von Mises-Fisher Distribution

Density and random generation for the spherical normal distribution with mean and concentration parameter (\(\kappa\)) .

Usage

rvmf(
  n = 100,
  mu = Vec3(1, 0, 0),
  k = 5,
  method = c("geologyGeometry", "rotasym")
)

dvmf(x, mu, k = 5)

Source

Adapted fom rotasym::r_vMF() and rotasym::d_vMF(), and geologyGeometry by Davis, J.R.

Arguments

n

integer. number of random samples to be generated

mu

Mean vector. object of class "Vec3", "Line", "Ray", or "Plane", where the rows are the observations and the columns are the coordinates.

k

numeric. The concentration parameter (\(\kappa\)) of the von Mises-Fisher distribution

method

character. Algorithm to generate random vectors from a Fisher distribution. Either "geologyGeometry" (the default) to pick the rayFisher() algorithm from the geologyGeometry code compilation, or "rotasym" to pick the rotasym::r_vMF() algorithm from the rotasym package.

x

object of class "Vec3", "Line", "Ray", or "Plane", where the rows are the observations and the columns are the coordinates.

See also

Other random: rbing, rfb(), rkent(), rrot(), runif.spherical(), rwatson()

Examples

set.seed(20250411)
x <- rvmf(100, mu = Ray(120, 50), k = 5)
contour(x)
points(x)


dx <- dvmf(x, mu = Ray(120, 50))
head(dx)
#>            [,1]
#> [1,] 0.65684755
#> [2,] 0.14268609
#> [3,] 0.34589805
#> [4,] 0.05253657
#> [5,] 0.67050140
#> [6,] 0.18688448

plot(x, col = assign_col(dx))