Test for equality of concentration parameters for spherical data {Directional}

Test for equality of concentration parameters for spherical data

Description

This tests the equality of concentration parameters for spherical data only.

Usage

spherconc.test(x, ina)

Arguments

x

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

ina

A variable indicating the groupings of the observations.

Details

The test is designed for spherical data only.

Value

A list including:

mess

A message stating the value of the mean resultant and which test statistic was used, U1, U2 or U3.

res

A vector containing the test statistic and its p-value.

Author(s)

Michail Tsagris.

R implementation and documentation: Michail Tsagris [e-mail] and Giorgos Athineou <[e-mail]>.

References

Kanti V. Mardia and Peter E. Jupp. Directional statistics, pg. 226–227.

See Also

het.aov, lr.aov, embed.aov, hcf.aov, conc.test, sphereplot

Examples

x <- rvmf(100, rnorm(3), 15)
ina <- rep(1:4, each = 25)
spherconc.test(x, ina)