TECHNIQUES FOR DIRECTIONAL DATA

Abstract : Statistical data in the form of directions may be recorded as two- or three-dimensional unit vectors from an origin O to points P on the circumference of a circle or the surface of a sphere. In recent years techniques have been developed to deal with such data, when the vectors are directed, i.e., have a preferred sense. This paper shows how the techniques may be adopted for use with axial data, i.e., vectors with no preferred sense, and also for bimodal directed data. Several practical illustrations are given.