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SingleParameterPareto: The Single-parameter Pareto Distribution

Description

Density function, distribution function, quantile function, random generation, raw moments, and limited moments for the Single-parameter Pareto distribution with parameter shape.

Usage

dpareto1(x, shape, min, log = FALSE)
ppareto1(q, shape, min, lower.tail = TRUE, log.p = FALSE)
qpareto1(p, shape, min, lower.tail = TRUE, log.p = FALSE)
rpareto1(n, shape, min)
mpareto1(order, shape, min)
levpareto1(limit, shape, min, order = 1)

Arguments

x, q
vector of quantiles.
p
vector of probabilities.
n
number of observations. If length(n) > 1, the length is taken to be the number required.
shape
parameter. Must be strictly positive.
min
lower bound of the support of the distribution.
log, log.p
logical; if TRUE, probabilities/densities $p$ are returned as $\log(p)$.
lower.tail
logical; if TRUE (default), probabilities are $P[X \le x]$, otherwise, $P[X > x]$.
order
order of the moment.
limit
limit of the loss variable.

Value

  • dpareto1 gives the density, ppareto1 gives the distribution function, qpareto1 gives the quantile function, rpareto1 generates random deviates, mpareto1 gives the $k$th raw moment, and levpareto1 gives the $k$th moment of the limited loss variable.

    Invalid arguments will result in return value NaN, with a warning.

Details

The Single-parameter Pareto distribution with parameter shape $= \alpha$ has density: $$f(x) = \frac{\alpha \theta^\alpha}{x^{\alpha + 1}}$$ for $x > \theta$, $\alpha > 0$ and $\theta > 0$. Although there appears to be two parameters, only shape is a true parameter. The value of min $= \theta$ must be set in advance.

The $k$th raw moment of the random variable $X$ is $E[X^k]$ and the $k$th limited moment at some limit $d$ is $E[\min(X, d)^k]$.

References

Klugman, S. A., Panjer, H. H. and Willmot, G. E. (2004), Loss Models, From Data to Decisions, Second Edition, Wiley.

Examples

Run this code
exp(dpareto1(5, 3, 4, log = TRUE))
p <- (1:10)/10
ppareto1(qpareto1(p, 2, 3), 2, 3)
mpareto1(2, 3, 4) - mpareto(1, 3, 4) ^ 2
levpareto(10, 3, 4, order = 2)

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