group.vm: Summary statistics for grouped circular data

In Directional: A Collection of Functions for Directional Data Analysis

Summary statistics for grouped circular data

Description

It produces a few summary measures for grouped circular data.

Usage

group.vm(group, fi, rads = FALSE)

Arguments

group	A matrix denoting the classes. Each row consists of two numbers, the lower and upper points of each class.
fi	The frequency of each class of data.
rads	If the data are in rads, then this should be TRUE, otherwise FALSE.

Details

It returns the circular mean, mean resultant length, variance, standard deviation and concentration parameter. So, basically it returns the estimated values of the parameters of the von Mises distribution. The mena resultant length though is group corrected.

Value

A list including:

mesos	The circular mean direction.
confint	The 95% confidence interval for the circular mean direction.
kappa	The concentration parameter.
MRL	The mean resultant length.
circvariance	The circular variance.
circstd	The circular standard deviation.

Author(s)

Michail Tsagris.

R implementation and documentation: Michail Tsagris [e-mail].

References

Pewsey Arthur, Markus Neuhauser and Graeme D. Ruxton (2013). Circular statistics in R. Oxford University Press.

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

See Also

circ.summary, rvonmises, vm.kde

Examples

x <- rvonmises(200, 3, 10)
a <- circ.summary(x, rads = TRUE, plot = FALSE)
group <- seq(min(x) - 0.1, max(x) + 0.1, length = 6)
y <- cut(x, breaks = group, length = 6)
group <- matrix( c( group[1], rep(group[2:5], each = 2), group[6]), ncol = 2, byrow = TRUE)
fi <- as.vector( table(y) )
b <- group.vm(group, fi, rads = TRUE)
a
b

Directional documentation built on Oct. 30, 2024, 9:15 a.m.