diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..fd20fdd
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+
+*.pyc
diff --git a/codes.Java/Fraction.java b/codes.Java/Fraction.java
new file mode 100644
index 0000000..f30c6e0
--- /dev/null
+++ b/codes.Java/Fraction.java
@@ -0,0 +1,167 @@
+package com.utils.wycode;
+
+public class Fraction {
+private Integer numerator; // 分子;
+private Integer denominator; // 分母
+
+/**
+* 构造器
+*/
+public Fraction() {
+}
+
+public Fraction(Integer numerator, Integer denominator) {
+this.numerator = numerator;
+this.denominator = denominator;
+}
+
+public Integer getDenominator() {
+return denominator;
+}
+
+public void setDenominator(Integer denominator) {
+this.denominator = denominator;
+}
+
+public Integer getNumerator() {
+return numerator;
+}
+
+public void setNumerator(Integer numerator) {
+this.numerator = numerator;
+}
+
+/**
+* 求最大公约数
+* 
+* @return
+*/
+private int getGCD(int a, int b) {
+int max = Math.max(a, b);
+int min = Math.min(a, b);
+int mod = max % min;
+if (mod == 0) {
+return min;
+} else {
+return this.getGCD(mod, min);
+}
+}
+
+/**
+* 简化和约分
+* 
+* @return
+*/
+public Fraction simplify() {
+// 格式化
+if (this.numerator == 0) {
+this.denominator = null;
+return this;
+} else if (this.denominator * this.numerator > 0
+&& this.denominator < 0) {
+this.denominator = Math.abs(this.denominator);
+this.numerator = Math.abs(this.numerator);
+return this;
+} else if (this.denominator < 0) {
+this.denominator = Math.abs(this.denominator);
+this.numerator = -this.numerator;
+return this;
+}
+// 约分
+int gcd = this.getGCD(Math.abs(denominator), Math.abs(numerator));
+if (gcd == 1) {
+return this;
+} else {
+this.denominator = this.denominator / gcd;
+this.numerator = this.numerator / gcd;
+return this;
+}
+}
+
+/**
+* 加法
+* 
+* @param fraction
+* @return
+*/
+public Fraction add(Fraction fraction) {
+Integer resultDenominator = Math.abs(this.denominator)
+* Math.abs(fraction.getDenominator());
+Integer resultNumerator = this.numerator * fraction.getDenominator()
++ this.denominator * fraction.getNumerator();
+Fraction result = new Fraction(resultNumerator, resultDenominator);
+return result.simplify();
+}
+
+/**
+* 减法
+* 
+* @param fraction
+* @return
+*/
+public Fraction minus(Fraction fraction) {
+Integer resultDenominator = Math.abs(this.denominator)
+* Math.abs(fraction.getDenominator());
+Integer resultNumerator = this.numerator * fraction.getDenominator()
+- this.denominator * fraction.getNumerator();
+Fraction result = new Fraction(resultNumerator, resultDenominator);
+return result.simplify();
+}
+
+/**
+* 乘法
+* 
+* @param fraction
+* @return
+*/
+public Fraction multiply(Fraction fraction) {
+Fraction result = null;
+if (this.numerator == 0 || fraction.numerator == 0) {
+result = new Fraction(0, null);
+}
+Integer resultDenominator = this.denominator
+* fraction.getDenominator();
+Integer resultNumerator = this.numerator * fraction.getNumerator();
+result = new Fraction(resultNumerator, resultDenominator);
+return result.simplify();
+}
+
+/**
+*除法
+* 
+* @param fraction
+* @return
+*/
+public Fraction divide(Fraction fraction) {
