int Matrix_isIdentity(Matrix *m){
int i,j,rows=m->rows,cols=m->cols;
for (i=0;i<rows;i++){
for (j=0;j<cols;j++){
if(i==j && Matrix_get(m,i,j)!=1) return(0);
if(i!=j && Matrix_get(m,i,j)!=0) return(0);
}
}
return(1);
}
Matrix *Matrix_product(Matrix *m1, Matrix *m2){
int i,j,y;
Matrix *c=Matrix_create(m1->rows,m1->cols);
for(i =0;i<m1->rows; i++){
for(j=0;j<m2->cols; j++){
for(y=0;y<m1->cols; y++){
Matrix_set(c,i,j,Matrix_get(c,i,j) + Matrix_get(m1,i,y) * Matrix_get(m2,y,j));
}
}
}
return(c);
}
Matrix *Matrix_inverse(Matrix *mat){
double det=Matrix_determinant(mat);
if(mat->rows != mat->cols || det == 0.0){
return Matrix_create(mat->rows, mat->cols);
}
Matrix *temp = Matrix_clone(mat);
int n = temp->rows;
int m = temp->cols;
int i,j;
double tempdet,val;
Matrix *Cofactor = Matrix_create(n, m);
for(j = 0; j < m; j++){
for(i = 0; i < n; i++){
Matrix *Mintemp = Matrix_minor(temp,i, j);
tempdet = Matrix_determinant(Mintemp);
Matrix_set(Cofactor,i,j,tempdet);
}
}
Cofactor = Matrix_transpose(Cofactor);
for(i = 0; i < n; i++){
for(j = 0; j < m; j++){
val=Matrix_get(Cofactor,i,j) * pow(-1.0,(i+j)) /det;
if(isnan(val)) val=0;
Matrix_set(Cofactor,i,j, val);
//Cofactor.setValue(i, j, (Cofactor.getValue(i, j) * Math.pow(-1D, i + j + 2)) / det);
}
}
return Cofactor;
}
Matrix* Matrix_minor(Matrix *mat, int x, int y){
Matrix *temp = Matrix_clone(mat);
Matrix *newmat = Matrix_create(temp->rows - 1, temp->cols - 1);
int i,j;
int n = temp->rows;
int m = temp->cols;
int cnt = 0;
double *myArr = (double*)malloc((n - 1) * (m - 1) * sizeof(double));
for(i = 0; i < n; i++){
for(j = 0; j < m; j++){
if(i != x && j != y){
myArr[cnt] = Matrix_get(temp,i,j);
cnt++;
}
}
}
cnt = 0;
for(i = 0; i < n - 1; i++){
for(j = 0; j < m - 1; j++){
Matrix_set(newmat,i,j,myArr[cnt]);
cnt++;
}
}
return newmat;
}
Matrix *Matrix_echelon(Matrix* m){
int cols=m->cols;
int rows=m->rows;
int i=0,j=0,k=0;
Matrix *temp=Matrix_clone(m);
double pivot;
for (i=0;i<rows;i++){
for(j = i + 1;j<rows;j++){
pivot = -1*Matrix_get(temp,j,i) / Matrix_get(temp,i,i);
for(k = 0; k < cols; k++){
Matrix_set(temp,j,k, Matrix_get(temp,i,k) * pivot + Matrix_get(temp,j,k));
}
}
}
return(temp);
}
double Matrix_determinant(Matrix *m){
Matrix *temp=Matrix_echelon(m);
int i;
double sum=1.0;
for (i=0;i<m->rows;i++) {
sum*=Matrix_get(temp,i,i);
}
return(sum);
}
Matrix *Matrix_transpose(Matrix *m){
Matrix *newmatrix=Matrix_create(m->cols, m->rows);
int i,j;
for (i=0;i<m->rows;i++){
for (j=0;j<m->cols;j++){
Matrix_set(newmatrix,j,i,Matrix_get(m,i,j));
}
}
return(newmatrix);
}
/***Matrix_delete***/
Token Matrix_delete(Token token, ...) {
int i, j;
Token element, emptyToken;
// Delete each elements.
for (i = 0; i < token.payload.Matrix->column; i++) {
for (j = 0; j < token.payload.Matrix->row; j++) {
element = Matrix_get(token, j, i);
functionTable[(int) element.type][FUNC_delete](element);
}
}
free(token.payload.Matrix->elements);
free(token.payload.Matrix);
return emptyToken;
}
// make a new matrix from the given values
// assume that number of the rest of the arguments == length,
// and they are in the form of (element, element, ...).
// The rest of the arguments should be of type Token *.
Token Matrix_new(int row, int column, int given, ...) {
va_list argp;
int i;
Token result;
char elementType;
result.type = TYPE_Matrix;
result.payload.Matrix = (MatrixToken) malloc(sizeof(struct matrix));
result.payload.Matrix->row = row;
result.payload.Matrix->column = column;
// Allocate a new matrix of Tokens.
if (row > 0 && column > 0) {
// Allocate an new 2-D array of Tokens.
result.payload.Matrix->elements = (Token*) calloc(row * column, sizeof(Token));
if (given > 0) {
// Set the first element.
va_start(argp, given);
for (i = 0; i < given; i++) {
result.payload.Matrix->elements[i] = va_arg(argp, Token);
}
// elementType is given as the last argument.
elementType = va_arg(argp, int);
if (elementType >= 0) {
// convert the elements if needed.
for (i = 0; i < given; i++) {
if (Matrix_get(result, i, 0).type != elementType) {
result.payload.Matrix->elements[i] = functionTable[(int)elementType][FUNC_convert](Matrix_get(result, i, 0));
}
}
}
va_end(argp);
}
