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c-net/neuronal_network.c
2023-09-23 15:44:18 +02:00

233 lines
No EOL
7.3 KiB
C

#include <stdlib.h>
#include "neuronal_network.h"
#include <stdio.h>
#include <math.h>
double sigmoid(double input);
Matrix* predict(Neural_Network* network, Matrix* image_data);
double square(double input);
Matrix * backPropagation(double learning_rate, Matrix* weights, Matrix* biases, Matrix* current_layer_activation, Matrix* previous_layer_activation, Matrix* sigma_old);
Neural_Network* new_network(int input_size, int hidden_size, int hidden_amount, int output_size, double learning_rate){
Neural_Network* network = malloc(sizeof(Neural_Network));
network->input_size = input_size;
network->hidden_size = hidden_size;
network->hidden_amount = hidden_amount;
network->output_size = output_size;
network->learning_rate = learning_rate;
Matrix** weights = malloc(sizeof(Matrix*) * (hidden_amount + 1));
network->weights = weights;
network->weights[0] = matrix_create(hidden_size, input_size + 1);
for(int i=1;i<hidden_amount;i++){
network->weights[i] = matrix_create(hidden_size, hidden_size + 1);
}
network->weights[hidden_amount] = matrix_create(output_size, hidden_size + 1);
return network;
}
void randomize_network(Neural_Network* network, int scope){
for (int i = 0; i < network->hidden_amount + 1; i++) {
matrix_randomize(network->weights[i], scope);
}
}
void free_network(Neural_Network* network){
for (int i = 0; i < network->hidden_amount + 1; i++) {
matrix_free(network->weights[i]);
}
free(network->weights);
free(network);
}
void save_network(Neural_Network* network) {
char* file_name = "../networks/newest_network.txt";
// create file
FILE* save_file = fopen(file_name, "w");
// check if file is successfully opened
if(save_file == NULL) {
printf("ERROR: Something went wrong in file creation! (save_network)");
exit(1);
}
// save network size to first line of the file
fprintf(save_file, "%d\n", network->input_size);
fprintf(save_file, "%d\n", network->hidden_size);
fprintf(save_file, "%d\n", network->hidden_amount);
fprintf(save_file, "%d\n", network->output_size);
// close the file
fclose(save_file);
for (int i = 0; i < network->hidden_amount + 1; ++i) {
matrix_save(network->weights[i], file_name);
}
printf("Network Saved!");
}
Neural_Network* load_network(char* file) {
// create file pointer and open file
FILE* save_file = fopen(file, "r");
// check if file could be opened
if(save_file == NULL) {
printf("ERROR: File could not be opened/found! (load_network)");
exit(1);
}
// read & store the information on the size of the network from the save file
char buffer[MAX_BYTES];
fgets(buffer, MAX_BYTES, save_file);
int input_size = (int) strtol(buffer, NULL, 10);
fgets(buffer, MAX_BYTES, save_file);
int hidden_size = (int) strtol(buffer, NULL, 10);
fgets(buffer, MAX_BYTES, save_file);
int hidden_amount = (int) strtol(buffer, NULL, 10);
fgets(buffer, MAX_BYTES, save_file);
int output_size = (int) strtol(buffer, NULL, 10);
// create a new network to fill with the saved data
Neural_Network* saved_network = new_network(input_size, hidden_size, hidden_amount, output_size, 0);
for (int i = 0; i < saved_network->hidden_amount + 1; ++i) {
saved_network->weights[i] = load_next_matrix(save_file);
}
// return saved network
fclose(save_file);
return saved_network;
}
void print_network(Neural_Network* network) {
for (int i = 0; i < network->hidden_amount; ++i) {
matrix_print(network->weights[i]);
}
}
double measure_network_accuracy(Neural_Network* network, Image** images, int amount) {
int num_correct = 0;
for (int i = 0; i < amount; i++) {
Matrix* prediction = predict_image(network, images[i]);
if (matrix_argmax(prediction) == images[i]->label) {
num_correct++;
}
matrix_free(prediction);
}
return ((double) num_correct) / amount;
}
Matrix* predict_image(Neural_Network* network, Image* image){
Matrix* image_data = matrix_flatten(image->pixel_values, 0);
Matrix* res = predict(network, image_data);
matrix_free(image_data);
return res;
}
Matrix* predict(Neural_Network* network, Matrix* image_data) {
Matrix* input = matrix_add_bias(image_data);
Matrix* output[network->hidden_amount + 1];
for (int i = 0; i < network->hidden_amount + 1; ++i) {
Matrix* neuron_input = dot(network->weights[i], input);
Matrix* neuron_activation = apply(sigmoid, neuron_input);
output[i] = neuron_activation;
matrix_free(neuron_input);
matrix_free(input);
input = matrix_add_bias(neuron_activation);
}
for (int i = 0; i < network->hidden_amount; ++i) {
matrix_free(output[i]);
}
matrix_free(input);
return output[network->hidden_amount + 1];
}
void train_network(Neural_Network* network, Image *image, int label) {
Matrix* image_data = matrix_flatten(image->pixel_values, 0);
Matrix* input = matrix_add_bias(image_data);
Matrix* output[network->hidden_amount + 1];
for (int i = 0; i < network->hidden_amount + 1; ++i) {
Matrix* neuron_input = dot(network->weights[i], input);
Matrix* neuron_activation = apply(sigmoid, neuron_input);
output[i] = neuron_activation;
matrix_free(neuron_input);
matrix_free(input);
input = matrix_add_bias(neuron_activation);
}
// calculate the derivative of the sigmoid function of the input of the result layer
Matrix* ones = matrix_create(output[network->hidden_amount]->rows, output[network->hidden_amount]->columns);
matrix_fill(ones, 1);
Matrix* ones_minus_out = subtract(ones, output[network->hidden_amount]);
Matrix* sigmoid_derivative = multiply(output[network->hidden_amount], ones_minus_out);
// create wanted out-put matrix
Matrix* wanted_output = matrix_create(output[network->hidden_amount]->rows, output[network->hidden_amount]->columns);
matrix_fill(wanted_output, 0);
wanted_output->numbers[label][0] = 1;
// calculate difference to actual out-put
Matrix* error = subtract(wanted_output, output[network->hidden_amount]);
// calculate delta for output layer nodes
Matrix* delta = multiply(sigmoid_derivative, error);
//calculate the delta for all weights
Matrix* previous_out_with_one = matrix_add_bias(output[network->hidden_amount - 1]);
Matrix* transposed_previous_out_with_bias = transpose(previous_out_with_one);
Matrix* weights_delta_matrix = dot(delta, transposed_previous_out_with_bias);
// De-allocate stuff
matrix_free(image_data);
matrix_free(input);
for (int i = 0; i < network->hidden_amount + 1; ++i) {
matrix_free(output[i]);
}
matrix_free(ones);
matrix_free(sigmoid_derivative);
matrix_free(sigmoid_derivative);
matrix_free(wanted_output);
matrix_free(error);
matrix_free(delta);
matrix_free(previous_out_with_one);
matrix_free(weights_delta_matrix);
}
Matrix * backPropagation(double learning_rate, Matrix* weights, Matrix* biases, Matrix* current_layer_activation, Matrix* previous_layer_activation, Matrix* sigma_old) {
return NULL;
}
double sigmoid(double input) {
return 1.0 / (1 + exp(-1 * input));
}
double square(double input) {
return input * input;
}