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c-net/matrix.c
2023-09-24 22:36:40 +02:00

377 lines
No EOL
11 KiB
C

#include "matrix.h"
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <time.h>
#define MAX_BYTES 100
static int RANDOMIZED = 0;
// operational functions
Matrix* matrix_create(int rows, int columns) {
// allocate memory for the matrix
Matrix* matrix = malloc(sizeof(Matrix));
// set size variables to the correct size
matrix->rows = rows;
matrix->columns = columns;
// allocate memory for the numbers (2D-Array)
matrix->numbers = malloc(sizeof(double*) * rows);
for (int i = 0; i < rows; i++) {
matrix->numbers[i] = calloc(sizeof(double), columns);
}
// return the pointer to the allocated memory
return matrix;
}
void matrix_fill(Matrix* matrix, double value) {
// simple for loop to populate the 2D-array with a value
for (int i = 0; i < matrix->rows; i++) {
for (int j = 0; j < matrix->columns; j++) {
matrix->numbers[i][j] = value;
}
}
}
void matrix_free(Matrix* matrix) {
// de-allocate every column
for (int i = 0; i < matrix->rows; i++) {
free(matrix->numbers[i]);
}
// de-allocate the rows
free(matrix->numbers);
// de-allocate the matrix
free(matrix);
}
void matrix_print(Matrix *matrix) {
// print the dimensions of the matrix
printf("Rows: %d, Columns: %d\n", matrix->rows, matrix->columns);
// loop through all values and format them into the correct matrix representation
for (int i = 0; i < matrix->rows; i++) {
for (int j = 0; j < matrix->columns; j++) {
printf("%lf ", matrix->numbers[i][j]);
}
printf("\n");
}
}
Matrix* matrix_copy(Matrix *matrix) {
// create another matrix of the same size
Matrix* copy_of_matrix = matrix_create(matrix->rows, matrix->columns);
// copy the values from the original matrix into the copy
for (int i = 0; i < matrix->rows; i++) {
for (int j = 0; j < matrix->columns; j++) {
copy_of_matrix->numbers[i][j] = matrix->numbers[i][j];
}
}
// return the pointer to the copy
return copy_of_matrix;
}
// mathematical functions
/*
* These methods won't change or free the input matrix.
* It creates a new matrix, which is modified and then returned.
* If we don't need the original matrix, we should consider just changing the original matrix and changing the method signature to void.
*/
Matrix* multiply(Matrix* matrix1, Matrix* matrix2) {
// check if the two matrices are of the same size
if(matrix1->rows != matrix2->rows || matrix1->columns != matrix2->columns) {
printf("ERROR: Size of matrices are not compatible! (Multiply)");
exit(1);
}
// create result matrix
Matrix* result_matrix = matrix_create(matrix1->rows, matrix1->columns);
// multiply the values and save them into the result matrix
for (int i = 0; i < matrix1->rows; i++) {
for (int j = 0; j < matrix1->columns; j++) {
result_matrix->numbers[i][j] = matrix1->numbers[i][j] * matrix2->numbers[i][j];
}
}
// return resulting matrix
return result_matrix;
}
Matrix* add(Matrix* matrix1, Matrix* matrix2) {
// check if the two matrices are of the same size
if(matrix1->rows != matrix2->rows || matrix1->columns != matrix2->columns) {
printf("ERROR: Size of matrices are not compatible! (Add)");
exit(1);
}
// create result matrix
Matrix* result_matrix = matrix_create(matrix1->rows, matrix1->columns);
// add the value of the number in matrix 1 to the value of the number in matrix 2
for (int i = 0; i < matrix1->rows; i++) {
for (int j = 0; j < matrix1->columns; j++) {
result_matrix->numbers[i][j] = matrix1->numbers[i][j] + matrix2->numbers[i][j];
}
}
// return the result matrix
return result_matrix;
}
Matrix* subtract(Matrix* matrix1, Matrix* matrix2) {
// check if the two matrices are of the same size
if(matrix1->rows != matrix2->rows || matrix1->columns != matrix2->columns) {
printf("ERROR: Size of matrices are not compatible! (Subtract)");
exit(1);
}
// create result matrix
Matrix* result_matrix = matrix_create(matrix1->rows, matrix1->columns);
// subtract the value of the number in matrix 2 from the value of the number in matrix 1
for (int i = 0; i < matrix1->rows; i++) {
for (int j = 0; j < matrix1->columns; j++) {
result_matrix->numbers[i][j] = matrix1->numbers[i][j] - matrix2->numbers[i][j];
}
}
// return the resulting matrix
return result_matrix;
}
Matrix* dot(Matrix* matrix1, Matrix* matrix2) {
// check if the dimensions of the matrices are compatible to calculate the dot product
if(matrix1->columns != matrix2->rows) {
printf("ERROR: Size of matrices are not compatible! (Dot-Product)");
exit(1);
}
// create a new matrix with the dimensions of the dot product;
Matrix* result_matrix = matrix_create(matrix1->rows, matrix2->columns);
// iterate through all rows of matrix 1
for (int i = 0; i < matrix1->rows; i++) {
// iterate though all columns of matrix 2
for (int j = 0; j < matrix2->columns; j++) {
