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

290 lines
15 KiB
C++

//
// GAN.cpp
//
// Created by Marc Melikyan on 11/4/20.
//
#include "gan.h"
#include "../activation/activation.h"
#include "../lin_alg/lin_alg.h"
#include "../regularization/reg.h"
#include "../utilities/utilities.h"
#include "../cost/cost.h"
#include <iostream>
#include <cmath>
namespace MLPP {
GAN::GAN(double k, std::vector<std::vector<double>> outputSet)
: outputSet(outputSet), n(outputSet.size()), k(k)
{
}
GAN::~GAN(){
delete outputLayer;
}
std::vector<std::vector<double>> GAN::generateExample(int n){
LinAlg alg;
return modelSetTestGenerator(alg.gaussianNoise(n, k));
}
void GAN::gradientDescent(double learning_rate, int max_epoch, bool UI){
class Cost cost;
LinAlg alg;
double cost_prev = 0;
int epoch = 1;
forwardPass();
while(true){
cost_prev = Cost(y_hat, alg.onevec(n));
// Training of the discriminator.
std::vector<std::vector<double>> generatorInputSet = alg.gaussianNoise(n, k);
std::vector<std::vector<double>> discriminatorInputSet = modelSetTestGenerator(generatorInputSet);
discriminatorInputSet.insert(discriminatorInputSet.end(), outputSet.begin(), outputSet.end()); // Fake + real inputs.
std::vector<double> y_hat = modelSetTestDiscriminator(discriminatorInputSet);
std::vector<double> outputSet = alg.zerovec(n);
std::vector<double> outputSetReal = alg.onevec(n);
outputSet.insert(outputSet.end(), outputSetReal.begin(), outputSetReal.end()); // Fake + real output scores.
auto [cumulativeDiscriminatorHiddenLayerWGrad, outputDiscriminatorWGrad] = computeDiscriminatorGradients(y_hat, outputSet);
cumulativeDiscriminatorHiddenLayerWGrad = alg.scalarMultiply(learning_rate/n, cumulativeDiscriminatorHiddenLayerWGrad);
outputDiscriminatorWGrad = alg.scalarMultiply(learning_rate/n, outputDiscriminatorWGrad);
updateDiscriminatorParameters(cumulativeDiscriminatorHiddenLayerWGrad, outputDiscriminatorWGrad, learning_rate);
// Training of the generator.
generatorInputSet = alg.gaussianNoise(n, k);
discriminatorInputSet = modelSetTestGenerator(generatorInputSet);
y_hat = modelSetTestDiscriminator(discriminatorInputSet);
outputSet = alg.onevec(n);
std::vector<std::vector<std::vector<double>>> cumulativeGeneratorHiddenLayerWGrad = computeGeneratorGradients(y_hat, outputSet);
cumulativeGeneratorHiddenLayerWGrad = alg.scalarMultiply(learning_rate/n, cumulativeGeneratorHiddenLayerWGrad);
updateGeneratorParameters(cumulativeGeneratorHiddenLayerWGrad, learning_rate);
forwardPass();
if(UI) { GAN::UI(epoch, cost_prev, GAN::y_hat, alg.onevec(n)); }
epoch++;
if(epoch > max_epoch) { break; }
}
}
double GAN::score(){
LinAlg alg;
Utilities util;
forwardPass();
return util.performance(y_hat, alg.onevec(n));
}
void GAN::save(std::string fileName){
Utilities util;
if(!network.empty()){
util.saveParameters(fileName, network[0].weights, network[0].bias, 0, 1);
for(int i = 1; i < network.size(); i++){
util.saveParameters(fileName, network[i].weights, network[i].bias, 1, i + 1);
}
util.saveParameters(fileName, outputLayer->weights, outputLayer->bias, 1, network.size() + 1);
}
else{
util.saveParameters(fileName, outputLayer->weights, outputLayer->bias, 0, network.size() + 1);
}
}
void GAN::addLayer(int n_hidden, std::string activation, std::string weightInit, std::string reg, double lambda, double alpha){
LinAlg alg;
if(network.empty()){
network.push_back(HiddenLayer(n_hidden, activation, alg.gaussianNoise(n, k), weightInit, reg, lambda, alpha));
network[0].forwardPass();
}
else{
network.push_back(HiddenLayer(n_hidden, activation, network[network.size() - 1].a, weightInit, reg, lambda, alpha));
network[network.size() - 1].forwardPass();
}
}
void GAN::addOutputLayer(std::string weightInit, std::string reg, double lambda, double alpha){
LinAlg alg;
if(!network.empty()){
outputLayer = new OutputLayer(network[network.size() - 1].n_hidden, "Sigmoid", "LogLoss", network[network.size() - 1].a, weightInit, reg, lambda, alpha);
}
else{
outputLayer = new OutputLayer(k, "Sigmoid", "LogLoss", alg.gaussianNoise(n, k), weightInit, reg, lambda, alpha);
}
}
std::vector<std::vector<double>> GAN::modelSetTestGenerator(std::vector<std::vector<double>> X){
if(!network.empty()){
network[0].input = X;
network[0].forwardPass();
for(int i = 1; i <= network.size()/2; i++){
network[i].input = network[i - 1].a;
network[i].forwardPass();
}
}
return network[network.size()/2].a;
}
std::vector<double> GAN::modelSetTestDiscriminator(std::vector<std::vector<double>> X){
if(!network.empty()){
