fit_DExptrawl function

Fits the trawl function consisting of the weighted sum of two exponential functions

Fits the trawl function consisting of the weighted sum of two exponential functions

fit_DExptrawl(x, Delta = 1, GMMlag = 5, plotacf = FALSE, lags = 100)

Arguments

  • x: vector of equidistant time series data
  • Delta: interval length of the time grid used in the time series, the default is 1
  • GMMlag: lag length used in the GMM estimation, the default is 5
  • plotacf: binary variable specifying whether or not the empirical and fitted autocorrelation function should be plotted
  • lags: number of lags to be used in the plot of the autocorrelation function

Returns

w: the weight parameter (restricted to be in [0,0.5] for identifiability reasons)

lambda1: the first memory parameter (denoted by λ1\lambda_1 above)

lambda2: the second memory parameter (denoted by λ2\lambda_2

above)

LM: The Lebesgue measure of the trawl set associated with the double exponential trawl

Details

The trawl function is parametrised by the three parameters c("0leq\n0\\leq\n", "wleq1 w \\leq 1") and λ1,λ2>0\lambda_1,\lambda_2 > 0 as follows:

g(x)=weλ1x+(1w)eλ2x,\mboxforx0. g(x) =we^{\lambda_1 x}+(1-w)e^{\lambda_2 x}, \mbox{ for } x \le 0.

The Lebesgue measure of the corresponding trawl set is given by w/λ1+(1w)/λ2w/\lambda_1+(1-w)/\lambda_2.

  • Maintainer: Almut E. D. Veraart
  • License: GPL-3
  • Last published: 2021-02-22

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