Directional (version 4.0)

Hypothesis test for von Mises-Fisher distribution over Kent distribution: Hypothesis test for von Mises-Fisher distribution over Kent distribution

Description

The null hypothesis is whether a von Mises-Fisher distribution fits the data well, where the altenrative is that Kent distribution is more suitable.

Usage

fishkent(x, B = 999)

Arguments

x

A numeric matrix containing the data as unit vectors in Euclidean coordinates.

B

The number of bootstrap re-samples. By default is set to 999. If it is equal to 1, no bootstrap is performed and the p-value is obtained throught the asymptotic distribution.

Value

A vector including:

test

The value of the test statistic

p-value or Bootstrap p-value

The p-value of the test.

Details

Essentially it is a test of rotational symmetry, whether Kent's ovalness parameter (beta) is equal to zero. This works for spherical data only.

References

Rivest, L. P. (1986). Modified Kent's statistics for testing goodness of fit for the Fisher distribution in small concentrated samples. Statistics & probability letters, 4(1): 1-4.

See Also

iagesag, vmf, kent.mle, rkent

Examples

# NOT RUN {
x <- rvmf(100, rnorm(3), 15)
fishkent(x)
fishkent(x, B = 1)
iagesag(x)
# }