pmlpp/mlpp/cost/cost.cpp
2023-01-24 18:12:23 +01:00

422 lines
15 KiB
C++

//
// Reg.cpp
//
// Created by Marc Melikyan on 1/16/21.
//
#include <iostream>
#include <cmath>
#include "cost.hpp"
#include "../lin_alg/lin_alg.h"
#include "../regularization/reg.h"
namespace MLPP{
double Cost::MSE(std::vector <double> y_hat, std::vector<double> y){
double sum = 0;
for(int i = 0; i < y_hat.size(); i++){
sum += (y_hat[i] - y[i]) * (y_hat[i] - y[i]);
}
return sum / 2 * y_hat.size();
}
double Cost::MSE(std::vector<std::vector<double>> y_hat, std::vector<std::vector<double>> y){
double sum = 0;
for(int i = 0; i < y_hat.size(); i++){
for(int j = 0; j < y_hat[i].size(); j++){
sum += (y_hat[i][j] - y[i][j]) * (y_hat[i][j] - y[i][j]);
}
}
return sum / 2 * y_hat.size();
}
std::vector<double> Cost::MSEDeriv(std::vector <double> y_hat, std::vector<double> y){
LinAlg alg;
return alg.subtraction(y_hat, y);
}
std::vector<std::vector<double>> Cost::MSEDeriv(std::vector<std::vector<double>> y_hat, std::vector<std::vector<double>> y){
LinAlg alg;
return alg.subtraction(y_hat, y);
}
double Cost::RMSE(std::vector <double> y_hat, std::vector<double> y){
double sum = 0;
for(int i = 0; i < y_hat.size(); i++){
sum += (y_hat[i] - y[i]) * (y_hat[i] - y[i]);
}
return sqrt(sum / y_hat.size());
}
double Cost::RMSE(std::vector<std::vector<double>> y_hat, std::vector<std::vector<double>> y){
double sum = 0;
for(int i = 0; i < y_hat.size(); i++){
for(int j = 0; j < y_hat[i].size(); j++){
sum += (y_hat[i][j] - y[i][j]) * (y_hat[i][j] - y[i][j]);
}
}
return sqrt(sum / y_hat.size());
}
std::vector<double> Cost::RMSEDeriv(std::vector <double> y_hat, std::vector<double> y){
LinAlg alg;
return alg.scalarMultiply(1/(2*sqrt(MSE(y_hat, y))), MSEDeriv(y_hat, y));
}
std::vector<std::vector<double>> Cost::RMSEDeriv(std::vector<std::vector<double>> y_hat, std::vector<std::vector<double>> y){
LinAlg alg;
return alg.scalarMultiply(1/(2/sqrt(MSE(y_hat, y))), MSEDeriv(y_hat, y));
}
double Cost::MAE(std::vector <double> y_hat, std::vector<double> y){
double sum = 0;
for(int i = 0; i < y_hat.size(); i++){
sum += abs((y_hat[i] - y[i]));
}
return sum / y_hat.size();
}
double Cost::MAE(std::vector<std::vector<double>> y_hat, std::vector<std::vector<double>> y){
double sum = 0;
for(int i = 0; i < y_hat.size(); i++){
for(int j = 0; j < y_hat[i].size(); j++){
sum += abs((y_hat[i][j] - y[i][j]));
}
}
return sum / y_hat.size();
}
std::vector<double> Cost::MAEDeriv(std::vector <double> y_hat, std::vector <double> y){
std::vector<double> deriv;
deriv.resize(y_hat.size());
for(int i = 0; i < deriv.size(); i++){
if(y_hat[i] < 0){
deriv[i] = -1;
}
else if(y_hat[i] == 0){
deriv[i] = 0;
}
else{
deriv[i] = 1;
}
}
return deriv;
}
std::vector<std::vector<double>> Cost::MAEDeriv(std::vector<std::vector<double>> y_hat, std::vector<std::vector<double>> y){
std::vector<std::vector<double>> deriv;
deriv.resize(y_hat.size());
for(int i = 0; i < deriv.size(); i++){
deriv.resize(y_hat[i].size());
}
for(int i = 0; i < deriv.size(); i++){
for(int j = 0; j < deriv[i].size(); j++){
if(y_hat[i][j] < 0){
deriv[i][j] = -1;
}
else if(y_hat[i][j] == 0){
deriv[i][j] = 0;
}
else{
deriv[i][j] = 1;
}
}
}
return deriv;
}
