Sorry for a late reply here, I guess I lost the thread.
I cant recall why I put the question in the headline like that, of course there is a calculation (I had been using it at work), but thx Ajit anyway. What I wanted to discuss is of course whether it is nonsense to do these calculations.
I read somewhere that when you use frequencies over the whole spectrum, it should be okay, because then you have an interval? There was twice as many replying "..." . Or is it still a cover?
Miner, thx, though I am not sure about the nonparametric approach, just calling it that does not legitimate it?