> Since tolb is multiplied with normb^2 the stopping criterion is automatically thought of as relative. More important however: when called from incr_eigcg normb depends on the history of the algorithm.

@florian-burger  I'm not sure I follow the behaviour correctly but I think it's not true that it depends on the history. As far as I can tell, incr_eigcg will call eigcg with flag!=3 only once (i.e. the first time around) and subsequently normb will not be updated and will therefore always correspond to the norm of the *initial* starting vector. Is this correct @amabdelrehim ?