pmlpp/dual_svc/dual_svc.cpp

326 lines
10 KiB
C++

/*************************************************************************/
/* dual_svc.cpp */
/*************************************************************************/
/* This file is part of: */
/* PMLPP Machine Learning Library */
/* https://github.com/Relintai/pmlpp */
/*************************************************************************/
/* Copyright (c) 2023-present Péter Magyar. */
/* Copyright (c) 2022-2023 Marc Melikyan */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#include "dual_svc.h"
#include "../activation/activation.h"
#include "../cost/cost.h"
#include "../regularization/reg.h"
#include "../utilities/utilities.h"
#include <random>
Ref<MLPPVector> MLPPDualSVC::model_set_test(const Ref<MLPPMatrix> &X) {
return evaluatem(X);
}
real_t MLPPDualSVC::model_test(const Ref<MLPPVector> &x) {
return evaluatev(x);
}
void MLPPDualSVC::gradient_descent(real_t learning_rate, int max_epoch, bool ui) {
MLPPCost mlpp_cost;
MLPPActivation avn;
MLPPReg regularization;
real_t cost_prev = 0;
int epoch = 1;
forward_pass();
Ref<MLPPVector> input_set_i_row_tmp;
input_set_i_row_tmp.instance();
input_set_i_row_tmp->resize(_input_set->size().x);
Ref<MLPPVector> input_set_j_row_tmp;
input_set_j_row_tmp.instance();
input_set_j_row_tmp->resize(_input_set->size().x);
while (true) {
cost_prev = cost(_alpha, _input_set, _output_set);
_alpha->sub(mlpp_cost.dual_form_svm_deriv(_alpha, _input_set, _output_set)->scalar_multiplyn(learning_rate));
alpha_projection();
// Calculating the bias
real_t biasGradient = 0;
for (int i = 0; i < _alpha->size(); i++) {
real_t sum = 0;
if (_alpha->element_get(i) < _C && _alpha->element_get(i) > 0) {
for (int j = 0; j < _alpha->size(); j++) {
if (_alpha->element_get(j) > 0) {
_input_set->row_get_into_mlpp_vector(i, input_set_i_row_tmp);
_input_set->row_get_into_mlpp_vector(j, input_set_j_row_tmp);
sum += _alpha->element_get(j) * _output_set->element_get(j) * input_set_j_row_tmp->dot(input_set_i_row_tmp); // TO DO: DON'T forget to add non-linear kernelizations.
}
}
}
biasGradient = (1 - _output_set->element_get(i) * sum) / _output_set->element_get(i);
break;
}
_bias -= biasGradient * learning_rate;
forward_pass();
// UI PORTION
if (ui) {
MLPPUtilities::cost_info(epoch, cost_prev, cost(_alpha, _input_set, _output_set));
MLPPUtilities::print_ui_vb(_alpha, _bias);
}
epoch++;
if (epoch > max_epoch) {
break;
}
}
}
// void MLPPDualSVC::SGD(real_t learning_rate, int max_epoch, bool UI){
// class MLPPCost cost;
// MLPPActivation avn;
// MLPPLinAlg alg;
// MLPPReg regularization;
// real_t cost_prev = 0;
// int epoch = 1;
// while(true){
// std::random_device rd;
// std::default_random_engine generator(rd());
// std::uniform_int_distribution<int> distribution(0, int(n - 1));
// int outputIndex = distribution(generator);
// cost_prev = Cost(alpha, _input_set[outputIndex], _output_set[outputIndex]);
// // Bias updation
// bias -= learning_rate * costDeriv;
// y_hat = Evaluate({_input_set[outputIndex]});
// if(UI) {
// MLPPUtilities::CostInfo(epoch, cost_prev, Cost(alpha));
// MLPPUtilities::UI(weights, bias);
// }
// epoch++;
// if(epoch > max_epoch) { break; }
// }
// forwardPass();
// }
// void MLPPDualSVC::MBGD(real_t learning_rate, int max_epoch, int mini_batch_size, bool UI){
// class MLPPCost cost;
// MLPPActivation avn;
// MLPPLinAlg alg;
// MLPPReg regularization;
// real_t cost_prev = 0;
// int epoch = 1;
// // Creating the mini-batches
// int n_mini_batch = n/mini_batch_size;
// auto [inputMiniBatches, outputMiniBatches] = MLPPUtilities::createMiniBatches(_input_set, _output_set, n_mini_batch);
// while(true){
// for(int i = 0; i < n_mini_batch; i++){
// std::vector<real_t> y_hat = Evaluate(inputMiniBatches[i]);
// std::vector<real_t> z = propagate(inputMiniBatches[i]);
// cost_prev = Cost(z, outputMiniBatches[i], weights, C);
// // Calculating the weight gradients
// weights = alg.subtraction(weights, alg.scalarMultiply(learning_rate/n, alg.mat_vec_mult(alg.transpose(inputMiniBatches[i]), cost.HingeLossDeriv(z, outputMiniBatches[i], C))));
// weights = regularization.regWeights(weights, learning_rate/n, 0, "Ridge");
// // Calculating the bias gradients
// bias -= learning_rate * alg.sum_elements(cost.HingeLossDeriv(y_hat, outputMiniBatches[i], C)) / n;
// forwardPass();
// y_hat = Evaluate(inputMiniBatches[i]);
// if(UI) {
// MLPPUtilities::CostInfo(epoch, cost_prev, Cost(z, outputMiniBatches[i], weights, C));
// MLPPUtilities::UI(weights, bias);
// }
// }
// epoch++;
// if(epoch > max_epoch) { break; }
// }
// forwardPass();
// }
real_t MLPPDualSVC::score() {
MLPPUtilities util;
return util.performance_vec(_y_hat, _output_set);
}
void MLPPDualSVC::save(const String &file_name) {
MLPPUtilities util;
//util.saveParameters(file_name, _alpha, _bias);
}
MLPPDualSVC::MLPPDualSVC(const Ref<MLPPMatrix> &p_input_set, const Ref<MLPPVector> &p_output_set, real_t p_C, KernelMethod p_kernel) {
_input_set = p_input_set;
_output_set = p_output_set;
_n = p_input_set->size().y;
_k = p_input_set->size().x;
_C = p_C;
_kernel = p_kernel;
_z.instance();
_y_hat.instance();
_alpha.instance();
_y_hat->resize(_n);
MLPPUtilities utils;
_bias = utils.bias_initializationr();
_alpha->resize(_n);
utils.weight_initializationv(_alpha); // One alpha for all training examples, as per the lagrangian multipliers.
