4.8.10. statsmodels.tsa.varma_process

Helper and filter functions for VAR and VARMA, and basic VAR class

Created on Mon Jan 11 11:04:23 2010 Author: josef-pktd License: BSD

This is a new version, I didn’t look at the old version again, but similar ideas.

not copied/cleaned yet:
  • fftn based filtering, creating samples with fft
  • Tests: I ran examples but did not convert them to tests examples look good for parameter estimate and forecast, and filter functions

main TODOs: * result statistics * see whether Bayesian dummy observation can be included without changing

the single call to linalg.lstsq
  • impulse response function does not treat correlation, see Hamilton and jplv

Extensions * constraints, Bayesian priors/penalization * Error Correction Form and Cointegration * Factor Models Stock-Watson, ???

see also VAR section in Notes.txt

4.8.10.1. Functions

ar2full(ar) make reduced lagpolynomial into a right side lagpoly array
ar2lhs(ar) convert full (rhs) lagpolynomial into a reduced, left side lagpoly array
lagmat(x, maxlag[, trim, original]) create 2d array of lags
padone(x[, front, back, axis, fillvalue]) pad with zeros along one axis, currently only axis=0
trimone(x[, front, back, axis]) trim number of array elements along one axis
varfilter(x, a) apply an autoregressive filter to a series x
vargenerate(ar, u[, initvalues]) generate an VAR process with errors u
varinversefilter(ar, nobs[, version]) creates inverse ar filter (MA representation) recursively

4.8.10.2. Classes

VarmaPoly(ar[, ma]) class to keep track of Varma polynomial format