pmlpp/mlpp/gan/gan.cpp

286 lines
13 KiB
C++

//
// GAN.cpp
//
// Created by Marc Melikyan on 11/4/20.
//
#include "gan.h"
#include "../activation/activation.h"
#include "../cost/cost.h"
#include "../lin_alg/lin_alg.h"
#include "../regularization/reg.h"
#include "../utilities/utilities.h"
#include <cmath>
#include <iostream>
MLPPGAN::MLPPGAN(real_t k, std::vector<std::vector<real_t>> outputSet) :
outputSet(outputSet), n(outputSet.size()), k(k) {
}
MLPPGAN::~MLPPGAN() {
delete outputLayer;
}
std::vector<std::vector<real_t>> MLPPGAN::generateExample(int n) {
MLPPLinAlg alg;
return modelSetTestGenerator(alg.gaussianNoise(n, k));
}
void MLPPGAN::gradientDescent(real_t learning_rate, int max_epoch, bool UI) {
class MLPPCost cost;
MLPPLinAlg alg;
real_t 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<real_t>> generatorInputSet = alg.gaussianNoise(n, k);
std::vector<std::vector<real_t>> discriminatorInputSet = modelSetTestGenerator(generatorInputSet);
discriminatorInputSet.insert(discriminatorInputSet.end(), outputSet.begin(), outputSet.end()); // Fake + real inputs.
std::vector<real_t> y_hat = modelSetTestDiscriminator(discriminatorInputSet);
std::vector<real_t> outputSet = alg.zerovec(n);
std::vector<real_t> 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<real_t>>> cumulativeGeneratorHiddenLayerWGrad = computeGeneratorGradients(y_hat, outputSet);
cumulativeGeneratorHiddenLayerWGrad = alg.scalarMultiply(learning_rate / n, cumulativeGeneratorHiddenLayerWGrad);
updateGeneratorParameters(cumulativeGeneratorHiddenLayerWGrad, learning_rate);
forwardPass();
if (UI) {
MLPPGAN::UI(epoch, cost_prev, MLPPGAN::y_hat, alg.onevec(n));
}
epoch++;
if (epoch > max_epoch) {
break;
}
}
}
real_t MLPPGAN::score() {
MLPPLinAlg alg;
MLPPUtilities util;
forwardPass();
return util.performance(y_hat, alg.onevec(n));
}
void MLPPGAN::save(std::string fileName) {
MLPPUtilities 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 MLPPGAN::addLayer(int n_hidden, std::string activation, std::string weightInit, std::string reg, real_t lambda, real_t alpha) {
MLPPLinAlg alg;
if (network.empty()) {
network.push_back(MLPPOldHiddenLayer(n_hidden, activation, alg.gaussianNoise(n, k), weightInit, reg, lambda, alpha));
network[0].forwardPass();
} else {
network.push_back(MLPPOldHiddenLayer(n_hidden, activation, network[network.size() - 1].a, weightInit, reg, lambda, alpha));
network[network.size() - 1].forwardPass();
}
}
void MLPPGAN::addOutputLayer(std::string weightInit, std::string reg, real_t lambda, real_t alpha) {
MLPPLinAlg alg;
if (!network.empty()) {
outputLayer = new MLPPOldOutputLayer(network[network.size() - 1].n_hidden, "Sigmoid", "LogLoss", network[network.size() - 1].a, weightInit, reg, lambda, alpha);
} else {
outputLayer = new MLPPOldOutputLayer(k, "Sigmoid", "LogLoss", alg.gaussianNoise(n, k), weightInit, reg, lambda, alpha);
}
}
std::vector<std::vector<real_t>> MLPPGAN::modelSetTestGenerator(std::vector<std::vector<real_t>> 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<real_t> MLPPGAN::modelSetTestDiscriminator(std::vector<std::vector<real_t>> 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;
}
real_t MLPPGAN::Cost(std::vector<real_t> y_hat, std::vector<real_t> y) {
MLPPReg regularization;
class MLPPCost cost;
real_t 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 MLPPGAN::forwardPass() {
MLPPLinAlg 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 MLPPGAN::updateDiscriminatorParameters(std::vector<std::vector<std::vector<real_t>>> hiddenLayerUpdations, std::vector<real_t> outputLayerUpdation, real_t learning_rate) {
MLPPLinAlg 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 MLPPGAN::updateGeneratorParameters(std::vector<std::vector<std::vector<real_t>>> hiddenLayerUpdations, real_t learning_rate) {
MLPPLinAlg 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<real_t>>>, std::vector<real_t>> MLPPGAN::computeDiscriminatorGradients(std::vector<real_t> y_hat, std::vector<real_t> outputSet) {
class MLPPCost cost;
MLPPActivation avn;
MLPPLinAlg alg;
MLPPReg regularization;
std::vector<std::vector<std::vector<real_t>>> 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<real_t> 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<real_t>> 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<real_t>> 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<real_t>>> MLPPGAN::computeGeneratorGradients(std::vector<real_t> y_hat, std::vector<real_t> outputSet) {
class MLPPCost cost;
MLPPActivation avn;
MLPPLinAlg alg;
MLPPReg regularization;
std::vector<std::vector<std::vector<real_t>>> 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<real_t> 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<real_t>> 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<real_t>> 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 MLPPGAN::UI(int epoch, real_t cost_prev, std::vector<real_t> y_hat, std::vector<real_t> outputSet) {
MLPPUtilities::CostInfo(epoch, cost_prev, Cost(y_hat, outputSet));
std::cout << "Layer " << network.size() + 1 << ": " << std::endl;
MLPPUtilities::UI(outputLayer->weights, outputLayer->bias);
if (!network.empty()) {
for (int i = network.size() - 1; i >= 0; i--) {
std::cout << "Layer " << i + 1 << ": " << std::endl;
MLPPUtilities::UI(network[i].weights, network[i].bias);
}
}
}