Permutation based 2-sample mean test for (hyper-)spherical data {Directional}

Permutation based 2-sample mean test for (hyper-)spherical data

Description

Permutation based 2-sample mean test for (hyper-)spherical data.

Usage

hcf.perm(x1, x2, B = 999)
lr.perm(x1, x2, B = 999)
hclr.perm(x1, x2, B = 999)
embed.perm(x1, x2, B = 999)
het.perm(x1, x2, B = 999)

Arguments

x1

A matrix with the data in Euclidean coordinates, i.e. unit vectors.

x2

A matrix with the data in Euclidean coordinates, i.e. unit vectors.

B

The number of permutations to perform.

Details

The high concentration (hcf.perm), log-likelihood ratio (lr.perm), high concentration log-likelihood ratio (hclr.perm), embedding approach (embed.perm) or the non equal concentration parameters approach (het.perm) is used.

Value

This is an "htest"class object. Thus it returns a list including:

statistic

The test statistic value.

parameter

The degrees of freedom of the test. Since these are permutation based tests this is "NA".

p.value

The p-value of the test.

alternative

A character with the alternative hypothesis.

method

A character with the test used.

data.name

A character vector with two elements.

Author(s)

Michail Tsagris.

R implementation and documentation: Michail Tsagris [e-mail].

References

Mardia K. V. and Jupp P. E. (2000). Directional statistics. Chicester: John Wiley & Sons.

Rumcheva P. and Presnell B. (2017). An improved test of equality of mean directions for the Langevin-von Mises-Fisher distribution. Australian & New Zealand Journal of Statistics, 59(1), 119–135.

Tsagris M. and Alenazi A. (2024). An investigation of hypothesis testing procedures for circular and spherical mean vectors. Communications in Statistics-Simulation and Computation, 53(3): 1387–1408.

See Also

hcf.boot, hcf.aov, spherconc.test, conc.test

Examples

x <- rvmf(60, rnorm(3), 15)
ina <- rep(1:2, each = 30)
x1 <- x[ina == 1, ]
x2 <- x[ina == 2, ]
hcf.perm(x1, x2)
lr.perm(x1, x2)
het.boot(x1, x2)