double Cost::MBE(std::vector <double> y_hat, std::vector<double> y){
double sum = 0;
for(int i = 0; i < y_hat.size(); i++){
sum += (y_hat[i] - y[i]);
}
return sum / y_hat.size();
}
double Cost::MBE(std::vector<std::vector<double>> y_hat, std::vector<std::vector<double>> y){
double sum = 0;
for(int i = 0; i < y_hat.size(); i++){
for(int j = 0; j < y_hat[i].size(); j++){
sum += (y_hat[i][j] - y[i][j]);
}
}
return sum / y_hat.size();
}
std::vector<double> Cost::MBEDeriv(std::vector <double> y_hat, std::vector<double> y){
LinAlg alg;
return alg.onevec(y_hat.size());
}
std::vector<std::vector<double>> Cost::MBEDeriv(std::vector<std::vector<double>> y_hat, std::vector<std::vector<double>> y){
LinAlg alg;
return alg.onemat(y_hat.size(), y_hat[0].size());
}
double Cost::LogLoss(std::vector <double> y_hat, std::vector<double> y){
double sum = 0;
double eps = 1e-8;
for(int i = 0; i < y_hat.size(); i++){
sum += -(y[i] * std::log(y_hat[i] + eps) + (1 - y[i]) * std::log(1 - y_hat[i] + eps));
}
return sum / y_hat.size();
}
double Cost::LogLoss(std::vector <std::vector<double>> y_hat, std::vector <std::vector<double>> y){
double sum = 0;
double eps = 1e-8;
for(int i = 0; i < y_hat.size(); i++){
for(int j = 0; j < y_hat[i].size(); j++){
sum += -(y[i][j] * std::log(y_hat[i][j] + eps) + (1 - y[i][j]) * std::log(1 - y_hat[i][j] + eps));
}
}
return sum / y_hat.size();
}
std::vector<double> Cost::LogLossDeriv(std::vector <double> y_hat, std::vector<double> y){
LinAlg alg;
return alg.addition(alg.scalarMultiply(-1, alg.elementWiseDivision(y, y_hat)), alg.elementWiseDivision(alg.scalarMultiply(-1, alg.scalarAdd(-1, y)), alg.scalarMultiply(-1, alg.scalarAdd(-1, y_hat))));
}
std::vector<std::vector<double>> Cost::LogLossDeriv(std::vector<std::vector<double>> y_hat, std::vector<std::vector<double>> y){
LinAlg alg;
return alg.addition(alg.scalarMultiply(-1, alg.elementWiseDivision(y, y_hat)), alg.elementWiseDivision(alg.scalarMultiply(-1, alg.scalarAdd(-1, y)), alg.scalarMultiply(-1, alg.scalarAdd(-1, y_hat))));
}
double Cost::CrossEntropy(std::vector<double> y_hat, std::vector<double> y){
double sum = 0;
for(int i = 0; i < y_hat.size(); i++){
sum += y[i] * std::log(y_hat[i]);
}
return -1 * sum;
}
double Cost::CrossEntropy(std::vector<std::vector<double>> y_hat, std::vector<std::vector<double>> y){
double sum = 0;
for(int i = 0; i < y_hat.size(); i++){
for(int j = 0; j < y_hat[i].size(); j++){
sum += y[i][j] * std::log(y_hat[i][j]);
}
}
return -1 * sum;
}
std::vector<double> Cost::CrossEntropyDeriv(std::vector<double> y_hat, std::vector<double> y){
LinAlg alg;
return alg.scalarMultiply(-1, alg.elementWiseDivision(y, y_hat));
}
std::vector<std::vector<double>> Cost::CrossEntropyDeriv(std::vector<std::vector<double>> y_hat, std::vector<std::vector<double>> y){
LinAlg alg;
return alg.scalarMultiply(-1, alg.elementWiseDivision(y, y_hat));
}
double Cost::HuberLoss(std::vector <double> y_hat, std::vector<double> y, double delta){
LinAlg alg;
double sum = 0;
for(int i = 0; i < y_hat.size(); i++){
if(abs(y[i] - y_hat[i]) <= delta){
sum += (y[i] - y_hat[i]) * (y[i] - y_hat[i]);
}
else{
sum += 2 * delta * abs(y[i] - y_hat[i]) - delta * delta;
}
}
return sum;
}
