最近因为一些原因重新回到了java的怀抱，作为自己的第一个自学的纯面向对象的语言，对它的感情其实还是蛮深的，最近又在课上听到老师说过一个关于矩阵求逆的小程序，自己一时手热边用java完成了关于矩阵的功能。
首先说矩阵，相信很多工科的同胞们都被其饱受折磨。可它的应用范围极广我们也不得不学，总之又爱又恨。关于矩阵类的实现，绝大多数C++程序员是用数组和指针实现的，大部分java工程师也是用数组实现的。而且我在网上搜过相关的博文，大部分人都只完成了int型一种矩阵，笔者这次在JAVA的Vector的前提下完成了int,float,double三种类型的矩阵，也算是对java的容器和数据类型及运算做了一个总结，说实话java确实不适合数据运算，它不支持运算符重载的缺陷型让一些数据计算变得很繁琐。有兴趣的笔友们可以在python或者C++的基础上完成矩阵类的编写。
一，如何实现矩阵类
public Vector data;
public final static int MAT_INT = 1;
public final static int MAT_FLOAT = 2;
public final static int MAT_DOUBLE = 3;
public int MAT_TYPE = 1;
public int rows;
public int cols;从上面我们可以看到，笔者定义了一个存放矩阵数据的容器，三种矩阵类型参数，分别代表了int,float,double以及代表矩阵类型的MAT_TYPE，我们默认矩阵是int型的，毕竟这种类型最多。另外还有矩阵的大小参数rows,cols即矩阵的行数，列数。
/**
* @param rows 矩阵的行数，相当于y坐标
* @param cols 矩阵的列数，相当如x坐标
* @param type 矩阵的类型，int,float,double三种
*/
public Mat(int rows, int cols, int type) {
this.rows = rows;
this.cols = cols;
switch (type) {
case MAT_INT:
int zerosi = 0;
data = new Vector<Vector>(rows);
for (int i = 0; i < rows; i++) {
Vector v = new Vector<Integer>(cols);
for (int j = 0; j < cols; j++) {
v.add(j, zerosi);
}
data.add(i, v);
}
break;
case MAT_FLOAT:
float zerosf = 0;
this.MAT_TYPE = 2;
data = new Vector<Vector>(rows);
for (int i = 0; i < rows; i++) {
Vector v = new Vector<Float>(cols);
for (int j = 0; j < cols; j++) {
v.add(j, zerosf);
}
data.add(i, v);
}
break;
case MAT_DOUBLE:
this.MAT_TYPE = 3;
float zerosd = 0;
data = new Vector<Vector>(rows);
for (int i = 0; i < rows; i++) {
Vector v = new Vector<Double>(cols);
for (int j = 0; j < cols; j++) {
v.add(j, zerosd);
}
data.add(i, v);
}
break;
default:
break;
}
}
public Mat(int rows, int cols) {
this.rows = rows;
this.cols = cols;
int zeros = 0;
data = new Vector<Vector>(rows);
for (int i = 0; i < rows; i++) {
Vector v = new Vector<Integer>(cols);
for (int j = 0; j < cols; j++) {
v.add(j, zeros);
}
data.add(i, v);
}
}
public Mat() {
this(5, 5);
}
/**
* @param num 以数组的方式来构造矩阵
*/
public Mat(int num[][]) {
this.rows = num.length;
this.cols = num[0].length;
this.MAT_TYPE = MAT_INT;
data = new Vector<Vector>(rows);
for (int i = 0; i < rows; i++) {
Vector v = new Vector<Integer>(cols);
for (int j = 0; j < cols; j++) {
v.add(j, num[i][j]);
}
data.add(i, v);
}
}
public Mat(float num[][]) {
this.rows = num.length;
this.cols = num[0].length;
this.MAT_TYPE = MAT_FLOAT;
data = new Vector<Vector>(rows);
for (int i = 0; i < rows; i++) {
Vector v = new Vector<Float>(cols);
for (int j = 0; j < cols; j++) {
v.add(j, num[i][j]);
}
data.add(i, v);
}
}
public Mat(double num[][]) {
this.rows = num.length;
this.cols = num[0].length;
this.MAT_TYPE = MAT_DOUBLE;
data = new Vector<Vector>(rows);
for (int i = 0; i < rows; i++) {
Vector v = new Vector<Double>(cols);
for (int j = 0; j < cols; j++) {
