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 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 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;
}
public Matrix matrixNumMultiply(double x) { // 矩阵乘以一个数
int i, j;
Matrix matrix = new Matrix(this);
for (i = 0; i < matrix.getLine(); i++)
for (j = 0; j < matrix.getRow(); j++) matrix.setElement(i, j, x * matrix.getElement(i, j));
return matrix;
}
public Matrix matrixAccuralize() { // 精确化矩阵
int i, j;
Matrix matrix = new Matrix(this);
for (i = 0; i < matrix.getLine(); i++)
for (j = 0; j < matrix.getRow(); j++)
if (Math.abs(matrix.getElement(i, j)) <= matrix.getAccuracy()) matrix.setElement(i, j, 0.0);
return matrix;
}
public static void matrixToPanel(JTextField[] jtfMatrix, Matrix matrix) {
int i, j;
DecimalFormat df = new DecimalFormat(String.valueOf(matrix.getAccuracy()).replace('1', '0'));
for (i = 0; i < matrix.getLine(); i++)
for (j = 0; j < matrix.getRow(); j++) {
jtfMatrix[i * matrix.getRow() + j].setText(
String.valueOf(df.format(matrix.getElement(i, j))));
}
}
public int matrixRank() // 矩阵的秩
{
int rank = 0, i, j;
Matrix matrix = new Matrix();
matrix = matrixLineSimplify();
for (i = 0; i < matrix.getLine(); i++)
for (j = 0; j < matrix.getRow(); j++)
if (Math.abs(matrix.getElement(i, j)) > matrix.getAccuracy()) {
rank++;
break;
}
return rank;
}
public double determinantValue() // 计算行列式
{
int i, j, k, p = 0;
double change, value = 1.0;
Matrix matrix = new Matrix(this);
for (i = 0; i < matrix.getLine(); i++) {
for (j = i + 1; j < matrix.getLine(); j++)
for (; p < matrix.getLine(); p++) {
if (matrix.getElement(i, p) == 0 && matrix.getElement(j, p) != 0)
for (k = p; k < matrix.getRow(); k++)
matrix.setElement(i, k, matrix.getElement(i, k) + matrix.getElement(j, k));
else if (matrix.getElement(i, p) == 0 && matrix.getElement(j, p) == 0) {
for (; j < matrix.getLine() && matrix.getElement(j, p) == 0; j++) ;
if (j == matrix.getLine()) {
j = i + 1;
continue;
} else {
for (k = p; k < matrix.getRow(); k++)
matrix.setElement(i, k, matrix.getElement(i, k) + matrix.getElement(j, k));
}
} else if (matrix.getElement(i, p) != 0 && matrix.getElement(j, p) == 0) break;
change = matrix.getElement(j, p) / matrix.getElement(i, p);
for (k = p; k < matrix.getRow(); k++)
matrix.setElement(j, k, matrix.getElement(j, k) - matrix.getElement(i, k) * change);
break;
}
p = i;
}
for (i = 0; i < matrix.getLine(); i++) value *= matrix.getElement(i, i);
return value;
}
public Matrix matrixLineSimplify() { // 矩阵的行简化
int i, j, k, p = 0;
double change, first_of_line;
Matrix matrix0 = new Matrix(this);
for (i = 0; i < matrix0.getLine(); i++) {
for (j = i + 1; j < matrix0.getLine(); j++)
for (; p < matrix0.getRow(); p++) {
if (matrix0.getElement(i, p) == 0 && matrix0.getElement(j, p) != 0)
for (k = 0; k < matrix0.getRow(); k++)
matrix0.setElement(i, k, matrix0.getElement(i, k) + matrix0.getElement(j, k));
else if (matrix0.getElement(i, p) == 0 && matrix0.getElement(j, p) == 0) {
for (; j < matrix0.getLine() && matrix0.getElement(j, p) == 0; j++) ;
if (j == matrix0.getLine()) {
j = i + 1;
continue;
} else {
for (k = p; k < matrix0.getRow(); k++)
matrix0.setElement(i, k, matrix0.getElement(i, k) + matrix0.getElement(j, k));
}
} else if (matrix0.getElement(i, p) != 0 && matrix0.getElement(j, p) == 0) break;
if (matrix0.getElement(i, p) < 0)
for (k = p; k < matrix0.getRow(); k++)
matrix0.setElement(i, k, -matrix0.getElement(i, k));
if (matrix0.getElement(j, p) < 0)
for (k = p; k < matrix0.getRow(); k++)
matrix0.setElement(j, k, -matrix0.getElement(j, k));
change = matrix0.getElement(j, p) / matrix0.getElement(i, p);
for (k = p; k < matrix0.getRow(); k++)
matrix0.setElement(j, k, matrix0.getElement(j, k) - matrix0.getElement(i, k) * change);
break;
}
p = i;
}
// 将每一行最简化
matrix0 = matrix0.matrixAccuralize();
for (i = 0; i < matrix0.getLine(); i++) {
for (j = 0; j < matrix0.getRow() && matrix0.getElement(i, j) == 0; j++) ;
first_of_line = matrix0.getElement(i, j);
if (j == matrix0.getRow()) continue;
for (; j < matrix0.getRow(); j++)
matrix0.setElement(i, j, matrix0.getElement(i, j) / first_of_line);
}
return matrix0;
}