English

The distribution of the maximum of a first order moving average: the continuous case

Methodology 2009-09-07 v5 Statistics Theory Statistics Theory

Abstract

We give the distribution of MnM_n, the maximum of a sequence of nn observations from a moving average of order 1. Solutions are first given in terms of repeated integrals and then for the case where the underlying independent random variables have an absolutely continuous density. When the correlation is positive, P(Mn P(M_n %\max^n_{i=1} X_i \leq x) =\ \sum_{j=1}^\infty \beta_{jx} \nu_{jx}^{n} \approx B_{x} \nu_{1x}^{n} where %{Xi}\{X_i\} is a moving average of order 1 with positive correlation, and {νjx}\{\nu_{jx}\} are the eigenvalues (singular values) of a Fredholm kernel and ν1x\nu_{1x} is the eigenvalue of maximum magnitude. A similar result is given when the correlation is negative. The result is analogous to large deviations expansions for estimates, since the maximum need not be standardized to have a limit. % there are more terms, and P(Mn<x)Bx (1+ν1x)n.P(M_n <x) \approx B'_{x}\ (1+\nu_{1x})^n. For the continuous case the integral equations for the left and right eigenfunctions are converted to first order linear differential equations. The eigenvalues satisfy an equation of the form i=1wi(λθi)1=λθ0\sum_{i=1}^\infty w_i(\lambda-\theta_i)^{-1}=\lambda-\theta_0 for certain known weights {wi}\{w_i\} and eigenvalues {θi}\{\theta_i\} of a given matrix. This can be solved by truncating the sum to an increasing number of terms.

Keywords

Cite

@article{arxiv.0802.0523,
  title  = {The distribution of the maximum of a first order moving average: the continuous case},
  author = {Christopher S. Withers and Saralees Nadarajah},
  journal= {arXiv preprint arXiv:0802.0523},
  year   = {2009}
}

Comments

15 A4 pages. Version 4 corrects (3.8). Version 3 expands Section 2. Version 2 corrected recurrence relation (2.5)