v.add(j, num[i][j]);
}
data.add(i, v);
}
}笔者定义了很多的Mat类的构造函数，包括默认的int型初始化和指定类型的初始化和相应的数组初始化。
/**
* 输出矩阵中的内容
*/
public void print() {
System.out.println("[");
for (int i = 0; i < rows; i++) {
Vector v = (Vector) data.get(i);
for (int j = 0; j < cols; j++) {
System.out.print(v.get(j) + ",");
}
System.out.println();
}
System.out.println("]");
}
/**
* 将矩阵中的元素全部置0
*/
public void zeros() {
if (MAT_TYPE == MAT_INT) {
int zerosi = 0;
for (int i = 0; i < rows; i++) {
Vector v = (Vector) data.get(i);
for (int j = 0; j < cols; j++) {
v.set(j, zerosi);
}
data.set(i, v);
}
} else if (MAT_TYPE == MAT_FLOAT) {
float zerosf = 0;
for (int i = 0; i < rows; i++) {
Vector v = (Vector) data.get(i);
for (int j = 0; j < cols; j++) {
v.set(j, zerosf);
}
data.set(i, v);
}
} else {
for (int i = 0; i < rows; i++) {
double zerosd = 0;
Vector v = (Vector) data.get(i);
for (int j = 0; j < cols; j++) {
v.set(j, zerosd);
}
data.set(i, v);
}
}
}
/**
* 将矩阵中的元素全部置1
*/
public void ones() {
if (MAT_TYPE == MAT_INT) {
int onesi = 1;
for (int x = 0; x < rows; x++) {
Vector v = (Vector) data.get(x);
for (int y = 0; y < cols; y++) {
v.set(y, onesi);
}
data.set(x, v);
}
} else if (MAT_TYPE == MAT_FLOAT) {
float onesf = 1;
for (int i = 0; i < rows; i++) {
Vector v = (Vector) data.get(i);
for (int j = 0; j < cols; j++) {
v.set(j, onesf);
}
data.set(i, v);
}
} else {
for (int i = 0; i < rows; i++) {
double onesd = 1;
Vector v = (Vector) data.get(i);
for (int j = 0; j < cols; j++) {
v.set(j, onesd);
}
data.set(i, v);
}
}
}上面我们还可以看到笔者定义了三个很有用的成员函数，print()输出矩阵的内容，zeros()将矩阵数据全部置0，ones将矩阵的数据全部置1。
接下来便是我们矩阵类的核心函数了：
/**
* 矩阵转置
*/
public void T() {
if (MAT_TYPE == MAT_INT) {
Vector t = new Vector<Vector>(cols);
for (int i = 0; i < cols; i++) {
Vector v = new Vector<Integer>(rows);
for (int j = 0; j < rows; j++) {
Vector oldc = (Vector) data.get(j);
v.add(j, oldc.get(i));
}
t.add(i, v);
}
data = t;
int tmp = this.rows;
this.rows = this.cols;
this.cols = tmp;
} else if (MAT_TYPE == MAT_FLOAT) {
Vector t = new Vector<Vector>(cols);
for (int i = 0; i < cols; i++) {
Vector v = new Vector<Float>(rows);
for (int j = 0; j < rows; j++) {
Vector oldc = (Vector) data.get(j);
v.add(j, oldc.get(i));
}
t.add(i, v);
}
data = t;
int tmp = this.rows;
this.rows = this.cols;
this.cols = tmp;
} else {
Vector t = new Vector<Vector>(cols);
for (int i = 0; i < cols; i++) {
Vector v = new Vector<Double>(rows);
for (int j = 0; j < rows; j++) {
Vector oldc = (Vector) data.get(j);
v.add(j, oldc.get(i));
}
t.add(i, v);
}
data = t;
int tmp = this.rows;
this.rows = this.cols;
this.cols = tmp;
}
}
/**
* 设置矩阵中某个坐标的元素内容
*
* @param rowindex y坐标
* @param colindex x坐标
* @param num 要输入的内容
*/
public void Set(int rowindex, int colindex, Object num) {
