code: public static double calculateScaledResidual(double[][] A, double[] x, double[] b){
  		DoubleMatrix2D AMatrix = DoubleFactory2D.dense.make(A); 
  		DoubleMatrix1D xVector = DoubleFactory1D.dense.make(x);
  		DoubleMatrix1D bVector = DoubleFactory1D.dense.make(b);
  		return calculateScaledResidual(AMatrix, xVector, bVector);
  	}
docs: Calculate the scaled residual
  <br> ||Ax-b||_oo/( ||A||_oo . ||x||_oo + ||b||_oo ), with
  <br> ||x||_oo = max(||x[i]||)