www.gusucode.com > signal 工具箱matlab源码程序 > signal/@dfilt/@latticemamin/thisnstates.m
function n = thisnstates(Hd) %NSTATES Number of states in discrete-time filter. % NSTATES(Hd) returns the number of states in the % discrete-time filter Hd. The number of states depends on the filter % structure and the coefficients. % % See also DFILT. % Author: Thomas A. Bryan % Copyright 1988-2005 The MathWorks, Inc. n = Hd.ncoeffs; if isempty(n), n=0; else n=n(1); end % If ncoeffs defauls to [], don't have nstates return a negative value. if n < 0, n = 0; end