+Fraction result = null;
+if (this.numerator == 0) {
+result = new Fraction(0, null);
+}
+Integer resultDenominator = this.denominator * fraction.getNumerator();
+Integer resultNumerator = this.numerator * fraction.getDenominator();
+result = new Fraction(resultNumerator, resultDenominator);
+return result.simplify();
+}
+
+@Override
+public String toString() {
+return this.numerator + "/" + this.denominator;
+}
+
+/**
+* 测试
+* 
+* @param args
+*/
+public static void main(String[] args) {
+Fraction f1 = new Fraction(1, 2);
+Fraction f2 = new Fraction(2, 4);
+System.out.println(f1);
+System.out.println(f2);
+System.out.println(f2.simplify());
+System.out.println(f1.add(f2));
+System.out.println(f1.minus(f2));
+System.out.println(f1.multiply(f2));
+System.out.println(f1.divide(f2));
+}
+} 
diff --git a/codes.Java/Jama-1.0.2.jar b/codes.Java/Jama-1.0.2.jar
new file mode 100644
index 0000000..824d133
Binary files /dev/null and b/codes.Java/Jama-1.0.2.jar differ
diff --git a/codes.Java/Matrix.java b/codes.Java/Matrix.java
new file mode 100644
index 0000000..b6154ea
--- /dev/null
+++ b/codes.Java/Matrix.java
@@ -0,0 +1,150 @@
+package com.utils.wycode;
+
+public class Matrix {
+	private String[][] m;
+	private int row;
+	private int column;
+	
+	public Matrix(String[][] m) {
+		  this.m=m;
+		  this.row=m.length;
+		  this.column=m[0].length;
+	}
+	
+	public static Matrix mulMatrix(Matrix a,Matrix b) {
+		int myrow=a.getRow();
+		int mycolumn=b.getColumn();
+		String[][] result=new String[myrow][mycolumn];
+		String atemp="";
+		String btemp="";
+		for(int i=0;i<myrow;i++)
+			for(int j=0;j<mycolumn;j++) {
+				result[i][j]="";
+			}
+		String[][] a1=a.getM();
+		String[][] b1=b.getM();
+		//***************************************************************************
+        for(int i=0;i<myrow;i++) {
+        	   for(int j=0;j<mycolumn;j++) {
+        		   for(int k=0;k<myrow;k++) {
+        			   if(a1[i][k].equals("0") || b1[k][j].equals("0")) {
+        				   result[i][j]+="";
+        			   }else if(a1[i][k].equals("1")) {
+        				   if(b1[k][j].contains("-")) {
+        					   result[i][j]+=b1[k][j]; 
+        				   }else {
+        					   result[i][j]+="+"+b1[k][j];
+        				   }
+        				   
+        			   }else if(b1[k][j].equals("1")) {
+        				   if(a1[i][k].contains("-")) {
+        					   result[i][j]+=a1[i][k];
+        				   }else {
+        					   result[i][j]+="+"+a1[i][k];	   
+        				   }
+        				
+        			   }else if(b1[k][j].equals("-1")) {
+        				   if(a1[i][k].contains("-")) {
+        					   atemp=a1[i][k].substring(1,a1[i][k].length());
+        					   result[i][j]+="+"+atemp;
+        				   }else {
+        					   result[i][j]+="-"+a1[i][k];	   
+        				   }
+        				
+        			   }else if(a1[i][k].equals("-1")) {
+        				   if(b1[k][j].contains("-")) {
+        					   btemp=b1[k][j].substring(1,b1[k][j].length());
+        					   result[i][j]+="+"+btemp; 
+        				   }else {
+        					   result[i][j]+="-"+b1[k][j];
+        				   }
+        				   