Vector oldc = (Vector) data.get(rowindex);
if (MAT_TYPE == MAT_INT) {
int score = Integer.parseInt(num.toString());
oldc.set(colindex, score);
} else if (MAT_TYPE == MAT_FLOAT) {
float score = Float.parseFloat(num.toString());
oldc.set(colindex, score);
} else {
double score = Double.parseDouble(num.toString());
oldc.set(colindex, score);
}
}
/**
* 得到矩阵中某个坐标元素的内容
*
* @param rowindex y坐标
* @param colindex x坐标
* @return 返回一个object类型
*/
public Object Get(int rowindex, int colindex) {
Vector oldc = (Vector) data.get(rowindex);
return oldc.get(colindex);
}
/**
* 矩阵行列式求值
*
* @param num 矩阵的数据，以数组输入
* @param n 矩阵的行列数
* @return 返回行列式的值
*/
public int getvalue(int num[][], int n) {
int value = 0;
if (n == 1) return num[0][0];
int temp[][] = new int[n - 1][n - 1];
for (int i = 0; i < n; i++) {
for (int j = 0; j < n - 1; j++) {
for (int k = 0; k < n - 1; k++) {
int flag;
if (j < i) flag = 0;
else flag = 1;
temp[j][k] = num[j + flag][k + 1];
}
}
int flag2 = -1;
if (i % 2 == 0) flag2 = 1;
value += flag2 * num[i][0] * getvalue(temp, n - 1);
}
return value;
}
/**
* 矩阵行列式求值
*
* @return
*/
public int dot() {
if (MAT_TYPE != MAT_INT || rows != cols) {
return -1;
}
int value[][] = new int[rows][cols];
for (int i = 0; i < rows; i++) {
for (int j = 0; j < cols; j++) {
Object o = Get(i, j);
value[i][j] = Integer.parseInt(o.toString());
}
}
int fianl = getvalue(value, rows);
return fianl;
}
/**
* 矩阵相加
*
* @param m1 矩阵1
* @param m2 矩阵2
* @return 返回相加的矩阵
*/
public static Mat add(Mat m1, Mat m2) {
int outtype = 1;
if (m1.MAT_TYPE >= m2.MAT_TYPE) {
outtype = m1.MAT_TYPE;
} else {
outtype = m2.MAT_TYPE;
}
Mat out = new Mat(m1.rows, m1.cols, outtype);
if (m1.rows != m2.rows || m1.cols != m1.rows) {
return null;
} else {
for (int i = 0; i < m1.rows; i++) {
for (int j = 0; j < m1.cols; j++) {
Object o1 = m1.Get(i, j);
Object o2 = m2.Get(i, j);
float f1 = Float.parseFloat(o1.toString());
float f2 = Float.parseFloat(o2.toString());
float f3 = f1 + f2;
out.Set(i, j, f3);
}
}
}
return out;
}
/**
* 矩阵相加
*
* @param m1 被减数矩阵
* @param m2 减数矩阵
* @return 返回相减矩阵
*/
public static Mat sub(Mat m1, Mat m2) {
int outtype = 1;
if (m1.MAT_TYPE >= m2.MAT_TYPE) {
outtype = m1.MAT_TYPE;
} else {
outtype = m2.MAT_TYPE;
}
Mat out = new Mat(m1.rows, m1.cols, outtype);
if (m1.rows != m2.rows || m1.cols != m1.rows) {
return null;
} else {
for (int i = 0; i < m1.rows; i++) {
for (int j = 0; j < m1.cols; j++) {
Object o1 = m1.Get(i, j);
Object o2 = m2.Get(i, j);
float f1 = Float.parseFloat(o1.toString());
float f2 = Float.parseFloat(o2.toString());
float f3 = f1 - f2;
out.Set(i, j, f3);
}
}
}
return out;
}
/**
* 矩阵相乘
*
* @param m1 矩阵1
* @param m2 矩阵2
* @return 返回相乘矩阵
*/
public static Mat mul(Mat m1, Mat m2) {
//定义输出矩阵的类型，从m1,m2中选出MAT_TYPE较大的类型为输出矩阵的类型
