frechet {evd} R Documentation

## The Frechet Distribution

### Description

Density function, distribution function, quantile function and random generation for the Frechet distribution with location, scale and shape parameters.

### Usage

```dfrechet(x, loc=0, scale=1, shape=1, log = FALSE)
pfrechet(q, loc=0, scale=1, shape=1, lower.tail = TRUE)
qfrechet(p, loc=0, scale=1, shape=1, lower.tail = TRUE)
rfrechet(n, loc=0, scale=1, shape=1)
```

### Arguments

 `x, q` Vector of quantiles. `p` Vector of probabilities. `n` Number of observations. `loc, scale, shape` Location, scale and shape parameters (can be given as vectors). `log` Logical; if `TRUE`, the log density is returned. `lower.tail` Logical; if `TRUE` (default), probabilities are P[X <= x], otherwise, P[X > x]

### Details

The Frechet distribution function with parameters `loc` = a, `scale` = b and `shape` = s is

G(x) = exp{-[(z-a)/b]^(-s)}

for z > a and zero otherwise, where b > 0 and s > 0.

### Value

`dfrechet` gives the density function, `pfrechet` gives the distribution function, `qfrechet` gives the quantile function, and `rfrechet` generates random deviates.

`rgev`, `rgumbel`, `rrweibull`

### Examples

```dfrechet(2:4, 1, 0.5, 0.8)
pfrechet(2:4, 1, 0.5, 0.8)
qfrechet(seq(0.9, 0.6, -0.1), 2, 0.5, 0.8)
rfrechet(6, 1, 0.5, 0.8)
p <- (1:9)/10
pfrechet(qfrechet(p, 1, 2, 0.8), 1, 2, 0.8)
## [1] 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
```

[Package evd version 2.2-4 Index]