www.gusucode.com > signal 工具箱matlab源码程序 > signal/@dfilt/@delay/iirxform.m
function [Ht, anum, aden] = iirxform(Ho,fun,varargin) %IIRXFORM IIR Transformations. % Author(s): R. Losada % Copyright 2005-2006 The MathWorks, Inc. % This should be private [b, a] = tf(Ho); [num, den, anum, aden] = feval(fun, b, a, varargin{:}); % Create the transformed and allpass filters if isreal(num), if sign(num(end)) == sign(den(1)), Ht = dfilt.allpass(den(2:end)); else % Coefficients are negative of each other, account for that Ht = cascade(dfilt.scalar(-1),dfilt.allpass(den(2:end))); end else % Complex case; cannot use dfilt.allpass Ht = dfilt.df2(num,den); end % [EOF]