for(int i = network.size()/2 + 1; i < network.size(); i++){
if(i == network.size()/2 + 1){
network[i].input = X;
}
else { network[i].input = network[i - 1].a; }
network[i].forwardPass();
}
outputLayer->input = network[network.size() - 1].a;
}
outputLayer->forwardPass();
return outputLayer->a;
}
double GAN::Cost(std::vector<double> y_hat, std::vector<double> y){
Reg regularization;
class Cost cost;
double totalRegTerm = 0;
auto cost_function = outputLayer->cost_map[outputLayer->cost];
if(!network.empty()){
for(int i = 0; i < network.size() - 1; i++){
totalRegTerm += regularization.regTerm(network[i].weights, network[i].lambda, network[i].alpha, network[i].reg);
}
}
return (cost.*cost_function)(y_hat, y) + totalRegTerm + regularization.regTerm(outputLayer->weights, outputLayer->lambda, outputLayer->alpha, outputLayer->reg);
}
void GAN::forwardPass(){
LinAlg alg;
if(!network.empty()){
network[0].input = alg.gaussianNoise(n, k);
network[0].forwardPass();
for(int i = 1; i < network.size(); i++){
network[i].input = network[i - 1].a;
network[i].forwardPass();
}
outputLayer->input = network[network.size() - 1].a;
}
else{ // Should never happen, though.
outputLayer->input = alg.gaussianNoise(n, k);
}
outputLayer->forwardPass();
y_hat = outputLayer->a;
}
void GAN::updateDiscriminatorParameters(std::vector<std::vector<std::vector<double>>> hiddenLayerUpdations, std::vector<double> outputLayerUpdation, double learning_rate){
LinAlg alg;
outputLayer->weights = alg.subtraction(outputLayer->weights, outputLayerUpdation);
outputLayer->bias -= learning_rate * alg.sum_elements(outputLayer->delta) / n;
if(!network.empty()){
network[network.size() - 1].weights = alg.subtraction(network[network.size() - 1].weights, hiddenLayerUpdations[0]);
network[network.size() - 1].bias = alg.subtractMatrixRows(network[network.size() - 1].bias, alg.scalarMultiply(learning_rate/n, network[network.size() - 1].delta));
for(int i = network.size() - 2; i > network.size()/2; i--){
network[i].weights = alg.subtraction(network[i].weights, hiddenLayerUpdations[(network.size() - 2) - i + 1]);
network[i].bias = alg.subtractMatrixRows(network[i].bias, alg.scalarMultiply(learning_rate/n, network[i].delta));
}
}
}
void GAN::updateGeneratorParameters(std::vector<std::vector<std::vector<double>>> hiddenLayerUpdations, double learning_rate){
LinAlg alg;
if(!network.empty()){
for(int i = network.size()/2; i >= 0; i--){
//std::cout << network[i].weights.size() << "x" << network[i].weights[0].size() << std::endl;
//std::cout << hiddenLayerUpdations[(network.size() - 2) - i + 1].size() << "x" << hiddenLayerUpdations[(network.size() - 2) - i + 1][0].size() << std::endl;
network[i].weights = alg.subtraction(network[i].weights, hiddenLayerUpdations[(network.size() - 2) - i + 1]);
network[i].bias = alg.subtractMatrixRows(network[i].bias, alg.scalarMultiply(learning_rate/n, network[i].delta));
}
}
}
std::tuple<std::vector<std::vector<std::vector<double>>>, std::vector<double>> GAN::computeDiscriminatorGradients(std::vector<double> y_hat, std::vector<double> outputSet){
class Cost cost;
Activation avn;
LinAlg alg;
Reg regularization;
std::vector<std::vector<std::vector<double>>> cumulativeHiddenLayerWGrad; // Tensor containing ALL hidden grads.
auto costDeriv = outputLayer->costDeriv_map[outputLayer->cost];
auto outputAvn = outputLayer->activation_map[outputLayer->activation];
outputLayer->delta = alg.hadamard_product((cost.*costDeriv)(y_hat, outputSet), (avn.*outputAvn)(outputLayer->z, 1));
std::vector<double> outputWGrad = alg.mat_vec_mult(alg.transpose(outputLayer->input), outputLayer->delta);
outputWGrad = alg.addition(outputWGrad, regularization.regDerivTerm(outputLayer->weights, outputLayer->lambda, outputLayer->alpha, outputLayer->reg));
if(!network.empty()){
auto hiddenLayerAvn = network[network.size() - 1].activation_map[network[network.size() - 1].activation];
network[network.size() - 1].delta = alg.hadamard_product(alg.outerProduct(outputLayer->delta, outputLayer->weights), (avn.*hiddenLayerAvn)(network[network.size() - 1].z, 1));
std::vector<std::vector<double>> hiddenLayerWGrad = alg.matmult(alg.transpose(network[network.size() - 1].input), network[network.size() - 1].delta);
cumulativeHiddenLayerWGrad.push_back(alg.addition(hiddenLayerWGrad, regularization.regDerivTerm(network[network.size() - 1].weights, network[network.size() - 1].lambda, network[network.size() - 1].alpha, network[network.size() - 1].reg))); // Adding to our cumulative hidden layer grads. Maintain reg terms as well.
