A Study of Analytic Method for Distortion of Rotational Shape by Using Elliptic Circularity

In this paper, we present a method to evaluate earthenware having a rotational shape by using ellipses. The rotational shape is a typical shape that is encountered in the archeological study of earthenware. The distortion in this shape differs according to the habits and methods of the craftsman. Through calculating the degree of the circularity of the cross sections of a model, the distortion in the shape of the surfaces can be extracted. By using the information thus obtained, earthenware can be classified and evaluated.