revGumbel: "Reverse" Gumbel Distribution Functions In plgraphics: User Oriented Plotting Functions

 prevgumbel R Documentation

"Reverse" Gumbel Distribution Functions

Description

Density, distribution function, quantile function and random generation for the “Reverse” Gumbel distribution with parameters `location` and `scale`.

Usage

``````drevgumbel (x, location = 0, scale = 1)
prevgumbel (q, location = 0, scale = 1)
qrevgumbel (p, location = 0, scale = 1)
rrevgumbel (n, location = 0, scale = 1)
``````

Arguments

 `x, q` numeric vector of abscissa (or quantile) values at which to evaluate the density or distribution function. `p` numeric vector of probabilities at which to evaluate the quantile function. `location` location of the distribution `scale` scale (`> 0`) of the distribution. `n` number of random variates, i.e., `length` of resulting vector of `rrevgumbel(..)`.

Value

a numeric vector, of the same length as `x`, `q`, or `p` for the first three functions, and of length `n` for `rrevgumbel()`.

Author(s)

Werner A. Stahel; partly inspired by package VGAM. Martin Maechler for numeric cosmetic.

the `Weibull` distribution functions in R's stats package.

Examples

``````curve(prevgumbel(x, scale= 1/2), -3,2, n=1001, col=1, lwd=2,
main = "revgumbel(x, scale = 1/2)")
abline(h=0:1, v = 0, lty=3, col = "gray30")
curve(drevgumbel(x, scale= 1/2),       n=1001, add=TRUE,
col = (col.d <- adjustcolor(2, 0.5)), lwd=3)
legend("left", c("cdf","pdf"), col=c("black", col.d), lwd=2:3, bty="n")

med <- qrevgumbel(0.5, scale=1/2)
cat("The median is:",  format(med),"\n")
``````

plgraphics documentation built on Oct. 19, 2023, 3 p.m.