/**
* Set a block in this matrix equal to the given matrix
*
* @param i the top row of the block
* @param j the left most column of the block
* @param matrix the values to set the block with
*/
public void set(int i, int j, Matrix matrix) {
for (int row = i; row < matrix.m() + i; row++) {
for (int column = j; column < matrix.n() + j; column++) {
set(row, column, matrix.get(row - i, column - j));
}
}
}
/**
* Subtract from this matrix in place
*
* @param matrix the matrix to subtract
*/
public void minusEquals(Matrix matrix) {
for (int i = 0; i < m(); i++) {
for (int j = 0; j < n(); j++) {
set(i, j, get(i, j) - matrix.get(i, j));
}
}
}
/**
* Subtract this matrix with another matrix
*
* @param matrix the other matrix
* @return the resulting matrix
*/
public Matrix minus(Matrix matrix) {
double[][] result = new double[m()][n()];
for (int i = 0; i < result.length; i++) {
for (int j = 0; j < result[i].length; j++) {
result[i][j] = get(i, j) - matrix.get(i, j);
}
}
return new RectangularMatrix(result);
}
/**
* Multiply this matrix with another matrix
*
* @param matrix the other matrix
* @return the resulting matrix
*/
public Matrix times(Matrix matrix) {
double[][] result = new double[m()][matrix.n()];
for (int row = 0; row < result.length; row++) {
for (int column = 0; column < result[0].length; column++) {
for (int i = 0; i < n(); i++) {
result[row][column] += get(row, i) * matrix.get(i, column);
}
}
}
return new RectangularMatrix(result);
}