int outtype = 1;
if (m1.MAT_TYPE >= m2.MAT_TYPE) {
outtype = m1.MAT_TYPE;
} else {
outtype = m2.MAT_TYPE;
}
//按照矩阵的乘法，m1.cols=m2.rows成立时才有意义，输出的矩阵的行数等于m1的行数，列数等于m2的列数
Mat out = new Mat(m1.rows, m2.cols, outtype);
if (m1.cols != m2.rows) {
return null;
} else {
//根据判断出的输出矩阵的类型来判断
switch (outtype) {
case MAT_INT:
int value1[] = new int[m1.cols];//m1每一行的数据存储的数组
int value2[] = new int[m2.rows];//m2每一列的数据存储的数组
for (int i = 0; i < m1.rows; i++) {
for (int col = 0; col < m1.cols; col++) {
//得到m1每一行上面的数据存储到数组中
Object o1 = m1.Get(i, col);
value1[col] = Integer.parseInt(o1.toString());
}
for (int j = 0; j < m2.cols; j++) {
for (int row = 0; row < m2.rows; row++) {
//得到m2每一列上的数据存储到数组中
Object o2 = m2.Get(row, j);
value2[row] = Integer.parseInt(o2.toString());
}
//输出矩阵上面将要装入的数据
int value = 0;
//计算输出矩阵上的数据
for (int l = 0; l < value1.length; l++) {
value += value1[l] * value2[l];
}
//设置输出矩阵上的数据
out.Set(i, j, value);
}
}
break;
//同上，只是改了数据的类型
case MAT_FLOAT:
float value11[] = new float[m1.cols];
float value22[] = new float[m2.rows];
for (int i = 0; i < m1.rows; i++) {
for (int col = 0; col < m1.cols; col++) {
Object o1 = m1.Get(i, col);
value11[col] = Float.parseFloat(o1.toString());
}
for (int j = 0; j < m2.cols; j++) {
for (int row = 0; row < m2.rows; row++) {
Object o2 = m2.Get(row, j);
value22[row] = Float.parseFloat(o2.toString());
}
float value = 0;
for (int l = 0; l < value11.length; l++) {
value += value11[l] * value22[l];
}
out.Set(i, j, value);
}
}
break;
case MAT_DOUBLE:
double value111[] = new double[m1.cols];
double value222[] = new double[m2.rows];
for (int i = 0; i < m1.rows; i++) {
for (int col = 0; col < m1.cols; col++) {
Object o1 = m1.Get(i, col);
value111[col] = Double.parseDouble(o1.toString());
}
for (int j = 0; j < m2.cols; j++) {
for (int row = 0; row < m2.rows; row++) {
Object o2 = m2.Get(row, j);
value222[row] = Double.parseDouble(o2.toString());
}
double value = 0;
for (int l = 0; l < value111.length; l++) {
value += value111[l] * value222[l];
}
out.Set(i, j, value);
}
}
break;
default:
break;
}
}
return out;
}
/**
* 矩阵求逆
* 相当如矩阵除法
*
* @param m 输入矩阵
* @return 返回矩阵的逆矩阵
*/
public static Mat inv(Mat m) {
if (m.MAT_TYPE != MAT_INT || m.rows != m.cols) {
return null;
}
int n = m.rows;
int value[][] = new int[n][n];
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
Object o = m.Get(i, j);
value[i][j] = Integer.parseInt(o.toString());
}
}
int result[][] = value;
int resultSum = m.getvalue(value, n);
int temp[][] = new int[n - 1][n - 1];
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
for (int k = 0; k < n - 1; k++) {
for (int g = 0; g < n - 1; g++) {
int flag1 = 0;
int flag2 = 0;
if (k < i) flag1 = 0;
else flag1 = 1;
if (g < j) flag2 = 0;
else flag2 = 1;
