Inverse impulse using the Levinson-Durbin algorithm syntax inv=invimplms(den,n,d) den - denominator impulse n - length of result d - delay of result inv - inverse impulse response of length n with delay d Levinson-Durbin algorithm from Proakis and Manolokis p.865 Author: Bob Cain, May 1, 2001 arcane[AT]arcanemethods[DOT]com