) {
nClasses.insert(y[indices[i]]);
}
return nClasses.size();
}
void Metrics::setData(labels& y_, indices_t& indices_)
{
indices = indices_;
y = y_;
numClasses = computeNumClasses(0, indices.size());
}
float Metrics::entropy(size_t start, size_t end)
{
float p, ventropy = 0;
int nElements = 0;
labels counts(numClasses + 1, 0);
if (end - start < 2)
return 0;
if (entropyCache.find(make_tuple(start, end)) != entropyCache.end()) {
return entropyCache[make_tuple(start, end)];
}
for (auto i = &indices[start]; i != &indices[end]; ++i) {
counts[y[*i]]++;
nElements++;
}
for (auto count : counts) {
if (count > 0) {
p = (float)count / nElements;
ventropy -= p * log2(p);
}
}
entropyCache[make_tuple(start, end)] = ventropy;
return ventropy;
}
float Metrics::informationGain(size_t start, size_t cut, size_t end)
{
float iGain;
float entropyInterval, entropyLeft, entropyRight;
int nElementsLeft = cut - start, nElementsRight = end - cut;
int nElements = end - start;
if (igCache.find(make_tuple(start, cut, end)) != igCache.end()) {
cout << "**********Cache IG hit for " << start << " " << end << endl;
return igCache[make_tuple(start, cut, end)];
}
entropyInterval = entropy(start, end);
entropyLeft = entropy(start, cut);
entropyRight = entropy(cut, end);
iGain = entropyInterval - ((float)nElementsLeft * entropyLeft + (float)nElementsRight * entropyRight) / nElements;
igCache[make_tuple(start, cut, end)] = iGain;
return iGain;
}
}
/*
cache_t entropyCache;
std::map<std::tuple<int, int>, double> c;
// Set the value at index (3, 5) to 7.8.
c[std::make_tuple(3, 5)] = 7.8;
// Print the value at index (3, 5).
std::cout << c[std::make_tuple(3, 5)] << std::endl;
*/

View File

@@ -1,21 +0,0 @@
#ifndef CCMETRICS_H
#define CCMETRICS_H
#include "typesFImdlp.h"
#include <cmath>
namespace mdlp {
class Metrics {
protected:
labels& y;
indices_t& indices;
int numClasses;
cacheEnt_t entropyCache;
cacheIg_t igCache;
public:
Metrics(labels&, indices_t&);
void setData(labels&, indices_t&);
int computeNumClasses(size_t, size_t);
float entropy(size_t, size_t);
float informationGain(size_t, size_t, size_t);
};
}
#endif

View File

@@ -3,16 +3,13 @@
from libcpp.vector cimport vector
from libcpp cimport bool
cdef extern from "ccFImdlp.h" namespace "mdlp":
cdef struct CutPointBody:
size_t start, end;
int classNumber;
float fromValue, toValue;
cdef extern from "CPPFImdlp.h" namespace "mdlp":
ctypedef float precision_t
cdef cppclass CPPFImdlp:
CPPFImdlp() except +
CPPFImdlp(bool, int, bool) except +
CPPFImdlp& fitx(vector[float]&, vector[int]&)
vector[float] getCutPointsx()
CPPFImdlp(bool, bool) except +
CPPFImdlp& fit(vector[precision_t]&, vector[int]&)
vector[precision_t] getCutPoints()
class PcutPoint_t:
@@ -24,14 +21,14 @@ class PcutPoint_t:
cdef class CFImdlp:
cdef CPPFImdlp *thisptr
def __cinit__(self, precision=6, debug=False, proposal=True):
def __cinit__(self, debug=False, proposal=True):
# Proposal or original algorithm
self.thisptr = new CPPFImdlp(proposal, precision, debug)
self.thisptr = new CPPFImdlp(proposal, debug)
def __dealloc__(self):
del self.thisptr
def fit(self, X, y):
self.thisptr.fitx(X, y)
self.thisptr.fit(X, y)
return self
def get_cut_points(self):
return self.thisptr.getCutPointsx()
return self.thisptr.getCutPoints()