_K = kernel_functionm(_input_set, _input_set, _kernel); // For now this is unused. When non-linear kernels are added, the K will be manipulated.
}
MLPPDualSVC::MLPPDualSVC() {
}
MLPPDualSVC::~MLPPDualSVC() {
}
real_t MLPPDualSVC::cost(const Ref<MLPPVector> &alpha, const Ref<MLPPMatrix> &X, const Ref<MLPPVector> &y) {
class MLPPCost cost;
return cost.dual_form_svm(alpha, X, y);
}
real_t MLPPDualSVC::evaluatev(const Ref<MLPPVector> &x) {
MLPPActivation avn;
return avn.sign_normr(propagatev(x));
}
real_t MLPPDualSVC::propagatev(const Ref<MLPPVector> &x) {
real_t z = 0;
Ref<MLPPVector> input_set_row_tmp;
input_set_row_tmp.instance();
input_set_row_tmp->resize(_input_set->size().x);
for (int j = 0; j < _alpha->size(); j++) {
if (_alpha->element_get(j) != 0) {
_input_set->row_get_into_mlpp_vector(j, input_set_row_tmp);
z += _alpha->element_get(j) * _output_set->element_get(j) * input_set_row_tmp->dot(x); // TO DO: DON'T forget to add non-linear kernelizations.
}
}
z += _bias;
return z;
}
Ref<MLPPVector> MLPPDualSVC::evaluatem(const Ref<MLPPMatrix> &X) {
MLPPActivation avn;
return avn.sign_normv(propagatem(X));
}
Ref<MLPPVector> MLPPDualSVC::propagatem(const Ref<MLPPMatrix> &X) {
Ref<MLPPVector> z;
z.instance();
z->resize(X->size().y);
Ref<MLPPVector> input_set_row_tmp;
input_set_row_tmp.instance();
input_set_row_tmp->resize(_input_set->size().x);
Ref<MLPPVector> x_row_tmp;
x_row_tmp.instance();
x_row_tmp->resize(X->size().x);
for (int i = 0; i < X->size().y; i++) {
real_t sum = 0;
for (int j = 0; j < _alpha->size(); j++) {
if (_alpha->element_get(j) != 0) {
_input_set->row_get_into_mlpp_vector(j, input_set_row_tmp);
X->row_get_into_mlpp_vector(i, x_row_tmp);
sum += _alpha->element_get(j) * _output_set->element_get(j) * input_set_row_tmp->dot(x_row_tmp); // TO DO: DON'T forget to add non-linear kernelizations.
}
}
sum += _bias;
z->element_set(i, sum);
}
return z;
}
void MLPPDualSVC::forward_pass() {
MLPPActivation avn;
_z = propagatem(_input_set);
_y_hat = avn.sign_normv(_z);
}
void MLPPDualSVC::alpha_projection() {
for (int i = 0; i < _alpha->size(); i++) {
if (_alpha->element_get(i) > _C) {
_alpha->element_set(i, _C);
} else if (_alpha->element_get(i) < 0) {
_alpha->element_set(i, 0);
}
}
}
real_t MLPPDualSVC::kernel_functionv(const Ref<MLPPVector> &v, const Ref<MLPPVector> &u, KernelMethod kernel) {
if (kernel == KERNEL_METHOD_LINEAR) {
return u->dot(v);
}
return 0;
}
Ref<MLPPMatrix> MLPPDualSVC::kernel_functionm(const Ref<MLPPMatrix> &U, const Ref<MLPPMatrix> &V, KernelMethod kernel) {
if (kernel == KERNEL_METHOD_LINEAR) {
return _input_set->multn(_input_set->transposen());
}
Ref<MLPPMatrix> m;
m.instance();
return m;
}
void MLPPDualSVC::_bind_methods() {
}