public static double[] LineEquation (int x1, int y1, int x2, int y2)
   {
	   	double[] arr = new double[7];
	   	// Cramer's Rule to solve system of equation ( 2 x 2 )
	   	if (x1 - x2 != 0)
	   	{
	   		// y = ax + b
		    	arr[0] = (double)(y1 - y2) / (double)(x1 - x2);
		    	arr[1] = (double)(x1*y2 - y1*x2) / (double)(x1 - x2);
		    	arr[2] = 0;
	   	}
	   	else
	   	{
	   		// line equation based on x = ay + b
	   		arr[0] = 0;
	   		arr[1] = x1;
	   		arr[2] = 1;
	   	}
	   	if (x1 < x2)
	   	{
	   		arr[3] = x1;
	   		arr[5] = x2;
	   		arr[4] = y1;
	   		arr[6] = y2;
	   	}
	   	else if (x1 > x2)
	   	{
	   		arr[3] = x2;
	   		arr[5] = x1;
	   		arr[4] = y2;
	   		arr[6] = y1;
	   	}
	   	else if (x1 == x2)
	   	{
	   		if (y1 < y2)
	   		{
	   			arr[3] = x1;
	       		arr[5] = x2;
	       		arr[4] = y1;
	       		arr[6] = y2;
	   		}
	   		else
	   		{
	   			arr[3] = x2;
	       		arr[5] = x1;
	       		arr[4] = y2;
	       		arr[6] = y1;
	   		}
	   	}
	    	return arr;
   }