I would like to identify the x-value of a spectral density plot produced using spec.pgram. Is there such a thing? Can you pass it over to another package? thanks Stephen Sefick -- Let's not spend our time and resources thinking about things that are so little or so large that all they really do for us is puff us up and make us feel like gods. We are mammals, and have not exhausted the annoying little problems of being mammals. -K. Mullis