pdfgep {lmomco}R Documentation

Probability Density Function of the Generalized Exponential Poisson Distribution

Description

This function computes the probability density of the Generalized Exponential Poisson distribution given parameters (β\beta, κ\kappa, and hh) computed by pargep. The probability density function is

f(x)=κhη[1exp(h)]κ1exp[h+hexp(ηx)×exp[hηx+hexp(ηx)]\mbox,f(x) = \frac{\kappa h \eta}{[1 - \exp(-h)]^\kappa}{1 - \exp[-h + h\exp(-\eta x)}\times\exp[-h - \eta x + h\exp(-\eta x)]\mbox{,}

where F(x)F(x) is the nonexceedance probability for quantile x>0x > 0, η=1/β\eta = 1/\beta, β>0\beta > 0 is a scale parameter, κ>0\kappa > 0 is a shape parameter, and h>0h > 0 is another shape parameter.

Usage

pdfgep(x, para)

Arguments

x

A real value vector.

para

The parameters from pargep or vec2par.

Value

Probability density (ff) for xx.

Author(s)

W.H. Asquith

References

Barreto-Souza, W., and Cribari-Neto, F., 2009, A generalization of the exponential-Poisson distribution: Statistics and Probability, 79, pp. 2493–2500.

See Also

pdfgep, quagep, lmomgep, pargep

Examples

pdfgep(0.5, vec2par(c(10,2.9,1.5), type="gep"))
## Not run: 
x <- seq(0,3, by=0.01); ylim <- c(0,1.5)
plot(NA,NA, xlim=range(x), ylim=ylim, xlab="x", ylab="f(x)")
mtext("Barreto-Souza and Cribari-Neto (2009, fig. 1)")
K <- c(0.1, 1, 5, 10)
for(i in 1:length(K)) {
   gep <- vec2par(c(2,K[i],1), type="gep"); lines(x, pdfgep(x, gep), lty=i)
}

## End(Not run)

[Package lmomco version 2.5.1 Index]