double Cost::HuberLoss(std::vector<std::vector<double>> y_hat, std::vector<std::vector<double>> y, double delta){
LinAlg alg;
double sum = 0;
for(int i = 0; i < y_hat.size(); i++){
for(int j = 0; j < y_hat[i].size(); j++){
if(abs(y[i][j] - y_hat[i][j]) <= delta){
sum += (y[i][j] - y_hat[i][j]) * (y[i][j] - y_hat[i][j]);
}
else{
sum += 2 * delta * abs(y[i][j] - y_hat[i][j]) - delta * delta;
}
}
}
return sum;
}
std::vector<double> Cost::HuberLossDeriv(std::vector <double> y_hat, std::vector<double> y, double delta){
LinAlg alg;
double sum = 0;
std::vector<double> deriv;
deriv.resize(y_hat.size());
for(int i = 0; i < y_hat.size(); i++){
if(abs(y[i] - y_hat[i]) <= delta){
deriv.push_back(-(y[i] - y_hat[i]));
}
else{
if(y_hat[i] > 0 || y_hat[i] < 0){
deriv.push_back(2 * delta * (y_hat[i]/abs(y_hat[i])));
}
else{
deriv.push_back(0);
}
}
}
return deriv;
}
std::vector<std::vector<double>> Cost::HuberLossDeriv(std::vector<std::vector<double>> y_hat, std::vector<std::vector<double>> y, double delta){
LinAlg alg;
double sum = 0;
std::vector<std::vector<double>> deriv;
deriv.resize(y_hat.size());
for(int i = 0; i < deriv.size(); i++){
deriv[i].resize(y_hat[i].size());
}
for(int i = 0; i < y_hat.size(); i++){
for(int j = 0; j < y_hat[i].size(); j++){
if(abs(y[i][j] - y_hat[i][j]) <= delta){
deriv[i].push_back(-(y[i][j] - y_hat[i][j]));
}
else{
if(y_hat[i][j] > 0 || y_hat[i][j] < 0){
deriv[i].push_back(2 * delta * (y_hat[i][j]/abs(y_hat[i][j])));
}
else{
deriv[i].push_back(0);
}
}
}
}
return deriv;
}
double Cost::HingeLoss(std::vector <double> y_hat, std::vector<double> y){
double sum = 0;
for(int i = 0; i < y_hat.size(); i++){
sum += fmax(0, 1 - y[i] * y_hat[i]);
}
return sum / y_hat.size();
}
double Cost::HingeLoss(std::vector<std::vector<double>> y_hat, std::vector<std::vector<double>> y){
double sum = 0;
for(int i = 0; i < y_hat.size(); i++){
for(int j = 0; j < y_hat[i].size(); j++){
sum += fmax(0, 1 - y[i][j] * y_hat[i][j]);
}
}
return sum / y_hat.size();
}
std::vector<double> Cost::HingeLossDeriv(std::vector <double> y_hat, std::vector<double> y){
std::vector<double> deriv;
deriv.resize(y_hat.size());
for(int i = 0; i < y_hat.size(); i++){
if(1 - y[i] * y_hat[i] > 0){
deriv[i] = -y[i];
}
else{
deriv[i] = 0;
}
}
return deriv;
}
std::vector<std::vector<double>> Cost::HingeLossDeriv(std::vector<std::vector<double>> y_hat, std::vector<std::vector<double>> y){
std::vector<std::vector<double>> deriv;
for(int i = 0; i < y_hat.size(); i++){
for(int j = 0; j < y_hat[i].size(); j++){
if(1 - y[i][j] * y_hat[i][j] > 0){
deriv[i][j] = -y[i][j];
}
else{
deriv[i][j] = 0;
}
}
}
return deriv;
}
double Cost::WassersteinLoss(std::vector <double> y_hat, std::vector<double> y){
double sum = 0;
for(int i = 0; i < y_hat.size(); i++){
sum += y_hat[i] * y[i];
}
return -sum / y_hat.size();
}
double Cost::WassersteinLoss(std::vector<std::vector<double>> y_hat, std::vector<std::vector<double>> y){
double sum = 0;
for(int i = 0; i < y_hat.size(); i++){
for(int j = 0; j < y_hat[i].size(); j++){
sum += y_hat[i][j] * y[i][j];
}
}
return -sum / y_hat.size();
}
std::vector<double> Cost::WassersteinLossDeriv(std::vector<double> y_hat, std::vector<double> y){
LinAlg alg;
return alg.scalarMultiply(-1, y); // Simple.
