function isallpassflag = isallpass(f,sec)
%ISALLPASS  Determine if filter object has allpass sections.
%   FLAG = ISALLPASS(F) determines if the filter object F has
%   allpass filter sections, and returns 1 if true and 0 if
%   false.
%
%   FLAG = ISALLPASS(F,I) determines if the I-th section of the
%   filter object F is an allpass section and returns 1 if true
%   and 0 if false.
%
%   Since LATCALLPASS filters always have allpass sections, this
%   function always returns one.
%
%   See also DFILT/ISMINPHASE, DFILT/ISMAXPHASE, DFILT/ISLINPHASE,
%   DFILT/ISFIR, DFILT/ISSTABLE.

%   Author(s): R. Losada
%   Copyright 1988-2000 The MathWorks, Inc.
%   $Revision: 1.2 $  $Date: 2000/06/13 21:21:50 $ 

error(nargchk(1,2,nargin));

if nargin == 2,
    f = section(f,sec);
end

isallpassflag = 1; 