View File

@@ -1,36 +0,0 @@
#include <vector>
using namespace std;
struct CutPointBody {
size_t start, end; // indices of the sorted vector
int classNumber; // class assigned to the cut point
float fromValue, toValue;
};
typedef CutPointBody cutPoint_t;
typedef vector<float> samples;
typedef vector<int> labels;
typedef vector<size_t> indices_t;
typedef vector<cutPoint_t> cutPoints_t;
//typedef std::map<std::tuple<int, int>, float> cache_t;
struct cutPointStruct {
size_t index;
float value;
};
typedef cutPointStruct xcutPoint_t;
typedef vector<xcutPoint_t> xcutPoints_t;
class Metrics {
private:
labels& y;
indices_t& indices;
int numClasses;
public:
Metrics(labels&, indices_t&);
int computeNumClasses(size_t, size_t);
float entropy(size_t, size_t);
float informationGain(size_t, size_t, size_t);
};
Metrics::Metrics(labels& y_, indices_t& indices_) : y(y_), indices(indices_)
{
numClasses = computeNumClasses(0, indices.size());
}

Binary file not shown.

View File

@@ -1,52 +0,0 @@
#include "CPPFImdlp.h"
#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <sstream>
using namespace std;
using namespace mdlp;
int main()
{
ifstream fin("kdd_JapaneseVowels.arff");
if (!fin.is_open()) {
cout << "Error opening file" << endl;
return 1;
}
int count = 0;
// Read the Data from the file
// as String Vector
size_t col;
vector<string> row;
string line, word;
vector<vector<float>> dataset = vector<vector<float>>(15, vector<float>());
while (getline(fin, line)) {
if (count++ > 215) {
stringstream ss(line);
col = 0;
while (getline(ss, word, ',')) {
col = col % 15;
dataset[col].push_back(stof(word));
cout << col << "-" << word << " ";
col++;
}
cout << endl;
}
}
labels y = labels(dataset[0].begin(), dataset[0].end());
cout << "Column 0 (y): " << y.size() << endl;
for (auto item : y) {
cout << item << " ";
}
CPPFImdlp test = CPPFImdlp(false, 6, true);
test.fit(dataset[3], y);
cout << "Cut points: " << test.getCutPoints().size() << endl;
for (auto item : test.getCutPoints()) {
cout << item << " ";
}
fin.close();
return 0;
}

View File

@@ -1,6 +1,5 @@
import numpy as np
from .cppfimdlp import CFImdlp
from .pyfimdlp import PyFImdlp
from sklearn.base import BaseEstimator, TransformerMixin
from sklearn.utils.multiclass import unique_labels
from sklearn.utils.validation import check_X_y, check_array, check_is_fitted