temp[k][g] = value[k + flag1][g + flag2];
}
}
int flag3 = -1;
if ((i + j) % 2 == 0) flag3 = 1;
result[j][i] = (int) flag3 * m.getvalue(temp, n - 1) / resultSum;
}
}
Mat out = new Mat(result);
return out;
}从上面我们看到矩阵一些所需要的计算和功能，当然除了矩阵求逆，其他一些功能都相对简单，矩阵求逆笔者也参考了很多前辈的算法，可是很难找到一个快速精准的算法。有关上面的程序，笔者上面有相对详细的注释，这里笔者便不累述了，好了一下分享完成的代码：
package PMat;
import java.util.Vector;
public class Mat {
/**
* Java实现的矩阵类
* author:Pedro
* Date:2017.4.1
*/
public Vector data;
public final static int MAT_INT = 1;
public final static int MAT_FLOAT = 2;
public final static int MAT_DOUBLE = 3;
public int MAT_TYPE = 1;
public int rows;
public int cols;
/**
* @param rows 矩阵的行数，相当于y坐标
* @param cols 矩阵的列数，相当如x坐标
* @param type 矩阵的类型，int,float,double三种
*/
public Mat(int rows, int cols, int type) {
this.rows = rows;
this.cols = cols;
switch (type) {
case MAT_INT:
int zerosi = 0;
data = new Vector<Vector>(rows);
for (int i = 0; i < rows; i++) {
Vector v = new Vector<Integer>(cols);
for (int j = 0; j < cols; j++) {
v.add(j, zerosi);
}
data.add(i, v);
}
break;
case MAT_FLOAT:
float zerosf = 0;
this.MAT_TYPE = 2;
data = new Vector<Vector>(rows);
for (int i = 0; i < rows; i++) {
Vector v = new Vector<Float>(cols);
for (int j = 0; j < cols; j++) {
v.add(j, zerosf);
}
data.add(i, v);
}
break;
case MAT_DOUBLE:
this.MAT_TYPE = 3;
float zerosd = 0;
data = new Vector<Vector>(rows);
for (int i = 0; i < rows; i++) {
Vector v = new Vector<Double>(cols);
for (int j = 0; j < cols; j++) {
v.add(j, zerosd);
}
data.add(i, v);
}
break;
default:
break;
}
}
public Mat(int rows, int cols) {
this.rows = rows;
this.cols = cols;
int zeros = 0;
data = new Vector<Vector>(rows);
for (int i = 0; i < rows; i++) {
Vector v = new Vector<Integer>(cols);
for (int j = 0; j < cols; j++) {
v.add(j, zeros);
}
data.add(i, v);
}
}
public Mat() {
this(5, 5);
}
/**
* @param num 以数组的方式来构造矩阵
*/
public Mat(int num[][]) {
this.rows = num.length;
this.cols = num[0].length;
this.MAT_TYPE = MAT_INT;
data = new Vector<Vector>(rows);
for (int i = 0; i < rows; i++) {
Vector v = new Vector<Integer>(cols);
for (int j = 0; j < cols; j++) {
v.add(j, num[i][j]);
}
data.add(i, v);
}
}
public Mat(float num[][]) {
this.rows = num.length;
this.cols = num[0].length;
this.MAT_TYPE = MAT_FLOAT;
data = new Vector<Vector>(rows);
for (int i = 0; i < rows; i++) {
Vector v = new Vector<Float>(cols);
for (int j = 0; j < cols; j++) {
v.add(j, num[i][j]);
}
data.add(i, v);
}
}
public Mat(double num[][]) {
this.rows = num.length;
this.cols = num[0].length;
this.MAT_TYPE = MAT_DOUBLE;
data = new Vector<Vector>(rows);
for (int i = 0; i < rows; i++) {
Vector v = new Vector<Double>(cols);
for (int j = 0; j < cols; j++) {
v.add(j, num[i][j]);
}
data.add(i, v);
}
}
/**
* 输出矩阵中的内容
*/
public void print() {
