angleTest: Test whether the direction of two vectors is similar

In zarquon42b/Morpho: Calculations and Visualisations Related to Geometric Morphometrics

Test whether the direction of two vectors is similar

Description

Test whether the direction of two vectors is similar

Usage

angleTest(x, y)

Arguments

x	vector
y	vector

Details

Under the assumption of all (normalized) n-vectors being represented by an n-dimensional hypersphere, the probability of the angle between two vectors is <= the measured values can be estimated as the area of a cap defined by that angle and divided by the hypersphere's complete surface area.

Value

a list with

angle	angle between vectors
p.value	p-value for the probability that the angle between two random vectors is smaller or equal to the one calculatted from x and y

References

S. Li , 2011. Concise Formulas for the Area and Volume of a Hyperspherical Cap. Asian Journal of Mathematics & Statistics, 4: 66-70.

Examples

x <- c(1,0); y <- c(1,1) # for a circle this should give us p = 0.25 as the angle between vectors
##  is pi/4 and for any vector the segment +-pi/4 covers a quarter of the circle 
angleTest(x,y)

zarquon42b/Morpho documentation built on Jan. 28, 2024, 2:11 p.m.