BackProp Fixes

This commit is contained in:
IlyaShurupov 2023-10-25 11:03:15 +03:00
parent efbb09f8ba
commit 0542b7ba2e
11 changed files with 189 additions and 106 deletions

View file

@ -1,139 +1,142 @@
// #include "NewPlacement.hpp"
#include "FullyConnectedNN.hpp"
#include "NewPlacement.hpp"
#include "Utils.hpp"
#include <cmath>
using namespace tp;
static halnf sigmoid(halnf val) { return 0; }
static halnf linearFun(halnf val) { return val; }
static halnf linearFunDerivative(halnf val) { return 1; }
static halnf sigmoid(double val) { return 1.0f / (1.0f + (halnf) exp(-val)); }
static halnf sigmoidDerivative(double val) {
halnf sigmoid_val = sigmoid(val);
return sigmoid_val * (1.0f - sigmoid_val);
}
static halnf relu(halnf val) { return val < 0 ? 0 : val; }
static halnf reluDerivative(halnf val) { return val < 0 ? 0 : 1; }
void FullyConnectedNN::initializeRandom(Buffer<halni> description) {
static halnf activationFunction(halnf val) { return sigmoid(val); }
static halnf activationFunctionDerivative(halnf val) { return sigmoidDerivative(val); }
void FullyConnectedNN::initializeRandom(const Buffer<halni>& description) {
ASSERT(description.size() > 1);
mLayers.reserve(description.size());
for (auto i : Range<halni>(0, (halni) description.size())) {
mLayers[i].mNeurons.reserve(description[i]);
mLayers[i].neurons.reserve(description[i]);
if (i == 0) {
continue;
}
for (auto neuron : mLayers[i].mNeurons) {
neuron->mWeights.reserve(description[i - 1]);
for (auto weight : neuron->mWeights) {
weight.data() = (halnf) (randomFloat() - 0.5) * 2;
for (auto neuron : mLayers[i].neurons) {
neuron->weights.reserve(description[i - 1]);
for (auto weight : neuron->weights) {
weight->val = (halnf) (randomFloat() - 0) * 2;
}
neuron->mBias = (halnf) (randomFloat() - 0.5) * 2;
neuron->bias.val = (halnf) (randomFloat() - 0) * 2;
}
}
}
void FullyConnectedNN::evaluate(const Buffer<halnf>& input, Buffer<halnf>& output) {
ASSERT(output.size() == mLayers.last().mNeurons.size() && input.size() == mLayers.first().mNeurons.size())
ASSERT(output.size() == mLayers.last().neurons.size() && input.size() == mLayers.first().neurons.size())
for (auto idx : Range(input.size())) {
mLayers.first().mNeurons[idx].mActivationValue = input[idx];
mLayers.first().neurons[idx].activationValue = input[idx];
}
for (auto layerIdx : Range<halni>(1, (halni) mLayers.size())) {
auto& layer = mLayers[layerIdx];
auto& layerPrev = mLayers[layerIdx - 1];
for (auto neuron : layer.mNeurons) {
neuron->mActivationValue = 0;
for (auto connectionIdx : Range(neuron->mWeights.size())) {
neuron->mActivationValue += neuron->mWeights[connectionIdx] * layerPrev.mNeurons[connectionIdx].mActivationValue;
for (auto neuron : layer.neurons) {
neuron->activationValue = 0;
for (auto connectionIdx : Range(neuron->weights.size())) {
neuron->activationValue += neuron->weights[connectionIdx].val * layerPrev.neurons[connectionIdx].activationValue;
}
neuron->mActivationValue += neuron->mBias;
neuron->mActivationValueLinear = neuron->mActivationValue;
neuron->mActivationValue = relu(neuron->mActivationValue);
neuron->activationValue += neuron->bias.val;
neuron->activationValueLinear = neuron->activationValue;
neuron->activationValue = activationFunction(neuron->activationValue);
}
}
for (auto idx : Range(output.size())) {
output[idx] = mLayers.last().mNeurons[idx].mActivationValue;
output[idx] = mLayers.last().neurons[idx].activationValue;
}
}
halnf FullyConnectedNN::calcCost(const Buffer<halnf>& output) {
halnf out = 0;
for (auto neuronIdx : Range(mLayers.last().mNeurons.size())) {
out += pow(output[neuronIdx] - mLayers.last().mNeurons[neuronIdx].mActivationValue, 2);
for (auto neuronIdx : Range(mLayers.last().neurons.size())) {
out += pow(output[neuronIdx] - mLayers.last().neurons[neuronIdx].activationValue, 2);