System.out.println("[");
for (int i = 0; i < rows; i++) {
Vector v = (Vector) data.get(i);
for (int j = 0; j < cols; j++) {
System.out.print(v.get(j) + ",");
}
System.out.println();
}
System.out.println("]");
}
/**
* 将矩阵中的元素全部置0
*/
public void zeros() {
if (MAT_TYPE == MAT_INT) {
int zerosi = 0;
for (int i = 0; i < rows; i++) {
Vector v = (Vector) data.get(i);
for (int j = 0; j < cols; j++) {
v.set(j, zerosi);
}
data.set(i, v);
}
} else if (MAT_TYPE == MAT_FLOAT) {
float zerosf = 0;
for (int i = 0; i < rows; i++) {
Vector v = (Vector) data.get(i);
for (int j = 0; j < cols; j++) {
v.set(j, zerosf);
}
data.set(i, v);
}
} else {
for (int i = 0; i < rows; i++) {
double zerosd = 0;
Vector v = (Vector) data.get(i);
for (int j = 0; j < cols; j++) {
v.set(j, zerosd);
}
data.set(i, v);
}
}
}
/**
* 将矩阵中的元素全部置1
*/
public void ones() {
if (MAT_TYPE == MAT_INT) {
int onesi = 1;
for (int x = 0; x < rows; x++) {
Vector v = (Vector) data.get(x);
for (int y = 0; y < cols; y++) {
v.set(y, onesi);
}
data.set(x, v);
}
} else if (MAT_TYPE == MAT_FLOAT) {
float onesf = 1;
for (int i = 0; i < rows; i++) {
Vector v = (Vector) data.get(i);
for (int j = 0; j < cols; j++) {
v.set(j, onesf);
}
data.set(i, v);
}
} else {
for (int i = 0; i < rows; i++) {
double onesd = 1;
Vector v = (Vector) data.get(i);
for (int j = 0; j < cols; j++) {
v.set(j, onesd);
}
data.set(i, v);
}
}
}
/**
* 矩阵转置
*/
public void T() {
if (MAT_TYPE == MAT_INT) {
Vector t = new Vector<Vector>(cols);
for (int i = 0; i < cols; i++) {
Vector v = new Vector<Integer>(rows);
for (int j = 0; j < rows; j++) {
Vector oldc = (Vector) data.get(j);
v.add(j, oldc.get(i));
}
t.add(i, v);
}
data = t;
int tmp = this.rows;
this.rows = this.cols;
this.cols = tmp;
} else if (MAT_TYPE == MAT_FLOAT) {
Vector t = new Vector<Vector>(cols);
for (int i = 0; i < cols; i++) {
Vector v = new Vector<Float>(rows);
for (int j = 0; j < rows; j++) {
Vector oldc = (Vector) data.get(j);
v.add(j, oldc.get(i));
}
t.add(i, v);
}
data = t;
int tmp = this.rows;
this.rows = this.cols;
this.cols = tmp;
} else {
Vector t = new Vector<Vector>(cols);
for (int i = 0; i < cols; i++) {
Vector v = new Vector<Double>(rows);
for (int j = 0; j < rows; j++) {
Vector oldc = (Vector) data.get(j);
v.add(j, oldc.get(i));
}
t.add(i, v);
}
data = t;
int tmp = this.rows;
this.rows = this.cols;
this.cols = tmp;
}
}
/**
* 设置矩阵中某个坐标的元素内容
*
* @param rowindex y坐标
* @param colindex x坐标
* @param num 要输入的内容
*/
public void Set(int rowindex, int colindex, Object num) {
Vector oldc = (Vector) data.get(rowindex);
if (MAT_TYPE == MAT_INT) {
int score = Integer.parseInt(num.toString());
oldc.set(colindex, score);
} else if (MAT_TYPE == MAT_FLOAT) {
float score = Float.parseFloat(num.toString());
oldc.set(colindex, score);
