double value = 2;
if (dense)
A = Factory2D.dense.sample(size,size, value, nonZeroFraction);
else
A = Factory2D.sparse.sample(size,size, value, nonZeroFraction);
b = A.like1D(size).assign(1);
//A.assign(random);
//A.assign(F.rint); // round
System.out.println("generating invertible matrix...");
Property.generateNonSingular(A);