View File

@@ -1,479 +0,0 @@
import numpy as np
from math import log2
from types import SimpleNamespace
class PyFImdlp:
def __init__(self, proposal=True, debug=False):
self.proposal = proposal
self.n_features_ = None
self.X_ = None
self.y_ = None
self.debug = debug
self.features_ = None
self.cut_points_ = []
self.entropy_cache = {}
self.information_gain_cache = {}
def fit(self, X, y):
self.n_features_ = len(X)
self.indices_ = np.argsort(X)
self.use_indices = False
X = [
4.3,
4.4,
4.4,
4.4,
4.5,
4.6,
4.6,
4.6,
4.6,
4.7,
4.7,
4.8,
4.8,
4.8,
4.8,
4.8,
4.9,
4.9,
4.9,
4.9,
4.9,
4.9,
5,
5,
5,
5,
5,
5,
5,
5,
5,
5,
5.1,
5.1,
5.1,
5.1,
5.1,
5.1,
5.1,
5.1,
5.1,
5.2,
5.2,
5.2,
5.2,
5.3,
5.4,
5.4,
5.4,
5.4,
5.4,
5.4,
5.5,
5.5,
5.5,
5.5,
5.5,
5.5,
5.5,
5.6,
5.6,
5.6,
5.6,
5.6,
5.6,
5.7,
5.7,
5.7,
5.7,
5.7,
5.7,
5.7,
5.7,
5.8,
5.8,
5.8,
5.8,
5.8,
5.8,
5.8,
5.9,
5.9,
5.9,
6,
6,
6,
6,
6,
6,
6.1,
6.1,
6.1,
6.1,
6.1,
6.1,
6.2,
6.2,
6.2,
6.2,
6.3,
6.3,
6.3,
6.3,
6.3,
6.3,
6.3,
6.3,
6.3,
6.4,
6.4,
6.4,
6.4,
6.4,
6.4,
6.4,
6.5,
6.5,
6.5,
6.5,
6.5,
6.6,
6.6,
6.7,
6.7,
6.7,
6.7,
6.7,
6.7,
6.7,
6.7,
6.8,
6.8,
6.8,
6.9,
6.9,
6.9,
6.9,
7,
7.1,
7.2,
7.2,
7.2,
7.3,
7.4,
7.6,
7.7,
7.7,
7.7,
7.7,
7.9,
]
y = [
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
1,
2,
0,
0,
1,
0,
0,
0,
0,
1,
0,
0,
0,
1,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
1,
0,
0,
0,
0,
0,
0,
1,
0,
1,
1,
1,
1,
1,
0,
1,
1,
2,
1,
1,
1,
1,
1,
1,
0,
1,
2,
0,
1,
1,
2,
0,
1,
2,
1,
2,
2,
1,
1,
2,
1,
1,
1,
2,
1,
2,
2,
1,
1,
1,
1,
2,
2,
1,
1,
2,
2,
1,
2,
2,
1,
2,
1,
2,
2,
1,
2,
2,
2,
1,
2,
2,
2,
1,
2,
2,
1,
1,
2,
2,
2,
2,
2,
1,
1,
1,
2,
2,
1,
2,
1,
2,
2,
1,
2,
2,
2,
2,
2,
2,
2,
2,
2,
2,
2,
2,
]
# self.X_ = X[self.indices_] if not self.use_indices else X
# self.y_ = y[self.indices_] if not self.use_indices else y
self.X_ = X
self.y_ = y
self.compute_cut_points(0, len(y))
return self
def get_cut_points(self):
return sorted(list(set([cut.value for cut in self.cut_points_])))
def compute_cut_points(self, start, end):
# print((start, end))
cut = self.get_candidate(start, end)
if cut.value is None:
return
print("cut: ", cut.value, " index: ", cut.index)
if self.mdlp(cut, start, end):
print("¡Ding!", cut.value, cut.index)
self.cut_points_.append(cut)
self.compute_cut_points(start, cut.index)
self.compute_cut_points(cut.index, end)
def mdlp(self, cut, start, end):
N = end - start
k = self.num_classes(start, end)
k1 = self.num_classes(start, cut.index)
k2 = self.num_classes(cut.index, end)
ent = self.entropy(start, end)
ent1 = self.entropy(start, cut.index)
ent2 = self.entropy(cut.index, end)
ig = self.information_gain(start, cut.index, end)
delta = log2(pow(3, k) - 2, 2) - (
