dLW function

The Log-Weibull distribution

Density, distribution function, quantile function, random generation and hazard function for the Log-Weibull distribution with parameters mu and sigma.

dLW(x, mu, sigma, log = FALSE)

pLW(q, mu, sigma, lower.tail = TRUE, log.p = FALSE)

qLW(p, mu, sigma, lower.tail = TRUE, log.p = FALSE)

rLW(n, mu, sigma)

hLW(x, mu, sigma)

Arguments

• x, q: vector of quantiles.
• mu: parameter.
• sigma: parameter.
• log, log.p: logical; if TRUE, probabilities p are given as log(p).
• lower.tail: logical; if TRUE (default), probabilities are P[X <= x], otherwise, P[X > x].
• p: vector of probabilities.
• n: number of observations.

Returns

dLW gives the density, pLW gives the distribution function, qLW gives the quantile function, rLW

generates random deviates and hLW gives the hazard function.

Details

The Log-Weibull Distribution with parameters mu

and sigma has density given by

$f(y)=(1/\sigma) e^{((y - \mu)/\sigma)} exp\{-e^{((y - \mu)/\sigma)}\},$

for - infty < y < infty.

Examples

old_par <- par(mfrow = c(1, 1)) # save previous graphical parameters

## The probability density function
curve(dLW(x, mu=0, sigma=1.5), from=-8, to=5,
      col="red", las=1, ylab="f(x)")

## The cumulative distribution and the Reliability function
par(mfrow=c(1, 2))
curve(pLW(x, mu=0, sigma=1.5),
      from=-8, to=5,  col="red", las=1, ylab="F(x)")
curve(pLW(x, mu=0, sigma=1.5, lower.tail=FALSE),
      from=-8, to=5, col="red", las=1, ylab="R(x)")

## The quantile function
p <- seq(from=0, to=0.99999, length.out=100)
plot(x=qLW(p, mu=0, sigma=1.5), y=p, xlab="Quantile",
     las=1, ylab="Probability")
curve(pLW(x, mu=0, sigma=1.5), from=-8, to=5, add=TRUE, col="red")

## The random function
hist(rLW(n=10000, mu=0, sigma=1.5), freq=FALSE,
     xlab="x", las=1, main="")
curve(dLW(x, mu=0, sigma=1.5), from=-15, to=6, add=TRUE, col="red")

## The Hazard function
par(mfrow=c(1,1))
curve(hLW(x, mu=0, sigma=1.5), from=-8, to=7,
      col="red", ylab="Hazard function", las=1)

par(old_par) # restore previous graphical parameters

References

Rdpack::insert_ref(key="almalki2014modifications",package="RelDists")

Rdpack::insert_ref(key="Gumbel1958",package="RelDists")

Author(s)

Amylkar Urrea Montoya, amylkar.urrea@udea.edu.co