} else {
double score = Double.parseDouble(num.toString());
oldc.set(colindex, score);
}
}
/**
* 得到矩阵中某个坐标元素的内容
*
* @param rowindex y坐标
* @param colindex x坐标
* @return 返回一个object类型
*/
public Object Get(int rowindex, int colindex) {
Vector oldc = (Vector) data.get(rowindex);
return oldc.get(colindex);
}
/**
* 矩阵行列式求值
*
* @param num 矩阵的数据，以数组输入
* @param n 矩阵的行列数
* @return 返回行列式的值
*/
public int getvalue(int num[][], int n) {
int value = 0;
if (n == 1) return num[0][0];
int temp[][] = new int[n - 1][n - 1];
for (int i = 0; i < n; i++) {
for (int j = 0; j < n - 1; j++) {
for (int k = 0; k < n - 1; k++) {
int flag;
if (j < i) flag = 0;
else flag = 1;
temp[j][k] = num[j + flag][k + 1];
}
}
int flag2 = -1;
if (i % 2 == 0) flag2 = 1;
value += flag2 * num[i][0] * getvalue(temp, n - 1);
}
return value;
}
/**
* 矩阵行列式求值
*
* @return
*/
public int dot() {
if (MAT_TYPE != MAT_INT || rows != cols) {
return -1;
}
int value[][] = new int[rows][cols];
for (int i = 0; i < rows; i++) {
for (int j = 0; j < cols; j++) {
Object o = Get(i, j);
value[i][j] = Integer.parseInt(o.toString());
}
}
int fianl = getvalue(value, rows);
return fianl;
}
/**
* 矩阵相加
*
* @param m1 矩阵1
* @param m2 矩阵2
* @return 返回相加的矩阵
*/
public static Mat add(Mat m1, Mat m2) {
int outtype = 1;
if (m1.MAT_TYPE >= m2.MAT_TYPE) {
outtype = m1.MAT_TYPE;
} else {
outtype = m2.MAT_TYPE;
}
Mat out = new Mat(m1.rows, m1.cols, outtype);
if (m1.rows != m2.rows || m1.cols != m1.rows) {
return null;
} else {
for (int i = 0; i < m1.rows; i++) {
for (int j = 0; j < m1.cols; j++) {
Object o1 = m1.Get(i, j);
Object o2 = m2.Get(i, j);
float f1 = Float.parseFloat(o1.toString());
float f2 = Float.parseFloat(o2.toString());
float f3 = f1 + f2;
out.Set(i, j, f3);
}
}
}
return out;
}
/**
* 矩阵相加
*
* @param m1 被减数矩阵
* @param m2 减数矩阵
* @return 返回相减矩阵
*/
public static Mat sub(Mat m1, Mat m2) {
int outtype = 1;
if (m1.MAT_TYPE >= m2.MAT_TYPE) {
outtype = m1.MAT_TYPE;
} else {
outtype = m2.MAT_TYPE;
}
Mat out = new Mat(m1.rows, m1.cols, outtype);
if (m1.rows != m2.rows || m1.cols != m1.rows) {
return null;
} else {
for (int i = 0; i < m1.rows; i++) {
for (int j = 0; j < m1.cols; j++) {
Object o1 = m1.Get(i, j);
Object o2 = m2.Get(i, j);
float f1 = Float.parseFloat(o1.toString());
float f2 = Float.parseFloat(o2.toString());
float f3 = f1 - f2;
out.Set(i, j, f3);
}
}
}
return out;
}
/**
* 矩阵相乘
*
* @param m1 矩阵1
* @param m2 矩阵2
* @return 返回相乘矩阵
*/
public static Mat mul(Mat m1, Mat m2) {
//定义输出矩阵的类型，从m1,m2中选出MAT_TYPE较大的类型为输出矩阵的类型
int outtype = 1;
if (m1.MAT_TYPE >= m2.MAT_TYPE) {
outtype = m1.MAT_TYPE;
} else {
outtype = m2.MAT_TYPE;
}
//按照矩阵的乘法，m1.cols=m2.rows成立时才有意义，输出的矩阵的行数等于m1的行数，列数等于m2的列数
Mat out = new Mat(m1.rows, m2.cols, outtype);
if (m1.cols != m2.rows) {
return null;
