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Directional (version 6.7)

MLE of the ESAG distribution: MLE of the ESAG distribution

Description

MLE of the ESAG distribution.

Usage

esag.mle(y, full = FALSE, tol = 1e-06)

Value

A list including:

mu

The mean vector in \(R^3\).

gam

The two \(\gamma\) parameters.

loglik

The log-likelihood value.

vinv

The inverse of the covariance matrix. It is returned if the argument "full" is TRUE.

rho

The \(rho\) parameter (smallest eigenvalue of the covariance matrix). It is returned if the argument "full" is TRUE.

psi

The angle of rotation \(\psi\) set this equal to TRUE. It is returned if the argument "full" is TRUE.

iag.loglik

The log-likelihood value of the isotropic angular Gaussian distribution. That is, the projected normal distribution which is rotationally symmetric.

Arguments

y

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

full

If you want some extra information, the inverse of the covariance matrix, the \(rho\) parameter (smallest eigenvalue of the covariance matrix) and the angle of rotation \(\psi\), set this equal to TRUE. Otherwise leave it FALSE.

tol

A tolerance value to stop performing successive optimizations.

Author

Michail Tsagris.

R implementation and documentation: Michail Tsagris mtsagris@uoc.gr.

Details

MLE of the MLE of the ESAG distributiontribution, on the sphere, is implemented. ESAG stands for Elliptically Symmetric Angular Gaussian and it was suugested by Paine et al. (2018). Unlike the projected normal distribution this is rotationally symmetric and is a competitor of the spherical Kent distribution (which is also elliptically symmetric).

References

Paine P.J., Preston S.P., Tsagris M. and Wood A.T.A. (2018). An Elliptically Symmetric Angular Gaussian Distribution. Statistics and Computing, 28(3):689--697.

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

See Also

desag, resag, iag.mle, kent.mle, acg.mle, circ.summary, sphereplot

Examples

Run this code
m <- colMeans( as.matrix( iris[,1:3] ) )
y <- resag(1000, m, c(1,0.5) )
esag.mle(y)

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