Circular Statistics for Directional Analysis

Directional distributions do not easily fit into linear frameworks as they involve recurrent patterns and periodic phenomena. They apply to general orientations such as compass directions, as well as to days of the week, seasonality, etc.

Uses

• make inferences about probability density functions p(x) that can be "wrapped" around the circumference of a circle of unit radius
• test for mean direction (single population)
• comparing mean directions (multiple populations)

How this is done

• center of a distribution (directional mean)
• circular distance and measure of dispersion
• higher circular moments
• Raleigh's Test
• Watson's U Test