Abstract
This paper discusses the statistical method for directional orientation data. The results are summerized as follows.
The normal orientation probability paper based on “von Mises” probability density function is usefull to analyze two dimensional directional orientation data and enables us to estimate statistical measures of directional orientation data on paper. Further, the normal orientation probability paper can be applied to statistical analyses of three dimensional directional orientation data. It becomes possible to decompose each average orientation of bimodal orientation data which distribute around two centers. After all, mean directions as average orientations and confidence limits are estimated from distribution groups by using normal orientation probability paper.