+        			   }else {
+        				   if(b1[k][j].contains("-")) {
+        					  if(a1[i][k].contains("-")) {
+        						  atemp=a1[i][k].substring(1,a1[i][k].length());
+        						  btemp=b1[k][j].substring(1,b1[k][j].length());
+        						  result[i][j]+=atemp+"*"+btemp;
+        					  }else {
+        						  btemp=b1[k][j].substring(1,b1[k][j].length());
+        						  result[i][j]+="-"+a1[i][k]+"*"+btemp;
+        					 }
+        					   
+        				   }else {
+        					   if(a1[i][k].contains("-")) {
+         						  atemp=a1[i][k].substring(1,a1[i][k].length());
+         						 
+         						  result[i][j]+="-"+atemp+"*"+b1[k][j];
+         					  }else {
+         						
+         						  result[i][j]+="+"+a1[i][k]+"*"+b1[k][j];
+         					 }
+        				   }
+        			   }
+        				   
+        			 
+        		   }
+        		   
+        	   }
+        }
+        
+        
+        //***************************************************************************
+        return new Matrix(result);
+	}
+	
+	@Override
+	public String toString() {
+		String temp="";
+		String[][] array=this.getM();
+	    for (int i=0;i<row;i++) {
+	    	for(int j=0;j<column;j++) {
+	    		temp+=array[i][j]+"\t";
+	    	}
+	    	temp+="\n";
+	    }
+	    return temp;
+		
+	}
+     public String[][] getM() {
+		return m;
+	}
+
+	public void setM(String[][] m) {
+		this.m = m;
+	}
+
+	public int getRow() {
+		return row;
+	}
+
+	public void setRow(int row) {
+		this.row = row;
+	}
+
+	public int getColumn() {
+		return column;
+	}
+
+	public void setColumn(int column) {
+		this.column = column;
+	}
+
+	public static void main(String[] args) {
+		String[][] R=new String[3][3];
+		String[][] b=new String[3][3];
+		
+		R[0][0]="cos(t)";
+		R[0][1]="sin(t)";
+		R[0][2]="0";
+		R[1][0]="-sin(t)";
+		R[1][1]="cos(t)";
+		R[1][2]="0";
+		R[2][0]="0";
+		R[2][1]="0";
+		R[2][2]="-1";
+		Matrix a=new Matrix(R);
+		
+		System.out.print(a);
+	}
+}
diff --git a/codes.Java/p1.java b/codes.Java/p1.java
new file mode 100644
index 0000000..d69a9b5
--- /dev/null
+++ b/codes.Java/p1.java
@@ -0,0 +1,17 @@
+package com.mat2java.wycode;
+public class p1 {
+    public static void main(String[] args) {
+    	int n=10;
+		double[] p=new double[n];
+		
+		for(int i=0;i<n;i++) {
+			p[i]=0.1;
+			
+		}
+		
+		
+		for(double a:p) {
+			System.out.println(a);
+		}
+	}
+}
diff --git a/codes.Java/p10.java b/codes.Java/p10.java
new file mode 100644
index 0000000..5d36b3f
--- /dev/null
+++ b/codes.Java/p10.java
@@ -0,0 +1,53 @@
+package com.mat2java.wycode;
+
+import Jama.Matrix;
+
+public class p10 {
+    public static void main(String[] args) {
+		String[][] world = {{"red","green","green","red","red"},
+				            {"red","red","green","red","red"},
+				            {"red","red","green","green","red"},
+				            {"red","red","red","red","red"}};
+		
+		int nRow = world.length;
+		int nCol = world[0].length;
+		
+		double pStart = 0.7;
+		double[][] p = new double[nRow][nCol];
+		for(int i = 0; i < nRow; i++) {
+			for(int j = 0; j < nCol; j++) {
