Directional (version 7.0)

Summary statistics for grouped circular data: Summary statistics for grouped circular data

Description

It produces a few summary measures for grouped circular data.

Usage

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

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.

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.

Author

Michail Tsagris.

R implementation and documentation: Michail Tsagris .

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.

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