pmlpp/mlpp/gaussian_nb/gaussian_nb_old.cpp

90 lines
2.6 KiB
C++

//
// GaussianNB.cpp
//
// Created by Marc Melikyan on 1/17/21.
//
#include "gaussian_nb_old.h"
#include "../lin_alg/lin_alg_old.h"
#include "../stat/stat_old.h"
#include "../utilities/utilities.h"
#include <algorithm>
#include <iostream>
#include <random>
MLPPGaussianNBOld::MLPPGaussianNBOld(std::vector<std::vector<real_t>> p_inputSet, std::vector<real_t> p_outputSet, int p_class_num) {
inputSet = p_inputSet;
outputSet = p_outputSet;
class_num = p_class_num;
y_hat.resize(outputSet.size());
Evaluate();
}
std::vector<real_t> MLPPGaussianNBOld::modelSetTest(std::vector<std::vector<real_t>> X) {
std::vector<real_t> y_hat;
for (uint32_t i = 0; i < X.size(); i++) {
y_hat.push_back(modelTest(X[i]));
}
return y_hat;
}
real_t MLPPGaussianNBOld::modelTest(std::vector<real_t> x) {
real_t score[class_num];
real_t y_hat_i = 1;
for (int i = class_num - 1; i >= 0; i--) {
y_hat_i += std::log(priors[i] * (1 / sqrt(2 * M_PI * sigma[i] * sigma[i])) * exp(-(x[i] * mu[i]) * (x[i] * mu[i]) / (2 * sigma[i] * sigma[i])));
score[i] = exp(y_hat_i);
}
return std::distance(score, std::max_element(score, score + sizeof(score) / sizeof(real_t)));
}
real_t MLPPGaussianNBOld::score() {
MLPPUtilities util;
return util.performance(y_hat, outputSet);
}
void MLPPGaussianNBOld::Evaluate() {
MLPPStatOld stat;
MLPPLinAlgOld alg;
// Computing mu_k_y and sigma_k_y
mu.resize(class_num);
sigma.resize(class_num);
for (int i = class_num - 1; i >= 0; i--) {
std::vector<real_t> set;
for (uint32_t j = 0; j < inputSet.size(); j++) {
for (uint32_t k = 0; k < inputSet[j].size(); k++) {
if (outputSet[j] == i) {
set.push_back(inputSet[j][k]);
}
}
}
mu[i] = stat.mean(set);
sigma[i] = stat.standardDeviation(set);
}
// Priors
priors.resize(class_num);
for (uint32_t i = 0; i < outputSet.size(); i++) {
priors[int(outputSet[i])]++;
}
priors = alg.scalarMultiply(real_t(1) / real_t(outputSet.size()), priors);
for (uint32_t i = 0; i < outputSet.size(); i++) {
real_t score[class_num];
real_t y_hat_i = 1;
for (int j = class_num - 1; j >= 0; j--) {
for (uint32_t k = 0; k < inputSet[i].size(); k++) {
y_hat_i += std::log(priors[j] * (1 / sqrt(2 * M_PI * sigma[j] * sigma[j])) * exp(-(inputSet[i][k] * mu[j]) * (inputSet[i][k] * mu[j]) / (2 * sigma[j] * sigma[j])));
}
score[j] = exp(y_hat_i);
std::cout << score[j] << std::endl;
}
y_hat[i] = std::distance(score, std::max_element(score, score + sizeof(score) / sizeof(real_t)));
std::cout << std::distance(score, std::max_element(score, score + sizeof(score) / sizeof(real_t))) << std::endl;
}
}