Newdistns (version 1.0)

expg: Exponentiated G distribution

Description

Computes the pdf, cdf, quantile and random numbers of the exponentiated G distribution due to Gupta et al. (1998) specified by the pdf $$f (x) = a g (x) G^{a - 1} (x)$$ for $G$ any valid cdf, $g$ the corresponding pdf and $a > 0$, the shape parameter.

Usage

dexpg(x, spec, a = 1, log = FALSE, ...)
pexpg(x, spec, a = 1, log.p = FALSE, lower.tail = TRUE, ...)
qexpg(p, spec, a = 1, log.p = FALSE, lower.tail = TRUE, ...)
rexpg(n, spec, a = 1, ...)

Arguments

x

scaler or vector of values at which the pdf or cdf needs to be computed

p

scaler or vector of values at which the quantile needs to be computed

n

number of random numbers to be generated

a

the value of the shape parameter, must be positive, the default is 1

spec

a character string specifying the distribution of G and g (for example, "norm" if G and g correspond to the standard normal).

log

if TRUE then log(pdf) are returned

log.p

if TRUE then log(cdf) are returned and quantiles are computed for exp(p)

lower.tail

if FALSE then 1-cdf are returned and quantiles are computed for 1-p

...

other parameters

Value

• An object of the same length as x, giving the pdf or cdf values computed at x or an object of the same length as p, giving the quantile values computed at p or an object of the same length as n, giving the random numbers generated.

References

S. Nadarajah, Newdistns: An R Package for new families of distributions, submitted R. C. Gupta, P. L. Gupta, R. D. Gupta, Modeling failure time data by Lehman alternatives, Communications in Statistics---Theory and Methods 27 (1998) 887-904

Examples

x=runif(10,min=0,max=1)
dexpg(x,"exp",a=1)
pexpg(x,"exp",a=1)
qexpg(x,"exp",a=1)
rexpg(10,"exp",a=1)