float(k) * ent - float(k1) * ent1 - float(k2) * ent2
)
term = 1 / N * (log2(N - 1, 2) + delta)
print("start: ", start, " cut: ", cut.index, " end: ", end)
print(
"k=",
k,
" k1=",
k1,
" k2=",
k2,
" ent=",
ent,
" ent1=",
ent1,
" ent2=",
ent2,
)
print("ig=", ig, " delta=", delta, " N ", N, " term ", term)
return ig > term
def num_classes(self, start, end):
n_classes = set()
for i in range(start, end):
n_classes.add(
self.y_[self.indices_[i]] if self.use_indices else self.y_[i]
)
return len(n_classes)
def get_candidate(self, start, end):
"""Return the best cutpoint candidate for the given range.
Parameters
----------
start : int
Start of the range.
end : int
End of the range.
Returns
-------
candidate : SimpleNamespace with attributes index and value
value == None if no candidate is found.
"""
candidate = SimpleNamespace()
candidate.value = None
minEntropy = float("inf")
for idx in range(start + 1, end):
condition = (
self.y_[self.indices_[idx]] == self.y_[self.indices_[idx - 1]]
if self.use_indices
else self.y_[idx] == self.y_[idx - 1]
)
if condition:
continue
entropy_left = self.entropy(start, idx)
entropy_right = self.entropy(idx, end)
entropy_cut = entropy_left + entropy_right
print(
"idx: ",
idx,
" entropy_left: ",
entropy_left,
" entropy_right : ",
entropy_right,
" -> ",
start,
" ",
end,
)
if entropy_cut < minEntropy:
minEntropy = entropy_cut
candidate.index = idx
if self.use_indices:
candidate.value = (
self.X_[self.indices_[idx]]
+ self.X_[self.indices_[idx - 1]]
) / 2
else:
candidate.value = (self.X_[idx] + self.X_[idx - 1]) / 2
return candidate
def entropy(self, start, end) -> float:
n_labels = end - start
if n_labels <= 1:
return 0
if (start, end) in self.entropy_cache:
return self.entropy_cache[(start, end)]
if self.use_indices:
counts = np.bincount(self.y_[self.indices_[start:end]])
else:
counts = np.bincount(self.y_[start:end])
proportions = counts / n_labels
n_classes = np.count_nonzero(proportions)
if n_classes <= 1:
return 0
entropy = 0.0
# Compute standard entropy.
for prop in proportions:
if prop != 0.0:
entropy -= prop * log2(prop, 2)
self.entropy_cache[(start, end)] = entropy
return entropy
def information_gain(self, start, cut, end):
if (start, cut, end) in self.information_gain_cache:
return self.information_gain_cache[(start, cut, end)]
labels = end - start
if labels == 0:
return 0.0
entropy = self.entropy(start, end)
card_left = cut - start
entropy_left = self.entropy(start, cut)
card_right = end - cut
entropy_right = self.entropy(cut, end)
result = (
entropy
- (card_left / labels) * entropy_left
- (card_right / labels) * entropy_right
)
self.information_gain_cache[(start, cut, end)] = result
return result

