Hello, Plotting values of relative residual norm versus iteration I noticed that these curves have different behavior. For instance, ones I got with BiCGStab are oscillatory and rather noisy with large jumps within few iterations. Curves for QMR are smooth, however it's usual that they stagnate for ~10-20 iterations and then go down further. Same preconditioner is applied for both and both methods are Lanczos based, so I don't understand this. I'm wondering is this just my specific case or there is general explanation for that?
-- Regards, Alexander
