public Matrix matrixReverse() { // 求矩阵的逆
int i, j, k;
double change;
Matrix matrix_reverse = new Matrix(this);
for (i = 0; i < matrix_reverse.getLine(); i++)
for (j = matrix_reverse.getRow(); j < 2 * matrix_reverse.getRow(); j++)
matrix_reverse.setElement(i, j, (j == matrix_reverse.getRow() + i) ? 1 : 0);
matrix_reverse.setRow(2 * matrix_reverse.getRow());
matrix_reverse = matrix_reverse.matrixLineSimplify();
/*将矩阵的左半边化为单位阵*/
for (i = 0; i < matrix_reverse.getLine() - 1; i++)
for (j = i + 1; j < matrix_reverse.getRow() / 2; j++) {
if (matrix_reverse.getElement(i, j) == 0) continue;
if (matrix_reverse.getElement(i, j) < 0)
for (k = 0; k < matrix_reverse.getRow(); k++)
matrix_reverse.setElement(i, k, -matrix_reverse.getElement(i, k));
if (matrix_reverse.getElement(j, j) < 0)
for (k = 0; k < matrix_reverse.getRow(); k++)
matrix_reverse.setElement(j, k, -matrix_reverse.getElement(j, k));
change = matrix_reverse.getElement(i, j) / matrix_reverse.getElement(j, j);
for (k = 0; k < matrix_reverse.getRow(); k++)
matrix_reverse.setElement(
i, k, matrix_reverse.getElement(i, k) - matrix_reverse.getElement(j, k) * change);
}
matrix_reverse.setRow(matrix_reverse.getRow() / 2);
for (i = 0; i < matrix_reverse.getLine(); i++)
for (j = 0; j < matrix_reverse.getRow(); j++)
matrix_reverse.setElement(i, j, matrix_reverse.getElement(i, j + matrix_reverse.getRow()));
return matrix_reverse;
}
public Matrix matrixTranspose() { // 矩阵转置
int i, j;
Matrix trans_matrix = new Matrix();
for (i = 0; i < getLine(); i++)
for (j = 0; j < getRow(); j++) trans_matrix.setElement(j, i, this.getElement(i, j));
trans_matrix.setLine(getLine());
trans_matrix.setRow(getRow());
trans_matrix.setAccuracy(getAccuracy());
return trans_matrix;
}
public static Matrix matrixMinus(Matrix matrix1, Matrix matrix2) { // 矩阵减法
int i, j;
Matrix matrix = new Matrix();
for (i = 0; i < matrix1.getLine(); i++)
for (j = 0; j < matrix1.getRow(); j++)
matrix.setElement(i, j, matrix1.getElement(i, j) - matrix2.getElement(i, j));
matrix.setLine(matrix1.getLine());
matrix.setRow(matrix1.getRow());
matrix.setAccuracy(matrix1.getAccuracy());
return matrix;
}
public static Matrix matrixCopy(Matrix matrix) { // 矩阵复制
int i, j;
Matrix matrix_copy = new Matrix();
matrix_copy.setLine(matrix.getLine());
matrix_copy.setRow(matrix.getRow());
matrix_copy.setAccuracy(matrix.getAccuracy());
matrix_copy.setName(matrix.getName());
for (i = 0; i < matrix.getLine(); i++)
for (j = 0; j < matrix.getRow(); j++) matrix_copy.setMatrixArray(matrix.getMatrixArray());
return matrix_copy;
}
public static Matrix scanMatrix() { // 输入矩阵
int i, j;
Matrix matrix = new Matrix();
Scanner scanner = new Scanner(System.in);
matrix.setLine(scanner.nextInt());
matrix.setRow(scanner.nextInt());
matrix.setAccuracy(scanner.nextDouble());
for (i = 0; i < matrix.getLine(); i++) {
for (j = 0; j < matrix.getRow(); j++) matrix.setElement(i, j, scanner.nextDouble());
}
return matrix;
}
public static Matrix matrixMultiply(Matrix matrix1, Matrix matrix2) { // 矩阵乘法
int i, j, k;
Matrix matrix = new Matrix();
matrix.setLine(matrix1.getLine());
matrix.setRow(matrix2.getRow());
matrix.setAccuracy(matrix1.getAccuracy());
for (i = 0; i < matrix.getLine(); i++)
for (j = 0; j < matrix.getRow(); j++) matrix.setElement(i, j, 0.0);
for (i = 0; i < matrix.getLine(); i++)
for (j = 0; j < matrix.getRow(); j++)
for (k = 0; k < matrix1.getRow(); k++)
matrix.setElement(
i, j, matrix.getElement(i, j) + matrix1.getElement(i, k) * matrix2.getElement(k, j));
return matrix;
}