Circular data and it's application to sequential tests

The aim of this study is to introduce the properties of circular data, to describe the differences between statistical techniques in circular data and linear data, and to investigate the usage of sequential tests in circular statistics. In the study, the properties of circular data is investigated, interrelations between different units of circular measurements is described, circular data display techniques and calculation of descriptive statistics for circular data are explained via examples. The probability distributions in circular data analysis is given and von Mises distribution is examined in detail. Furthermore, mean direction tests for circular data is described and the test of mean direction for von Mises distribution is introduced. The theoretical details, operating characteristic function and average sample number function of Sequential Probability Ratio Test is investigated in detail. Also, sequential test processes for von Mises distributed populations are given. The applications of the techniques by simulation are given. Then, a real life example is shown using the wind directions on Anadolu University airport, obtained from Anadolu University School of Civil Aviation Airfield Meteorology Station Administration. The results obtained by applying wind directions data to the sequential tests for circular data is explained and interpretation of how to use these tests is given.Keywords: Circular Data, Von Mises Distribution, Sequential Tests.