}
return out;
}
void FullyConnectedNN::clearGrad() {
mLayersCache.reserve(mLayers.size());
for (auto layIdx : Range<halni>(0, (halni) mLayers.size())) {
mLayersCache[layIdx].mNeurons.reserve(mLayers[layIdx].mNeurons.size());
mLayersCache[layIdx].mCache = 1;
for (auto weightIdx : Range(mLayersCache[layIdx].mNeurons.size())) {
mLayersCache[layIdx].mNeurons[weightIdx].mBiasGrad = 0;
mLayersCache[layIdx].mNeurons[weightIdx].mWeightsGrad.reserve(mLayers[layIdx].mNeurons[weightIdx].mWeights.size());
for (auto weight : mLayersCache[layIdx].mNeurons[weightIdx].mWeightsGrad) {
weight.data() = 0;
}
}
}
mAvgCount = 0;
}
void FullyConnectedNN::calcGrad(const Buffer<halnf>& output) {
ASSERT(mLayers.last().mNeurons.size() == output.size())
ASSERT(mLayers.last().neurons.size() == output.size())
auto& lastLayer = mLayers.last();
auto& lastCache = mLayersCache.last();
lastCache.mCache = 1;
for (auto neuronIdx : Range(lastLayer.mNeurons.size())) {
auto& neuronCache = lastCache.mNeurons[neuronIdx];
auto& neuron = lastLayer.mNeurons[neuronIdx];
lastCache.mCache += 2 * pow(output[neuronIdx] - neuron.mActivationValue, 2);
// calculate chaining cache value for each neuron in last layer
for (auto neuronIdx : Range(lastLayer.neurons.size())) {
auto& neuron = lastLayer.neurons[neuronIdx];
neuron.cache = 2 * (neuron.activationValue - output[neuronIdx]);
}
// calculate rest of the layers
for (auto layerIdx = mLayers.size() - 1; layerIdx > 0; layerIdx--) {
auto& layer = mLayers[layerIdx];
auto& cache = mLayersCache[layerIdx];
auto& layerNext = mLayers[layerIdx - 1];
auto& cacheNext = mLayersCache[layerIdx - 1];
auto& currentLayer = mLayers[layerIdx];
auto& inputLayer = mLayers[layerIdx - 1];
cacheNext.mCache = 1;
for (auto currentNeuronIdx : Range(currentLayer.neurons.size())) {
auto& currentNeuron = currentLayer.neurons[currentNeuronIdx];
for (auto neuronIdx : Range(layer.mNeurons.size())) {
auto& neuron = layer.mNeurons[neuronIdx];
auto& neuronCache = cache.mNeurons[neuronIdx];
// calculate cache value (chaining)
if (layerIdx != mLayers.size() - 1) {
auto& userLayer = mLayers[layerIdx + 1];
auto tmp = cache.mCache * reluDerivative(neuron.mActivationValueLinear);
neuronCache.mBiasGrad = tmp;
for (auto weightIdx : Range(neuron.mWeights.size())) {
neuronCache.mWeightsGrad[weightIdx] = tmp * layerNext.mNeurons[weightIdx].mActivationValue;
currentNeuron.cache = 0;
for (auto userNeuron : userLayer.neurons) {
currentNeuron.cache += userNeuron->weights[currentNeuronIdx].val * userNeuron->cache;
}
currentNeuron.cache *= activationFunctionDerivative(currentNeuron.activationValueLinear);
}
cacheNext.mCache += tmp;
// gradient for current neuron bias
currentNeuron.bias.grad = currentNeuron.cache;
// calculate gradient for weights of current neuron
for (auto weightIdx : Range(currentNeuron.weights.size())) {
currentNeuron.weights[weightIdx].grad = inputLayer.neurons[weightIdx].activationValue * currentNeuron.cache;
}
}
}
mAvgCount++;
}
void FullyConnectedNN::applyGrad() {
void FullyConnectedNN::applyGrad(halnf step) {
for (auto layIdx : Range<halni>(1, (halni) mLayers.size())) {
auto& layerCache = mLayersCache[layIdx];
auto& layer = mLayers[layIdx];
for (auto neuronIdx : Range(layer.mNeurons.size())) {
auto& neuron = layer.mNeurons[neuronIdx];
auto& neuronCache = layerCache.mNeurons[neuronIdx];
neuron.mBias += neuronCache.mBiasGrad / (halnf) mAvgCount;
for (auto weightIdx : Range(neuron.mWeights.size())) {
neuron.mWeights[weightIdx] += neuronCache.mWeightsGrad[weightIdx] / (halnf) mAvgCount;
for (auto neuron : layer.neurons) {
neuron->bias.val -= neuron->bias.grad / (halnf) mAvgCount * step;
for (auto weightIdx : Range(neuron->weights.size())) {
neuron->weights[weightIdx].val -= (neuron->weights[weightIdx].grad / (halnf) mAvgCount) * step;
}
}
}
mAvgCount = 0;
}