Hello, I'm trying to built a model for a time-series analysis with an periodic term for seasonality. I've tried both harmonic (package spatstat) and periodicSpline (package splines). The former don't allow a periodic constraint, while I've not been able to use the latter within a dataframe with several repetition of the month series along the years. Can you suggest some options or new commands? Thanks a lot Antonio Gasparrini Public and Environmental Health Research Unit (PEHRU) London School of Hygiene & Tropical Medicine Keppel Street, London WC1E 7HT, UK Office: 0044 (0)20 79272406 - Mobile: 0044 (0)79 64925523 www.lshtm.ac.uk/pehru/ [[alternative HTML version deleted]]