# acf_supIG: Autocorrelation function of the supIG trawl function In trawl: Estimation and Simulation of Trawl Processes

## Description

This function computes the autocorrelation function associated with the supIG trawl function.

## Usage

 `1` ```acf_supIG(x, delta, gamma) ```

## Arguments

 `x` The argument (lag) at which the autocorrelation function associated with the supIG trawl function will be evaluated `delta` parameter in the supIG trawl `gamma` parameter in the supIG trawl

## Details

The trawl function is parametrised by the two parameters δ ≥q 0 and γ ≥q 0 as follows:

g(x) = (1-2xγ^{-2})^{-1/2}\exp(δ γ(1-(1-2xγ^{-2})^{1/2})), \mbox{ for } x ≤ 0.

It is assumed that δ and γ are not simultaneously equal to zero. Its autocorrelation function is given by:

r(x) = \exp(δγ (1-√{1+2 x/γ^2})), \mbox{ for } x ≥ 0.

## Value

The autocorrelation function of the supIG trawl function evaluated at x

## Examples

 ```1 2 3 4``` ```#Evaluate the trawl autocorrelation function at x=1 acf_supIG(1,0.3,0.1) #Plot the trawl autocorrelation function plot(acf_supIG((0:10),0.3,0.1)) ```

trawl documentation built on Aug. 16, 2018, 5:04 p.m.