+				p[i][j] = (1 - pStart) / (nRow * nCol - 1);
+			}
+		}
+		p[2][1] = pStart;
+		
+		int[] stop = {0, 0};
+		int[] right = {0, 1};
+		int[] left = {0, -1};
+		int[] down = {1, 0};
+		int[] up = {-1, 0};
+		
+		double pMoveCorrect = 0.8;
+		double[][] q = move1(p, right, pMoveCorrect);
+		for(int i = 0; i < q.length; i++) {
+			for(int j = 0; j < q[0].length; j++) {
+				System.out.printf("%1.4f%s", p[i][j], " " );
+			}
+			System.out.println();
+		}
+	}
+    
+    public static double[][] move1(double[][] p, int[] u, double pMoveCorrect){
+    	int nRow = p.length;
+    	int nCol = p[0].length;
+    	
+    	double[][] q = new double[nRow][nCol];
+    	
+    	for(int i = 0; i < nRow; i++) {
+    		for(int j = 0; j < nCol; j++ ) {
+    			q[i][j] = pMoveCorrect * p[(i - 1 - u[0]) % nRow + 1][(j - 1 - u[1]) / nCol + 1] + (1 - pMoveCorrect) * p[i][j];
+    		}
+    	}
+    	return q;
+    }
+}
diff --git a/codes.Java/p2.java b/codes.Java/p2.java
new file mode 100644
index 0000000..d72d416
--- /dev/null
+++ b/codes.Java/p2.java
@@ -0,0 +1,42 @@
+package com.mat2java.wycode;
+
+import java.util.List;
+import java.util.ArrayList;
+
+import com.utils.wycode.*;
+
+public class p2 {
+	
+   public static List<Fraction> move(List<Fraction> p,double u){
+	   int n=p.size();
+	   List<Fraction> q=new ArrayList<>();
+	   for(int i=0;i<n;i++) {
+		   if(0==i){
+		   q.add(p.get(n-1));
+		   }else {
+			   q.add(p.get(i-1));
+		   }
+		   
+	   }
+	   return q;
+   }
+   public static void main(String[] args) {
+	   List<Fraction> p= new ArrayList<>();
+	   p.add(new Fraction(1,9));
+	   p.add(new Fraction(1,3));
+	   p.add(new Fraction(1,3));
+	   p.add(new Fraction(1,9));
+	   p.add(new Fraction(1,9));
+	   
+	   
+	   List<Fraction> q=move(p, 1);
+	   for(Fraction a:p) {
+		   System.out.print(a+" ");
+	   }
+       System.out.println();
+	   for(Fraction a:q) {
+		   System.out.print(a+" ");
+	   }
+	 
+    }
+}
diff --git a/codes.Java/p3.java b/codes.Java/p3.java
new file mode 100644
index 0000000..7d9c5ad
--- /dev/null
+++ b/codes.Java/p3.java
@@ -0,0 +1,41 @@
+package com.mat2java.wycode;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class p3 {
+  public static Double compMean(List<Double> x) {
+	  Double s=new Double(0);
+	  for(Double t:x) {
+		  s=Double.sum(s, t);
+	  }
+	  return s/x.size();
+  }
+  
+  public static Double compVariance(List< Double> x) {
+	  Double mu=compMean(x);
+	  List<Double> x2=new ArrayList<>();
+	  //Double[] x2=new Double[x.size()];
+	  
+	  for(int i=0;i<x.size();i++) {
+		  x2.add((x.get(i)-mu)*(x.get(i)-mu));
+	  }
+	  
+	  return compMean(x2);
+  }
+  
+  public static void main(String[] args) {
+	  List<Double> x=new ArrayList<>();
+	  
+	  x.add(new Double(7));
+	  x.add(new Double(38));
+	  x.add(new Double(4));
+	  x.add(new Double(23));
+	  x.add(new Double(18));
+
+	  System.out.printf("The Expectation / Mean: \t %.1f \n",compMean(x));
+	  System.out.printf("The Variance is:\t\t %.1f \n",compVariance(x));
+	  System.out.printf("The Standard Deviation is:\t %.1f \n",Math.sqrt(compVariance(x)));
+	  
+  }
+}
diff --git a/codes.Java/p4.java b/codes.Java/p4.java
