مرکز منطقه ای اطلاع رساني علوم و فناوري - Directional Data Analysis and An Application

Abstract :

Directional data analysis method is used in the observed values that are obtained angularly. In this technique, every observation obtained as an angular data type is located on the unit circle axis and a mean vector in relation to the data is formed. The statistical computations are obtained through that mean vector. In this study, some of the basic directional statistical methods are aimed to be analyzed. In accordance with this purpose, the angles between teats are measured six times in the mornings before milking the goats during the lactation period. Some directional statistics were obtained from this analysis by these teat angles measurements were analyzed. As a consequence, the length of mean vector increased while the circular variance was decreasing. The lowest variance and the maximum length of the mean vector are obtained in the 6th test milking. In addition, according to the Watson-Williams F test, which is used to determine whether there is a difference between the mean angles, the differences between the mean angles of test milking 5 and 6 are found to be statistically important (p 0.05) and the mean angles decrease through the end of the lactation period.