converts autoregressive parameters into AR polymials 
 Multiple polynomials can be converted. 
 function  [A] = ar2poly(AR);

  INPUT:
 AR     AR parameters, each row represents one set of AR parameters

  OUTPUT
 A     denominator polynom


 see also ACOVF ACORF DURLEV RC2AR FILTER FREQZ ZPLANE
 
 REFERENCES:
  P.J. Brockwell and R. A. Davis "Time Series: Theory and Methods", 2nd ed. Springer, 1991.
  S. Haykin "Adaptive Filter Theory" 3rd ed. Prentice Hall, 1996.
  M.B. Priestley "Spectral Analysis and Time Series" Academic Press, 1981. 
  W.S. Wei "Time Series Analysis" Addison Wesley, 1990.

Package: tsa