View File

@@ -34,7 +34,7 @@ namespace mdlp {
X = X_;
indices = indices_;
indices_t testSortedIndices = sortIndices(X);
float prev = X[testSortedIndices[0]];
precision_t prev = X[testSortedIndices[0]];
for (auto i = 0; i < X.size(); ++i) {
EXPECT_EQ(testSortedIndices[i], indices[i]);
EXPECT_LE(prev, X[testSortedIndices[i]]);
@@ -162,7 +162,7 @@ namespace mdlp {
fit(X, y);
computeCutPointsOriginal();
cutPoints_t expected;
vector<float> computed = getCutPoints();
vector<precision_t> computed = getCutPoints();
expected = {
{ 0, 4, -1, -3.4028234663852886e+38, 5.15 }, { 4, 6, -1, 5.15, 5.45 },
{ 6, 10, -1, 5.45, 3.4028234663852886e+38 }

View File

@@ -2,7 +2,7 @@
#include "../Metrics.h"
namespace mdlp {
float precision = 0.000001;
precision_t precision = 0.000001;
TEST(MetricTest, NumClasses)
{
labels y = { 1, 1, 1, 1, 1, 1, 1, 1, 2, 1 };

View File

@@ -0,0 +1,286 @@
#include "CPPFImdlp.h"
#include <numeric>
#include <iostream>
#include <algorithm>
#include "Metrics.h"
namespace mdlp {
ostream& operator << (ostream& os, const cutPoint_t& cut)
{
os << cut.classNumber << " -> (" << cut.start << ", " << cut.end <<
") - (" << cut.fromValue << ", " << cut.toValue << ") "
<< endl;
return os;
}
CPPFImdlp::CPPFImdlp(): proposal(true), precision(6), debug(false)
{
divider = pow(10, precision);
numClasses = 0;
}
CPPFImdlp::CPPFImdlp(bool proposal, int precision, bool debug): proposal(proposal), precision(precision), debug(debug)
{
divider = pow(10, precision);
numClasses = 0;
}
CPPFImdlp::~CPPFImdlp()
= default;
samples CPPFImdlp::getCutPoints()
{
samples output(cutPoints.size());
::transform(cutPoints.begin(), cutPoints.end(), output.begin(),
[](cutPoint_t cut) { return cut.toValue; });
return output;
}
labels CPPFImdlp::getDiscretizedValues()
{
return xDiscretized;
}
CPPFImdlp& CPPFImdlp::fit(samples& X_, labels& y_)
{
X = X_;
y = y_;
if (X.size() != y.size()) {
throw invalid_argument("X and y must have the same size");
}
if (X.size() == 0 || y.size() == 0) {
throw invalid_argument("X and y must have at least one element");
}
indices = sortIndices(X_);
xDiscretized = labels(X.size(), -1);
numClasses = Metrics::numClasses(y, indices, 0, X.size());
if (proposal) {
computeCutPointsProposal();
} else {
computeCutPointsOriginal();
}
filterCutPoints();
// Apply cut points to the input vector
for (auto cut : cutPoints) {
for (size_t i = cut.start; i < cut.end; i++) {
xDiscretized[indices[i]] = cut.classNumber;
}
}
return *this;
}
bool CPPFImdlp::evaluateCutPoint(cutPoint_t rest, cutPoint_t candidate)
{
int k, k1, k2;
precision_t ig, delta;
precision_t ent, ent1, ent2;
auto N = precision_t(rest.end - rest.start);
if (N < 2) {
return false;
}
k = Metrics::numClasses(y, indices, rest.start, rest.end);
k1 = Metrics::numClasses(y, indices, rest.start, candidate.end);
k2 = Metrics::numClasses(y, indices, candidate.end, rest.end);
ent = Metrics::entropy(y, indices, rest.start, rest.end, numClasses);
ent1 = Metrics::entropy(y, indices, rest.start, candidate.end, numClasses);
ent2 = Metrics::entropy(y, indices, candidate.end, rest.end, numClasses);
ig = Metrics::informationGain(y, indices, rest.start, rest.end, candidate.end, numClasses);
delta = log2(pow(3, precision_t(k)) - 2) - (precision_t(k) * ent - precision_t(k1) * ent1 - precision_t(k2) * ent2);
precision_t term = 1 / N * (log2(N - 1) + delta);
if (debug) {
cout << "Rest: " << rest;
