R: Slash Distribution

Slash {VGAM} | R Documentation

## Slash Distribution

### Description

Density function, distribution function, and random generation for the slash distribution.

### Usage

    dslash(x, mu = 0, sigma = 1, log = FALSE, smallno = .Machine$double.eps*1000)
    pslash(q, mu = 0, sigma = 1, very.negative = -10000,
           lower.tail = TRUE, log.p = FALSE)
    rslash(n, mu = 0, sigma = 1)

### Arguments

`x, q` | vector of quantiles.
`n` | Same as `runif`.
`mu, sigma` | the mean and standard deviation of the univariate normal distribution.
`log` | Logical. If `TRUE` then the logarithm of the density is returned.
`very.negative` | Numeric, of length 1. A large negative value. For `(q-mu)/sigma` values less than this, the value 0 is returned because `integrate` tends to fail. A warning is issued. Similarly, if `(q-mu)/sigma` is greater than `abs(very.negative)` then 1 is returned with a warning.
`smallno` | See `slash`.
`lower.tail, log.p` | Same meaning as in `pnorm` or `qnorm`.

### Details

See `slash`, the VGAM family function for estimating the two parameters by maximum likelihood estimation, for the formula of the probability density function and other details.

Function `pslash` uses a `for ()` loop and `integrate`, meaning it's very slow. It may also be inaccurate for extreme values of `q`, and returns with 1 or 0 values when too extreme compared to `very.negative`.

### Value

`dslash` gives the density, and `pslash` gives the distribution function, `rslash` generates random deviates.

### Note

`pslash` is very slow.

### Author(s)

Thomas W. Yee and C. S. Chee

### See Also

`slash`.

### Examples

    ## Not run:
    curve(dslash, col = "blue", ylab = "f(x)", -5, 5, ylim = c(0, 0.4), las = 1,
         main = "Standard slash, normal and Cauchy densities", lwd = 2)
    curve(dnorm, col = "black", lty = 2, lwd = 2, add = TRUE)
    curve(dcauchy, col = "orange", lty = 3, lwd = 2, add = TRUE)
    legend("topleft", c("slash", "normal", "Cauchy"), lty = 1:3,
           col = c("blue","black","orange"), lwd = 2)

    curve(pslash, col = "blue", -5, 5, ylim = 0:1)
    pslash(c(-Inf, -20000, 20000, Inf))  # Gives a warning

    ## End(Not run)

[Package VGAM version 1.1-3 Index]