Harmonic Analysis of Seasonal Variation with an Application to Hog Production

Abstract

Abstract Several methods for analyzing seasonal variation are available. Most common among these are methods based on moving averages. One serious shortcoming of moving average methods is that the process of moving averages can introduce a fictitious degree of regularity into the seasonal pattern. An alternative method, harmonic analysis, is presented in this paper with an application to hog production data. The investigation illustrates the flexibility of harmonic analysis for measurement of patterns of seasonal variation. Hypotheses concerning changes in amplitude and phasing of the seasonal pattern are tested and a discussion of these procedures is presented.