cout << "Candidate: " << candidate;
cout << "k=" << k << " k1=" << k1 << " k2=" << k2 << " ent=" << ent << " ent1=" << ent1 << " ent2=" << ent2 << endl;
cout << "ig=" << ig << " delta=" << delta << " N " << N << " term " << term << endl;
}
return (ig > term);
}
void CPPFImdlp::filterCutPoints()
{
cutPoints_t filtered;
cutPoint_t rest, item;
int classNumber = 0;
rest.start = 0;
rest.end = X.size();
rest.fromValue = numeric_limits<precision_t>::lowest();
rest.toValue = numeric_limits<precision_t>::max();
rest.classNumber = classNumber;
bool first = true;
for (size_t index = 0; index < size_t(cutPoints.size()); index++) {
item = cutPoints[index];
if (evaluateCutPoint(rest, item)) {
if (debug)
cout << "Accepted: " << item << endl;
//Assign class number to the interval (cutpoint)
item.classNumber = classNumber++;
filtered.push_back(item);
first = false;
rest.start = item.end;
} else {
if (debug)
cout << "Rejected: " << item << endl;
if (index != size_t(cutPoints.size()) - 1) {
// Try to merge the rejected cutpoint with the next one
if (first) {
cutPoints[index + 1].fromValue = numeric_limits<precision_t>::lowest();
cutPoints[index + 1].start = indices[0];
} else {
cutPoints[index + 1].fromValue = item.fromValue;
cutPoints[index + 1].start = item.start;
}
}
}
}
if (!first) {
filtered.back().toValue = numeric_limits<precision_t>::max();
filtered.back().end = X.size() - 1;
} else {
filtered.push_back(rest);
}
cutPoints = filtered;
}
void CPPFImdlp::computeCutPointsProposal()
{
cutPoints_t cutPts;
cutPoint_t cutPoint;
precision_t xPrev, xCur, xPivot;
int yPrev, yCur, yPivot;
size_t idx, numElements, start;
xCur = xPrev = X[indices[0]];
yCur = yPrev = y[indices[0]];
numElements = indices.size() - 1;
idx = start = 0;
bool firstCutPoint = true;
if (debug)
printf("*idx=%lu -> (-1, -1) Prev(%3.1f, %d) Elementos: %lu\n", idx, xCur, yCur, numElements);
while (idx < numElements) {
xPivot = xCur;
yPivot = yCur;
if (debug)
printf("<idx=%lu -> Prev(%3.1f, %d) Pivot(%3.1f, %d) Cur(%3.1f, %d) \n", idx, xPrev, yPrev, xPivot, yPivot, xCur, yCur);
// Read the same values and check class changes
do {
idx++;
xCur = X[indices[idx]];
yCur = y[indices[idx]];
if (yCur != yPivot && xCur == xPivot) {
yPivot = -1;
}
if (debug)
printf(">idx=%lu -> Prev(%3.1f, %d) Pivot(%3.1f, %d) Cur(%3.1f, %d) \n", idx, xPrev, yPrev, xPivot, yPivot, xCur, yCur);
}
while (idx < numElements && xCur == xPivot);
// Check if the class changed and there are more than 1 element
if ((idx - start > 1) && (yPivot == -1 || yPrev != yCur) && goodCut(start, idx, numElements + 1)) {
// Must we add the entropy criteria here?
// if (totalEntropy - (entropyLeft + entropyRight) > 0) { Accept cut point }
cutPoint.start = start;
cutPoint.end = idx;
start = idx;
cutPoint.fromValue = firstCutPoint ? numeric_limits<precision_t>::lowest() : cutPts.back().toValue;
cutPoint.toValue = (xPrev + xCur) / 2;
cutPoint.classNumber = -1;
firstCutPoint = false;
if (debug) {
printf("Cutpoint idx=%lu Cur(%3.1f, %d) Prev(%3.1f, %d) Pivot(%3.1f, %d) = (%3.1g, %3.1g] \n", idx, xCur, yCur, xPrev, yPrev, xPivot, yPivot, cutPoint.fromValue, cutPoint.toValue);
}
cutPts.push_back(cutPoint);
}
yPrev = yPivot;
xPrev = xPivot;
}
if (idx == numElements) {
cutPoint.start = start;
cutPoint.end = numElements + 1;
cutPoint.fromValue = firstCutPoint ? numeric_limits<precision_t>::lowest() : cutPts.back().toValue;