} else {
//根据判断出的输出矩阵的类型来判断
switch (outtype) {
case MAT_INT:
int value1[] = new int[m1.cols];//m1每一行的数据存储的数组
int value2[] = new int[m2.rows];//m2每一列的数据存储的数组
for (int i = 0; i < m1.rows; i++) {
for (int col = 0; col < m1.cols; col++) {
//得到m1每一行上面的数据存储到数组中
Object o1 = m1.Get(i, col);
value1[col] = Integer.parseInt(o1.toString());
}
for (int j = 0; j < m2.cols; j++) {
for (int row = 0; row < m2.rows; row++) {
//得到m2每一列上的数据存储到数组中
Object o2 = m2.Get(row, j);
value2[row] = Integer.parseInt(o2.toString());
}
//输出矩阵上面将要装入的数据
int value = 0;
//计算输出矩阵上的数据
for (int l = 0; l < value1.length; l++) {
value += value1[l] * value2[l];
}
//设置输出矩阵上的数据
out.Set(i, j, value);
}
}
break;
//同上，只是改了数据的类型
case MAT_FLOAT:
float value11[] = new float[m1.cols];
float value22[] = new float[m2.rows];
for (int i = 0; i < m1.rows; i++) {
for (int col = 0; col < m1.cols; col++) {
Object o1 = m1.Get(i, col);
value11[col] = Float.parseFloat(o1.toString());
}
for (int j = 0; j < m2.cols; j++) {
for (int row = 0; row < m2.rows; row++) {
Object o2 = m2.Get(row, j);
value22[row] = Float.parseFloat(o2.toString());
}
float value = 0;
for (int l = 0; l < value11.length; l++) {
value += value11[l] * value22[l];
}
out.Set(i, j, value);
}
}
break;
case MAT_DOUBLE:
double value111[] = new double[m1.cols];
double value222[] = new double[m2.rows];
for (int i = 0; i < m1.rows; i++) {
for (int col = 0; col < m1.cols; col++) {
Object o1 = m1.Get(i, col);
value111[col] = Double.parseDouble(o1.toString());
}
for (int j = 0; j < m2.cols; j++) {
for (int row = 0; row < m2.rows; row++) {
Object o2 = m2.Get(row, j);
value222[row] = Double.parseDouble(o2.toString());
}
double value = 0;
for (int l = 0; l < value111.length; l++) {
value += value111[l] * value222[l];
}
out.Set(i, j, value);
}
}
break;
default:
break;
}
}
return out;
}
/**
* 矩阵求逆
* 相当如矩阵除法
*
* @param m 输入矩阵
* @return 返回矩阵的逆矩阵
*/
public static Mat inv(Mat m) {
if (m.MAT_TYPE != MAT_INT || m.rows != m.cols) {
return null;
}
int n = m.rows;
int value[][] = new int[n][n];
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
Object o = m.Get(i, j);
value[i][j] = Integer.parseInt(o.toString());
}
}
int result[][] = value;
int resultSum = m.getvalue(value, n);
int temp[][] = new int[n - 1][n - 1];
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
for (int k = 0; k < n - 1; k++) {
for (int g = 0; g < n - 1; g++) {
int flag1 = 0;
int flag2 = 0;
if (k < i) flag1 = 0;
else flag1 = 1;
if (g < j) flag2 = 0;
else flag2 = 1;
temp[k][g] = value[k + flag1][g + flag2];
}
}
int flag3 = -1;
if ((i + j) % 2 == 0) flag3 = 1;
result[j][i] = (int) flag3 * m.getvalue(temp, n - 1) / resultSum;
}
}
Mat out = new Mat(result);
return out;
}
}
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