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Directional (version 6.8)

MLE of the Wood bimodal distribution on the sphere: MLE of the Wood bimodal distribution on the sphere

Description

It estimates the parameters of the Wood bimodal distribution.

Usage

wood.mle(y)

Value

A list including:

info

A 5 x 3 matrix containing the 5 parameters, \(\gamma\), \(\delta\), \(\alpha\), \(\beta\) and \(\kappa\) along with their corresponding 95% confidence intervals all expressed in degrees.

modes

The two axis of the modes of the distribution expressed in degrees.

unitvectors

A 3 x 3 matrix with the 3 unit vectors associated with the \(\gamma\) and \(\delta\) parameters.

loglik

The value of the log-likelihood.

Arguments

y

A matrix containing two columns. The first one is the latitude and the second is the longitude, both expressed in degrees.

Author

Michail Tsagris.

R implementation and documentation: Michail Tsagris mtsagris@uoc.gr and Giorgos Athineou <gioathineou@gmail.com>.

Details

The Wood distribution is fitted to some data and its parameters are estimated. It is a bimodal distribution which contains 5 parameters, just like the Kent distribution.

References

Wood A.T.A. (1982). A bimodal distribution on the sphere. Journal of the Royal Statistical Society, Series C, 31(1): 52--58.

See Also

kent.mle, esag.mle, vmf.mle, sphereplot

Examples

Run this code
x <- rvmf(100, rnorm(3), 15)
x <- euclid.inv(x)
wood.mle(x)

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