cutPoint.toValue = numeric_limits<precision_t>::max();
cutPoint.classNumber = -1;
if (debug)
printf("Final Cutpoint idx=%lu Cur(%3.1f, %d) Prev(%3.1f, %d) Pivot(%3.1f, %d) = (%3.1g, %3.1g] \n", idx, xCur, yCur, xPrev, yPrev, xPivot, yPivot, cutPoint.fromValue, cutPoint.toValue);
cutPts.push_back(cutPoint);
}
if (debug) {
cout << "Entropy of the dataset: " << Metrics::entropy(y, indices, 0, numElements + 1, numClasses) << endl;
for (auto cutPt : cutPts)
cout << "Entropy: " << Metrics::entropy(y, indices, cutPt.start, cutPt.end, numClasses) << " :Proposal: Cut point: " << cutPt;
}
cutPoints = cutPts;
}
void CPPFImdlp::computeCutPointsOriginal()
{
cutPoints_t cutPts;
cutPoint_t cutPoint;
precision_t xPrev;
int yPrev;
bool first = true;
// idxPrev is the index of the init instance of the cutPoint
size_t index, idxPrev = 0, last, idx = indices[0];
xPrev = X[idx];
yPrev = y[idx];
last = indices.size() - 1;
for (index = 0; index < last; index++) {
idx = indices[index];
// Definition 2 Cut points are always on class boundaries &&
// there are more than 1 items in the interval
// if (entropy of interval) > (entropyLeft + entropyRight)) { Accept cut point } (goodCut)
if (y[idx] != yPrev && xPrev < X[idx] && idxPrev != index - 1 && goodCut(idxPrev, idx, last + 1)) {
// Must we add the entropy criteria here?
if (first) {
first = false;
cutPoint.fromValue = numeric_limits<precision_t>::lowest();
} else {
cutPoint.fromValue = cutPts.back().toValue;
}
cutPoint.start = idxPrev;
cutPoint.end = index;
cutPoint.classNumber = -1;
cutPoint.toValue = round(divider * (X[idx] + xPrev) / 2) / divider;
idxPrev = index;
cutPts.push_back(cutPoint);
}
xPrev = X[idx];
yPrev = y[idx];
}
if (first) {
cutPoint.start = 0;
cutPoint.classNumber = -1;
cutPoint.fromValue = numeric_limits<precision_t>::lowest();
cutPoint.toValue = numeric_limits<precision_t>::max();
cutPts.push_back(cutPoint);
} else
cutPts.back().toValue = numeric_limits<precision_t>::max();
cutPts.back().end = X.size();
if (debug) {
cout << "Entropy of the dataset: " << Metrics::entropy(y, indices, 0, indices.size(), numClasses) << endl;
for (auto cutPt : cutPts)
cout << "Entropy: " << Metrics::entropy(y, indices, cutPt.start, cutPt.end, numClasses) << ": Original: Cut point: " << cutPt;
}
cutPoints = cutPts;
}
bool CPPFImdlp::goodCut(size_t start, size_t cut, size_t end)
{
/*
Meter las entropías en una matríz cuadrada dispersa (samples, samples) M[start, end] iniciada a -1 y si no se ha calculado calcularla y almacenarla
*/
precision_t entropyLeft = Metrics::entropy(y, indices, start, cut, numClasses);
precision_t entropyRight = Metrics::entropy(y, indices, cut, end, numClasses);
precision_t entropyInterval = Metrics::entropy(y, indices, start, end, numClasses);
if (debug)
printf("Entropy L, R, T: L(%5.3g) + R(%5.3g) - T(%5.3g) \t", entropyLeft, entropyRight, entropyInterval);
//return (entropyInterval - (entropyLeft + entropyRight) > 0);
return true;
}
// Argsort from https://stackoverflow.com/questions/1577475/c-sorting-and-keeping-track-of-indexes
indices_t CPPFImdlp::sortIndices(samples& X_)
{
indices_t idx(X_.size());
iota(idx.begin(), idx.end(), 0);
for (size_t i = 0; i < X_.size(); i++)
stable_sort(idx.begin(), idx.end(), [&X_](size_t i1, size_t i2)
{ return X_[i1] < X_[i2]; });
return idx;
}
void CPPFImdlp::setCutPoints(cutPoints_t cutPoints_)
{
cutPoints = cutPoints_;
}
}

