cayley.kappa {rotations} | R Documentation |
Return the concentration parameter that corresponds to a given circular variance.
cayley.kappa(nu)
nu |
circular variance |
The concentration parameter \kappa
does not translate across circular
distributions. A commonly used measure of spread in circular distributions
that does translate is the circular variance defined as
\nu=1-E[\cos(r)]
where E[\cos(r)]
is
the mean resultant length. See mardia2000 for more details. This
function translates the circular variance \nu
into the corresponding
concentration parameter \kappa
for the Cayley distribution.
mardia2000
Concentration parameter corresponding to nu.
# Find the concentration parameter for circular variances 0.25, 0.5, 0.75
cayley.kappa(0.25)
cayley.kappa(0.5)
cayley.kappa(0.75)