//std::cout << "HIDDENLAYER FIRST:" << hiddenLayerWGrad.size() << "x" << hiddenLayerWGrad[0].size() << std::endl;
//std::cout << "WEIGHTS SECOND:" << network[network.size() - 1].weights.size() << "x" << network[network.size() - 1].weights[0].size() << std::endl;
for(int i = network.size() - 2; i > network.size()/2; i--){
auto hiddenLayerAvn = network[i].activation_map[network[i].activation];
network[i].delta = alg.hadamard_product(alg.matmult(network[i + 1].delta, alg.transpose(network[i + 1].weights)), (avn.*hiddenLayerAvn)(network[i].z, 1));
std::vector<std::vector<double>> hiddenLayerWGrad = alg.matmult(alg.transpose(network[i].input), network[i].delta);
cumulativeHiddenLayerWGrad.push_back(alg.addition(hiddenLayerWGrad, regularization.regDerivTerm(network[i].weights, network[i].lambda, network[i].alpha, network[i].reg))); // Adding to our cumulative hidden layer grads. Maintain reg terms as well.
}
}
return {cumulativeHiddenLayerWGrad, outputWGrad};
}
std::vector<std::vector<std::vector<double>>> GAN::computeGeneratorGradients(std::vector<double> y_hat, std::vector<double> outputSet){
class Cost cost;
Activation avn;
LinAlg alg;
Reg regularization;
std::vector<std::vector<std::vector<double>>> cumulativeHiddenLayerWGrad; // Tensor containing ALL hidden grads.
auto costDeriv = outputLayer->costDeriv_map[outputLayer->cost];
auto outputAvn = outputLayer->activation_map[outputLayer->activation];
outputLayer->delta = alg.hadamard_product((cost.*costDeriv)(y_hat, outputSet), (avn.*outputAvn)(outputLayer->z, 1));
std::vector<double> outputWGrad = alg.mat_vec_mult(alg.transpose(outputLayer->input), outputLayer->delta);
outputWGrad = alg.addition(outputWGrad, regularization.regDerivTerm(outputLayer->weights, outputLayer->lambda, outputLayer->alpha, outputLayer->reg));
if(!network.empty()){
auto hiddenLayerAvn = network[network.size() - 1].activation_map[network[network.size() - 1].activation];
network[network.size() - 1].delta = alg.hadamard_product(alg.outerProduct(outputLayer->delta, outputLayer->weights), (avn.*hiddenLayerAvn)(network[network.size() - 1].z, 1));
std::vector<std::vector<double>> hiddenLayerWGrad = alg.matmult(alg.transpose(network[network.size() - 1].input), network[network.size() - 1].delta);
cumulativeHiddenLayerWGrad.push_back(alg.addition(hiddenLayerWGrad, regularization.regDerivTerm(network[network.size() - 1].weights, network[network.size() - 1].lambda, network[network.size() - 1].alpha, network[network.size() - 1].reg))); // Adding to our cumulative hidden layer grads. Maintain reg terms as well.
for(int i = network.size() - 2; i >= 0; i--){
auto hiddenLayerAvn = network[i].activation_map[network[i].activation];
network[i].delta = alg.hadamard_product(alg.matmult(network[i + 1].delta, alg.transpose(network[i + 1].weights)), (avn.*hiddenLayerAvn)(network[i].z, 1));
std::vector<std::vector<double>> hiddenLayerWGrad = alg.matmult(alg.transpose(network[i].input), network[i].delta);
cumulativeHiddenLayerWGrad.push_back(alg.addition(hiddenLayerWGrad, regularization.regDerivTerm(network[i].weights, network[i].lambda, network[i].alpha, network[i].reg))); // Adding to our cumulative hidden layer grads. Maintain reg terms as well.
}
}
return cumulativeHiddenLayerWGrad;
}
void GAN::UI(int epoch, double cost_prev, std::vector<double> y_hat, std::vector<double> outputSet){
Utilities::CostInfo(epoch, cost_prev, Cost(y_hat, outputSet));
std::cout << "Layer " << network.size() + 1 << ": " << std::endl;
Utilities::UI(outputLayer->weights, outputLayer->bias);
if(!network.empty()){
for(int i = network.size() - 1; i >= 0; i--){
std::cout << "Layer " << i + 1 << ": " << std::endl;
Utilities::UI(network[i].weights, network[i].bias);
}
}
}
}