new file mode 100644
index 0000000..a107b93
--- /dev/null
+++ b/codes.Java/p4.java
@@ -0,0 +1,43 @@
+package com.mat2java.wycode;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class p4 {
+	 public static Double compMean(List<Double> x) {
+		  Double s=new Double(0);
+		  for(Double t:x) {
+			  s=Double.sum(s, t);
+		  }
+		  return s/x.size();
+	  }
+	  
+
+	  
+	  public static void main(String[] args) {
+	    double a=2;
+	    double b=4;
+	    
+		  List<Double> x=new ArrayList<>();
+		  
+		  x.add(new Double(7));
+		  x.add(new Double(38));
+		  x.add(new Double(4));
+		  x.add(new Double(23));
+		  x.add(new Double(18));
+		  
+		  List<Double> y=new ArrayList<>();
+		  for(int i=0;i<x.size();i++) {
+		     y.add(x.get(i)*a+b);	  
+		  }
+		  
+		  Double xmu=compMean(x);
+		  Double ymu=compMean(y);
+		  
+		  
+		  System.out.printf("a * Xmu + b \t= %.2f \n",a*xmu+b);
+		  System.out.printf("Ymu \t\t= %.2f \n",ymu);
+		  
+		 
+	  }
+}
diff --git a/codes.Java/p5.java b/codes.Java/p5.java
new file mode 100644
index 0000000..3160d2c
--- /dev/null
+++ b/codes.Java/p5.java
@@ -0,0 +1,50 @@
+package com.mat2java.wycode;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class p5 {
+	  public static Double compMean(List<Double> x) {
+		  Double s=new Double(0);
+		  for(Double t:x) {
+			  s=Double.sum(s, t);
+		  }
+		  return s/x.size();
+	  }
+	  
+	  public static Double compVariance(List< Double> x) {
+		  Double mu=compMean(x);
+		  List<Double> x2=new ArrayList<>();
+		  //Double[] x2=new Double[x.size()];
+		  
+		  for(int i=0;i<x.size();i++) {
+			  x2.add((x.get(i)-mu)*(x.get(i)-mu));
+		  }
+		  
+		  return compMean(x2);
+	  }
+	  
+	  public static void main(String[] args) {
+		  List<Double> x=new ArrayList<>();
+		  
+		  x.add(new Double(7));
+		  x.add(new Double(38));
+		  x.add(new Double(4));
+		  x.add(new Double(23));
+		  x.add(new Double(18));
+ 
+		  List<Double> x2=new ArrayList<>();
+	
+		  for(int i=0;i<x.size();i++) {
+		     x2.add(x.get(i)*x.get(i));	  
+		  }
+		  
+		  Double x2mu=compMean(x2);
+		  Double xmu=compMean(x);
+		  Double xvar=compVariance(x);
+		  
+		  System.out.printf("The Variance of X \t= %.2f \n",xvar);
+		  System.out.printf("E[X^2]-E[X]^2 \t\t= %.2f \n", x2mu - xmu*xmu);
+		  
+	  }
+}
diff --git a/codes.Java/p6.java b/codes.Java/p6.java
new file mode 100644
index 0000000..d785331
--- /dev/null
+++ b/codes.Java/p6.java
@@ -0,0 +1,57 @@
+package com.mat2java.wycode;
+
+import com.utils.wycode.Matrix;
+
+public class p6 {
+    public static void main(String[] args) {
+    	String[][] a=new String[3][3];
+		String[][] b=new String[3][1];
+		String[][] c=new String[3][1];
+		String[][] d=new String[3][3];
+		
+		a[0][0]="cos(t)";
+		a[0][1]="sin(t)";
+		a[0][2]="0";
+		a[1][0]="-sin(t)";
+		a[1][1]="cos(t)";
+		a[1][2]="0";
+		a[2][0]="0";
+		a[2][1]="0";
+		a[2][2]="1";
+		Matrix R=new Matrix(a);
+		
+		
+		d[0][0]="-cos(t)";
+		d[0][1]="-sin(t)";
+		d[0][2]="0";
+		d[1][0]="sin(t)";
+		d[1][1]="-cos(t)";
+		d[1][2]="0";
+		d[2][0]="0";
+		d[2][1]="0";
+		d[2][2]="-1";
+		Matrix invR=new Matrix(d);
