I just read Chapter 3 in "A Multigrid Tutorial" by Briggs/Henson/McCormick, link.
The text is about Multigrid cycles such as V-cycle, mu-cycle, FMG. What caught my eye: In most iterative procedures one checks whether it has converged to the desired tolerance/accuracy and if so, the procedure stops. But Briggs/Henson/McCormick do not use any convergence checking in the presented schemes. The number of iterations and recursions are just hardcoded and one has to trust that the scheme will converge.
So how is this done in Multigrid normally? Is it usual that the number of iterations/recursions is just hardcoded? I really fear that I will either waste a lot of computation time because I'm over-precise or on the other hand, accuracy will be poor in many cases when I choose a lower number of iterations/recursions.