di.fun {GWI}

Function for DI

Description

The function computes the univariate Poisson dispersion index for a count random variable.

Usage

di.fun(X)

Arguments

X

A count random variable

Details

di.fun provides the univariate Poisson dispersion index (Fisher, 1934). We can refer to Touré et al. (2020) for more details on the Poisson dispersion index.

Value

Returns

di

The Poisson dispersion index

Author(s)

Aboubacar Y. Touré and Célestin C. Kokonendji

References

Fisher, R.A. (1934). The effects of methods of ascertainment upon the estimation of frequencies, Annals of Eugenics 6, 13-25.

Touré, A.Y., Dossou-Gbété, S. and Kokonendji, C.C. (2020). Asymptotic normality of the test statistics for relative dispersion and relative variation indexes, Journal of Applied Statistics 47, 2479-2491.

Examples

X<-c(6,7,8,9,8,4,7,6,12,8,0)
di.fun(X)
T<-c(61,72,83,94,85,46,77,68,129,80,10,12,12,3,4,5)
di.fun(T)