| Contour plot (on the sphere) of a mixture of von Mises-Fisher distributions {Directional} | R Documentation |
Contour plot (on the sphere) of a mixture of von Mises-Fisher distributions
Description
The contour plot (on the sphere) of a mixture of von Mises-Fisher distributions is produced.
Usage
spher.mixvmf.contour(probs, mu, k, bgcol = "snow", dat = NULL, col = NULL,
lat = 50, long = 50)
Arguments
probs |
This is avector with the mixing probability of each group. |
mu |
A matrix with the mean direction of each group. |
k |
A vector with the concentration parameter of each group. |
bgcol |
The color of the surface of the sphere. |
dat |
If you have you want to plot supply them here. This has to be a numerical matrix with three columns, i.e. unit vectors. |
col |
If you supplied data then choose the color of the points. If you did not choose a color, the points will appear in red. |
lat |
A positive number determing the range of degrees to move left and right from the latitude center. See the example to better understand this argument. |
long |
A positive number determing the range of degrees to move up and down from the longitude center. See the example to better understand this argument. |
Details
The goal of this function is for the user to see how the mixtures of von Mises-Fisher look like.
Value
A plot containing the contours of the mixture distribution.
Author(s)
Michail Tsagris.
R implementation and documentation: Michail Tsagris mtsagris@uoc.gr.
References
Kurt Hornik and Bettina Grun (2014). movMF: An R Package for Fitting Mixtures of von Mises-Fisher Distributions http://cran.r-project.org/web/packages/movMF/vignettes/movMF.pdf
Mardia K. V. and Jupp, P. E. (2000). Directional statistics. Chicester: John Wiley & Sons.
Sra S. (2012). A short note on parameter approximation for von Mises-Fisher distributions:
and a fast implementation of I_s(x). Computational Statistics, 27(1): 177–190.
See Also
spher.esag.contour, spher.vmf.contour, mixvmf.mle
Examples
k <- runif(3, 4, 20)
probs <- c(0.2, 0.5, 0.3)
mu <- matrix(rnorm(9, 0, 0.5), ncol = 3)
mu <- mu / sqrt( rowSums(mu^2) )
## the lat and long are decreased to 10. Increase them back to 50 to
## see the difference
spher.mixvmf.contour(probs, mu, k, lat = 10, long = 10)