sgh {fBasics}R Documentation

Standardized Generalized Hyperbolic Distribution

Description

Density, distribution function, quantile function and random generation for the standardized generalized hyperbolic distribution.

Usage

dsgh(x, zeta = 1, rho = 0, lambda = 1, log = FALSE)
psgh(q, zeta = 1, rho = 0, lambda = 1)
qsgh(p, zeta = 1, rho = 0, lambda = 1)
rsgh(n, zeta = 1, rho = 0, lambda = 1)

Arguments

zeta, rho, lambda

shape parameter zeta is positive, skewness parameter rho is in the range (-1, 1).

log

a logical flag by default FALSE. If TRUE, log values are returned.

n

number of observations.

p

a numeric vector of probabilities.

x, q

a numeric vector of quantiles.

Details

The generator rsgh is based on the GH algorithm given by Scott (2004).

Value

All values for the *sgh functions are numeric vectors: d* returns the density, p* returns the distribution function, q* returns the quantile function, and r* generates random deviates.

All values have attributes named "param" listing the values of the distributional parameters.

Author(s)

Diethelm Wuertz.

Examples

   
## rsgh -
   set.seed(1953)
   r = rsgh(5000, zeta = 1, rho = 0.5, lambda = 1)
   plot(r, type = "l", col = "steelblue",
     main = "gh: zeta=1 rho=0.5 lambda=1")
 
## dsgh - 
   # Plot empirical density and compare with true density:
   hist(r, n = 50, probability = TRUE, border = "white", col = "steelblue",
     ylim = c(0, 0.6))
   x = seq(-5, 5, length = 501)
   lines(x, dsgh(x, zeta = 1, rho = 0.5, lambda = 1))
 
## psgh -  
   # Plot df and compare with true df:
   plot(sort(r), (1:5000/5000), main = "Probability", col = "steelblue")
   lines(x, psgh(x, zeta = 1, rho = 0.5, lambda = 1))
   
## qsgh -
   # Compute Quantiles:
   round(qsgh(psgh(seq(-5, 5, 1), zeta = 1, rho = 0.5), zeta = 1, rho = 0.5), 4)
[Package fBasics version 2160.81 Index]