rPGamma {SubTS}R Documentation

Simulation from p-gamma distributions.

Description

Simulates from p-gamma distributions. These are p-RDTS distributions with alpha=0.

Usage

rPGamma(n, t, mu, p, step = 1)

Arguments

n

Number of observations.

t

Parameter >0.

mu

Parameter >0.

p

Parameter >1.

step

Tuning parameter. The larger the step, the slower the rejection sampling, but the fewer the number of terms. See Hoefert (2011) or Section 4 in Grabchak (2019).

Details

Uses Theorem 1 in Grabchak (2021) to simulate from a p-Gamma distribution. This distribution has Laplace transform

L(z) = exp( t int_0^infty (e^(-xz)-1)e^(-(mu*x)^p) x^(-1) dx ), z>0

and Levy measure

M(dx) = t e^(-(mu*x)^p) x^(-1) 1(x>0)dx.

Value

Returns a vector of n random numbers.

Author(s)

Michael Grabchak and Lijuan Cao

References

M. Grabchak (2019). Rejection sampling for tempered Levy processes. Statistics and Computing, 29(3):549-558

M. Grabchak (2021). An exact method for simulating rapidly decreasing tempered stable distributions. Statistics and Probability Letters, 170: Article 109015.

M. Hofert (2011). Sampling exponentially tilted stable distributions. ACM Transactions on Modeling and Computer Simulation, 22(1), 3.

Examples

rPGamma(20, 2, 2, 2)

[Package SubTS version 1.0 Index]