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@@ -0,0 +1,39 @@
#ifndef CPPFIMDLP_H
#define CPPFIMDLP_H
#include "typesFImdlp.h"
#include <utility>
namespace mdlp {
class CPPFImdlp {
protected:
bool proposal; // proposed algorithm or original algorithm
int precision;
bool debug;
precision_t divider;
indices_t indices; // sorted indices to use with X and y
samples X;
labels y;
labels xDiscretized;
int numClasses;
cutPoints_t cutPoints;
void setCutPoints(cutPoints_t);
static indices_t sortIndices(samples&);
void computeCutPointsOriginal();
void computeCutPointsProposal();
bool evaluateCutPoint(cutPoint_t, cutPoint_t);
void filterCutPoints();
bool goodCut(size_t, size_t, size_t); // if the cut candidate reduces entropy
public:
CPPFImdlp();
CPPFImdlp(bool, int, bool debug = false);
~CPPFImdlp();
samples getCutPoints();
indices_t getIndices();
labels getDiscretizedValues();
void debugPoints(samples&, labels&);
CPPFImdlp& fit(samples&, labels&);
labels transform(samples&);
};
}
#endif

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@@ -0,0 +1,47 @@
#include "Metrics.h"
#include <set>
namespace mdlp {
Metrics::Metrics()
= default;
int Metrics::numClasses(labels& y, indices_t indices, size_t start, size_t end)
{
std::set<int> numClasses;
for (auto i = start; i < end; ++i) {
numClasses.insert(y[indices[i]]);
}
return numClasses.size();
}
precision_t Metrics::entropy(labels& y, indices_t& indices, size_t start, size_t end, int nClasses)
{
precision_t entropy = 0;
int nElements = 0;
labels counts(nClasses + 1, 0);
for (auto i = &indices[start]; i != &indices[end]; ++i) {
counts[y[*i]]++;
nElements++;
}
for (auto count : counts) {
if (count > 0) {
precision_t p = (precision_t)count / nElements;
entropy -= p * log2(p);
}
}
return entropy < 0 ? 0 : entropy;
}
precision_t Metrics::informationGain(labels& y, indices_t& indices, size_t start, size_t end, size_t cutPoint, int nClasses)
{
precision_t iGain;
precision_t entropy, entropyLeft, entropyRight;
int nClassesLeft, nClassesRight;
int nElementsLeft = cutPoint - start, nElementsRight = end - cutPoint;
int nElements = end - start;
nClassesLeft = Metrics::numClasses(y, indices, start, cutPoint);
nClassesRight = Metrics::numClasses(y, indices, cutPoint, end);
entropy = Metrics::entropy(y, indices, start, end, nClasses);
entropyLeft = Metrics::entropy(y, indices, start, cutPoint, nClassesLeft);
entropyRight = Metrics::entropy(y, indices, cutPoint, end, nClassesRight);
iGain = entropy - ((precision_t)nElementsLeft * entropyLeft + (precision_t)nElementsRight * entropyRight) / nElements;
return iGain;
}
}

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@@ -0,0 +1,14 @@
#ifndef METRICS_H
#define METRICS_H
#include "typesFImdlp.h"
#include <cmath>
namespace mdlp {
class Metrics {
public:
Metrics();
static int numClasses(labels&, indices_t, size_t, size_t);
static precision_t entropy(labels&, indices_t&, size_t, size_t, int);
static precision_t informationGain(labels&, indices_t&, size_t, size_t, size_t, int);
};
}
#endif

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@@ -5,21 +5,12 @@
using namespace std;
namespace mdlp {
struct CutPointBody {
size_t start, end; // indices of the sorted vector
};
typedef CutPointBody cutPoint_t;
typedef vector<float> samples;
typedef float precision_t;
typedef vector<precision_t> samples;
typedef vector<int> labels;
typedef vector<size_t> indices_t;
typedef vector<cutPoint_t> cutPoints_t;
typedef map<tuple<int, int>, float> cacheEnt_t;
typedef map<tuple<int, int, int>, float> cacheIg_t;
struct cutPointStruct {
size_t index;
float value;
};
typedef cutPointStruct xcutPoint_t;
typedef vector<xcutPoint_t> xcutPoints_t;
typedef vector<precision_t> cutPoints_t;
typedef map<tuple<int, int>, precision_t> cacheEnt_t;
typedef map<tuple<int, int, int>, precision_t> cacheIg_t;
}
#endif

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@@ -13,7 +13,7 @@ namespace FImdlp {
int n = X.size();
for (i = 1; i < n; i++) {
if (X.at(i) != ant) {
cutPts.push_back(float(X.at(i) + ant) / 2);
cutPts.push_back(precision_t(X.at(i) + ant) / 2);
ant = X.at(i);
}
}

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@@ -5,7 +5,7 @@ from libcpp.vector cimport vector
cdef extern from "FImdlp.h" namespace "FImdlp":
cdef cppclass FImdlp:
FImdlp() except +
vector[float] cutPoints(vector[int]&, vector[int]&)
vector[precision_t] cutPoints(vector[int]&, vector[int]&)
cdef class CFImdlp:
cdef FImdlp *thisptr

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@@ -12,10 +12,8 @@ setup(
name="cppfimdlp",
sources=[
"fimdlp/cfimdlp.pyx",
# "fimdlp/CPPFImdlp.cpp",
# "fimdlp/Metrics.cpp",
"fimdlp/ccMetrics.cc",
"fimdlp/ccFImdlp.cc",
"fimdlp/CPPFImdlp.cpp",
"fimdlp/Metrics.cpp",
],
language="c++",
include_dirs=["fimdlp"],