www.gusucode.com > signal 工具箱matlab源码程序 > signal/@dfilt/@abstractfilter/ziexpand.m
function zi = ziexpand(Hd,x,zi) %ZIEXPAND Expand initial conditions for multiple channels when necessary % ZI = ZIEXPAND(Hd, X, ZI) % % This function is intended to only be used by SUPER_FILTER to expand initial % conditions. % % This should be a private method. % Author: Thomas A. Bryan, R. Losada % Copyright 1988-2004 The MathWorks, Inc. narginchk(3,3); [m,ndata] = size(x); ndata = max(ndata,1); if ~(isempty(zi) | any(size(zi,2) == [ndata,1])), error(message('signal:dfilt:abstractfilter:ziexpand:InvalidDimensions')); end if size(zi,2) == 1 && ndata ~= 1, % Don't enter if ndata=1 because an unnecessary copy of the states is % made zi = zi(:,ones(1,ndata)); end