MLE of the Kent distribution | R Documentation |
It estimates the concentration and the ovalness parameter of some directional data assuming the Kent distribution. The mean direction and major and minor axes are also estimated.
kent.mle(x)
x |
A matrix containing spherical data in Euclidean coordinates. |
The Kent distribution is fitted to some data and its parameters are estimated.
A list including:
runtime |
The run time of the procedure. |
G |
A 3 x 3 matrix whose first column is the mean direction. The second and third columns are the major and minor axes respectively. |
param |
A vector with the concentration |
logcon |
The logarithm of the normalising constant, using the third type approximation (Kume and Wood, 2005). |
loglik |
The value of the log-likelihood. |
Michail Tsagris.
R implementation and documentation: Michail Tsagris mtsagris@uoc.gr and Giorgos Athineou <gioathineou@gmail.com>.
Kent John (1982). The Fisher-Bingham distribution on the sphere. Journal of the Royal Statistical Society, Series B, 44(1): 71–80.
Kume Alfred and Wood Andrew T.A. (2005). Saddlepoint approximations for the Bingham and Fisher-Bingham normalizing constants. Biometrika, 92(2):465–476
kent.mle, fb.saddle, vmf.mle, wood.mle, sphereplot
x <- rvmf(200, rnorm(3), 15)
kent.mle(x)
vmf.mle(x)
A <- diag( c(-5, 0, 5) )
x <- rfb(200, 15, rnorm(3), A)
kent.mle(x)
vmf.mle(x)
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.