Hi! I am new to R and was wondering if anyone had any helpful information on how to implement seasonal effects of an epidemic into my model. I have seen some models use sin and cosine functions but I have been struggling to understand how I would implement that. I currently have code where the parameters change based on the season but it does not make for the prettiest model. I also was wondering if anyone knew a good way to convert my current model to be used with the Epimodel package. Thank you very much any resources or tips would be great.