// sum up the products and save them into the result matrix
result_matrix->numbers[i][j] = 0;
for (int k = 0; k < matrix2->rows; k++) {
result_matrix->numbers[i][j] += matrix1->numbers[i][k] * matrix2->numbers[k][j];
}
}
}
// return result
return result_matrix;
}
Matrix* apply(double (*function)(double), Matrix* matrix) {
// create a new matrix used to calculate the result
Matrix* result_matrix = matrix_create(matrix->rows, matrix->columns);
// apply the function to all values in the matrix
for (int i = 0; i < matrix->rows; i++) {
for (int j = 0; j < matrix->columns; j++) {
result_matrix->numbers[i][j] = (*function)(matrix->numbers[i][j]);
int k = 0;
}
}
// return resulting matrix
return result_matrix;
}
Matrix* scale(Matrix* matrix, double value) {
// create a copy of the original matrix
Matrix* result_matrix = matrix_copy(matrix);
// iterate over all numbers in the matrix and multiply by the scalar value
for (int i = 0; i < result_matrix->rows; i++) {
for (int j = 0; j < result_matrix->columns; j++) {
result_matrix->numbers[i][j] *= value;
}
}
// return the copy
return result_matrix;
}
Matrix* transpose(Matrix* matrix) {
// create a new matrix of the size n-m, based on the original matrix of size m-n
Matrix* result_matrix = matrix_create(matrix->columns, matrix->rows);
// copy the values from the original into the correct place in the copy
for (int i = 0; i < matrix->rows; i++) {
for (int j = 0; j < matrix->columns; j++) {
result_matrix->numbers[j][i] = matrix->numbers[i][j];
}
}
// return the result matrix
return result_matrix;
}
void matrix_save(Matrix* matrix, char* file_string){
// open the file in append mode
FILE *file = fopen(file_string, "a");
// check if the file could be found
if(file == NULL) {
printf("ERROR: Unable to get handle for \"%s\"! (matrix_save)", file_string);
exit(1);
}
// save the size of the matrix
fprintf(file, "%d\n", matrix->rows);
fprintf(file, "%d\n", matrix->columns);
// save all the numbers of the matrix into the file
for(int i = 0; i < matrix->rows; i++){
for(int j = 0; j < matrix->columns; j++){
fprintf(file, "%.10f\n", matrix->numbers[i][j]);
}
}
// close the file
fclose(file);
}
Matrix* matrix_load(char* file_string){
FILE *fptr = fopen(file_string, "r");
if(!fptr){
printf("Could not open \"%s\"", file_string);
exit(1);
}
Matrix * m = load_next_matrix(fptr);
fclose(fptr);
return m;
}
Matrix* load_next_matrix(FILE *save_file){
char buffer[MAX_BYTES];
fgets(buffer, MAX_BYTES, save_file);
int rows = (int)strtol(buffer, NULL, 10);
fgets(buffer, MAX_BYTES, save_file);
int cols = (int)strtol(buffer, NULL, 10);
Matrix *matrix = matrix_create(rows, cols);
for(int i = 0; i < rows; i++){
for(int j = 0; j < cols; j++){
fgets(buffer, MAX_BYTES, save_file);
matrix->numbers[i][j] = strtod(buffer, NULL);
}
}
return matrix;
}
Matrix* matrix_flatten(Matrix* matrix, int axis) {
// Axis = 0 -> Column Vector, Axis = 1 -> Row Vector
Matrix* result_matrix;
// Column Vector
if (axis == 0) {
result_matrix = matrix_create(matrix -> rows * matrix -> columns, 1);
}
// Row Vector
else if (axis == 1) {
result_matrix = matrix_create(1, matrix -> rows * matrix -> columns);
} else {
printf("ERROR: Argument must be 1 or 0 (matrix_flatten)");
exit(EXIT_FAILURE);
}
for (int i = 0; i < matrix->rows; i++) {
for (int j = 0; j < matrix->columns; j++) {
if (axis == 0) result_matrix->numbers[i * matrix->columns + j][0] = matrix->numbers[i][j];
else if (axis == 1) result_matrix->numbers[0][i * matrix->columns + j] = matrix->numbers[i][j];
}
}
return result_matrix;
}
int matrix_argmax(Matrix* matrix) {
// Expects a Mx1 matrix
if (matrix->columns != 1){
printf("ERROR: Matrix is not Mx1 (matrix_argmax)");
exit(EXIT_FAILURE);
}
double max_value = 0;
int max_index = 0;
for (int i = 0; i < matrix->rows; i++) {
if (matrix->numbers[i][0] > max_value) {
max_value = matrix->numbers[i][0];
max_index = i;
}
}
return max_index;
}
void matrix_randomize(Matrix* matrix, int n) {
if(!RANDOMIZED){
srand(time(NULL));
RANDOMIZED = 1;
}
//make a min and max
double min = -1.0f / sqrt(n);
double max = 1.0f / sqrt(n);
//calculate difference
double difference = max - min;
//move decimal
int scaled_difference = (int)(difference * scaling_value);
for (int i = 0; i < matrix->rows; i++) {
for (int j = 0; j < matrix->columns; j++) {
matrix->numbers[i][j] = min + (1.0 * (rand() % scaled_difference) / scaling_value);
}
}
}
Matrix* matrix_add_bias(Matrix* matrix) {
if(matrix->columns != 1) {
printf("ERROR: The size of the matrix does not match an input matrix! (matrix_add_bias)");
exit(1);
}
Matrix* result = matrix_create(matrix->rows + 1, matrix->columns);
result->numbers[0][0] = 1.0;
for (int i = 0; i < matrix->rows; ++i) {
result->numbers[i + 1][0] = matrix->numbers[i][0];
}
return result;
}