[R] A model for possibly periodic data with varying amplitude [repost, much edited]

[Dieter Menne]

Andrew Robinson <A.Robinson <at> ms.unimelb.edu.au> writes:

> I have up to 12 measures of a protein for each of 6 patients, taken
> every two or three days. The pattern of the protein looks periodic,
> but the height of the peaks is highly variable.  I'm testing for
> periodicity using a Monte Carlo simulation envelope approach applied
> to a cumulative periodogram.  Now I want to predict the location of
> the peaks in time.  Of course, the peaks might be occurring on
> unmeasured days.

Have you checked one of the methods in Chapter 13. of MASS to obtain a smoothed
estimate?

Dieter