public static void gaussSeidel(double[][] A, double[] b){
        boolean stop = false;

        double[] xNew = new double[b.length];
        double[] xOld = new double[b.length];
        double sum = 0.0;
        double sum1 = 0.0;

        do{
            for(int i = 0; i < A.length; i++){
                for(int j = 0; j < A.length; j++){

                    if( j != i)
                        sum += (A[i][j]*xOld[j]);

                    sum1 += (A[i][j]*xNew[j]);
                }

                xNew[i] = (b[i] - sum - sum1)*(1/A[i][i]);
                System.out.println("X" + (i+1) + ": " + xNew[i]);
                System.out.println("");

                if(Math.abs(xNew[i] - xOld[i]) > 0.001){
                     xNew[i] = xOld[i];
                    //System.out.println("NEW :" +  Arrays.toString(xNew));
                    //System.out.println("OLD : " + Arrays.toString(xOld));
                } else{
                    stop = true;}
            }
        }while( !stop);
    }