snorm {VGAM} | R Documentation

## Skew-Normal Distribution

### Description

Density and random generation for the skew-normal distribution.

### Usage

    dsnorm(x, location = 0, scale = 1, shape = 0, log = FALSE)
    rsnorm(n, location = 0, scale = 1, shape = 0)

### Arguments

`x` | vector of quantiles.
`n` | number of observations. Must be a single positive integer.
`location` | The location parameter xi. A vector.
`scale` | The scale parameter w. A positive vector.
`shape` | The shape parameter. It is called alpha in `skewnormal1`.
`log` | Logical. If `log=TRUE` then the logarithm of the density is returned.

### Details

See `skewnormal1`, which currently only estimates the shape parameter. More generally here, Z = xi + w * Y where Y has a standard skew-normal distribution (see `skewnormal1`), xi is the location parameter and w is the scale parameter.

### Value

`dsnorm` gives the density, `rsnorm` generates random deviates.

### Note

The default values of all three parameters corresponds to the skew-normal being the standard normal distribution.

### Author(s)

T. W. Yee

### References

http://tango.stat.unipd.it/SN.

### See Also

`skewnormal1`.

### Examples

    ## Not run:
    n = 200   # grid resolution
    shape = 7
    x = seq(-4, 4, len=n)
    plot(x, dsnorm(x, shape=shape), type="l", col="blue", las=1, ylab="")
    abline(v=0, h=0, lty="dashed", col="darkgreen")
    lines(x, dnorm(x), col="red")
    legend(-3.5, 0.6, leg=c(paste("Blue=dsnorm(x, ", shape,")", sep=""),
           "standard normal density"), lty=1, col=c("blue","red"))
    ## End(Not run)

[Package VGAM version 0.7-9 Index]