+		
+		b[0][0]="x";
+		b[1][0]="y";
+		b[2][0]="t";
+		Matrix X=new Matrix(b);
+		
+		c[0][0]="-x";
+		c[1][0]="-y";
+		c[2][0]="-t";
+		Matrix negX=new Matrix(c);
+		
+		Matrix r1=Matrix.mulMatrix(R, negX);
+		
+		Matrix r2=Matrix.mulMatrix(invR, X);
+		
+		System.out.println("R*(-X) is:");
+		System.out.println(r1);
+	
+		System.out.println("*****************");
+		System.out.println("inv(R)*X is:");
+		System.out.println(r1);
+		
+	}
+}
diff --git a/codes.Java/p7.java b/codes.Java/p7.java
new file mode 100644
index 0000000..bb48f0a
--- /dev/null
+++ b/codes.Java/p7.java
@@ -0,0 +1,35 @@
+package com.mat2java.wycode;
+
+public class p7 {
+    public static void main(String[] args) {
+		String[] world =  {"green" , "red" , "red", "green", "green"};
+		double[] p = {0.2 ,0.2 ,0.2, 0.2 ,0.2};
+		String z = "red";
+		double pHit = 0.6;
+		double pMiss = 0.2;
+		
+		double[] q = sense(p, z, world, pHit, pMiss);
+    	
+		for(int i = 0;i < q.length; i++) {
+    		System.out.print(q[i] + " ");
+    	}
+		
+		
+	}
+    
+    public static double[] sense(double[] p, String z, String[] world, double pHit, double pMiss){
+    	double[] q = new double[p.length];
+    	double sum = 0;
+    	for(int i = 0;i < q.length; i++) {
+    		int hit = z.equals(world[i]) ? 1 : 0;
+    		q[i] = p[i] * (hit * pHit + (1 - hit) * pMiss);
+    		sum += q[i];
+    	}
+    	
+    	for(int i = 0;i < q.length; i++) {
+    		q[i] = q[i] / sum;
+    	}
+    	
+    	return q;
+    }
+}
\ No newline at end of file
diff --git a/codes.Java/p8.java b/codes.Java/p8.java
new file mode 100644
index 0000000..3ebe7af
--- /dev/null
+++ b/codes.Java/p8.java
@@ -0,0 +1,33 @@
+package com.mat2java.wycode;
+
+public class p8 {
+    public static void main(String[] args) {
+		double pCan = 0.001;
+		double pNon = 0.999;
+		
+		String z = "positive";
+		
+		double pPosCan = 0.8;
+		double pPosNon = 0.1;
+		
+		double[] p = new double[2];
+		
+		if(z.equals("positive")) {
+			p[0] = pPosCan * pCan;
+			p[1] = pPosNon * pNon;
+		}
+		else {
+			p[0] = (1 - pPosCan) * pCan; 
+			p[1] = (1 - pPosNon) * pNon;
+		}
+		
+		double sum = p[0] + p[1];
+		for(int i = 0; i < p.length; i++) {
+			p[i] = p[i] / sum;
+		}
+		System.out.printf("The probability of having cancer given the %s test:\n", z);
+		System.out.println(p[0]);
+		System.out.printf("The probability of cancer free given the %s test:\n", z);		
+		System.out.println(p[1]);
+	}
+}
diff --git a/codes.Java/p9.java b/codes.Java/p9.java
new file mode 100644
index 0000000..9b4d42a
--- /dev/null
+++ b/codes.Java/p9.java
@@ -0,0 +1,27 @@
+package com.mat2java.wycode;
+
+import Jama.Matrix;
+
+public class p9 {
+    public static void main(String[] args) {
+		double a = 1, b = 2, c = 3, d = 4, e = 5, f = 6, g = 7;
+		
+		
+		double[][] mu1 = {{a},{b}};
+		Matrix mu = new Matrix(mu1);
+
+        double[][] invSigma1 = {{c,d},{d,e}};
+		Matrix invSigma = new Matrix(invSigma1);
+
+		
+		double[][] x1 = {{f},{g}};
+
+		Matrix x = new Matrix(x1);
+
+
+		mu.transpose().times(invSigma).times(x).print(3, 2);
+		x.transpose().times(invSigma).times(mu).print(3, 2);;
+		
+
+	}
+}