When we graduated that does not mean we should stop learning, this is what at least I believe. These days after graduation I worked on some projects, below is one of them:

This was a program I created after university to keep my skills, up-to-date.
As I am a passionate Mathematical, I created a program which allowed me to find out “determinant” of the 3x3 matrix coefficients and also find whether the matrix has any solution. In other word, I found out whether this matrix has any dependent or independent row. I used many Array, ArrayList, double and other primitive types to accomplish this program.

You can download the code here. Below is small part of code.

```import java.io.IOException;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Scanner;

/**
*
* @author Mehdi Dana
* @date 25/07/2012
*
*/

public class MathDana {
/**
* @param args
* @throws IOException
*/

// round a double value
public static double roundTwoDecimals(double d) {
DecimalFormat twoDForm = new DecimalFormat("#.##");
return Double.valueOf(twoDForm.format(d));
}
// compare two arraylist, whether they are the same or not
public static boolean compareArrayList(ArrayList< Double> arr1, ArrayList< Double> arr2){
boolean ans = true;
for(int i=0; i < arr1.size(); i++){
double tem1 = roundTwoDecimals( arr1.get(i));
double tem2 = roundTwoDecimals( arr2.get(i));
if(tem1 != tem2){
ans = false;
//System.out.println(temp);
}
}
return ans;
}

// many methods here

// main method
public static void main(String[] args) throws IOException {
try {
// a lot code here
}catch(Exception e){
// e.printStackTrace(); // to track error if there is
}
}

}

```