}
std::vector<std::vector<double>> Cost::WassersteinLossDeriv(std::vector<std::vector<double>> y_hat, std::vector<std::vector<double>> y){
LinAlg alg;
return alg.scalarMultiply(-1, y); // Simple.
}
double Cost::HingeLoss(std::vector <double> y_hat, std::vector<double> y, std::vector<double> weights, double C){
LinAlg alg;
Reg regularization;
return C * HingeLoss(y_hat, y) + regularization.regTerm(weights, 1, 0, "Ridge");
}
double Cost::HingeLoss(std::vector<std::vector<double>> y_hat, std::vector<std::vector<double>> y, std::vector<std::vector<double>> weights, double C){
LinAlg alg;
Reg regularization;
return C * HingeLoss(y_hat, y) + regularization.regTerm(weights, 1, 0, "Ridge");
}
std::vector<double> Cost::HingeLossDeriv(std::vector <double> y_hat, std::vector<double> y, double C){
LinAlg alg;
Reg regularization;
return alg.scalarMultiply(C, HingeLossDeriv(y_hat, y));
}
std::vector<std::vector<double>> Cost::HingeLossDeriv(std::vector<std::vector<double>> y_hat, std::vector<std::vector<double>> y, double C){
LinAlg alg;
Reg regularization;
return alg.scalarMultiply(C, HingeLossDeriv(y_hat, y));
}
double Cost::dualFormSVM(std::vector<double> alpha, std::vector<std::vector<double>> X, std::vector<double> y){
LinAlg alg;
std::vector<std::vector<double>> Y = alg.diag(y); // Y is a diagnoal matrix. Y[i][j] = y[i] if i = i, else Y[i][j] = 0. Yt = Y.
std::vector<std::vector<double>> K = alg.matmult(X, alg.transpose(X)); // TO DO: DON'T forget to add non-linear kernelizations.
std::vector<std::vector<double>> Q = alg.matmult(alg.matmult(alg.transpose(Y), K), Y);
double alphaQ = alg.matmult(alg.matmult({alpha}, Q), alg.transpose({alpha}))[0][0];
std::vector<double> one = alg.onevec(alpha.size());
return -alg.dot(one, alpha) + 0.5 * alphaQ;
}
std::vector<double> Cost::dualFormSVMDeriv(std::vector<double> alpha, std::vector<std::vector<double>> X, std::vector<double> y){
LinAlg alg;
std::vector<std::vector<double>> Y = alg.zeromat(y.size(), y.size());
for(int i = 0; i < y.size(); i++){
Y[i][i] = y[i]; // Y is a diagnoal matrix. Y[i][j] = y[i] if i = i, else Y[i][j] = 0. Yt = Y.
}
std::vector<std::vector<double>> K = alg.matmult(X, alg.transpose(X)); // TO DO: DON'T forget to add non-linear kernelizations.
std::vector<std::vector<double>> Q = alg.matmult(alg.matmult(alg.transpose(Y), K), Y);
std::vector<double> alphaQDeriv = alg.mat_vec_mult(Q, alpha);
std::vector<double> one = alg.onevec(alpha.size());
return alg.subtraction(alphaQDeriv, one);
}
}