Natural Frequency - dindindon, thanks for you reply. I have a couple of questions:
Will an outside force "resonance" only effect amplitude of natural frequency or can it also effect periodicity?
Ampitude is clear as in the example of the Draghi comments. it is also clear that, for example, one might see a low driven by "news" which is a lower low than a cycle low which occurs a few bars later or sooner. In this case would one normally expect to see a cycle re-set itself with this news driven low as the new low or will the cycle ignore this event and continue from the cyclical but higher low? Empirically I have seen what appear to be case of both these options.