function issosflag = issos(f)
%ISSOS  Determine if filter is composed of second-order sections.
%   FLAG = ISSOS(F) determines if the filter object F is has
%   second-order sections and returns 1 if true and 0 if false.

%   Author(s): R. Losada
%   Copyright 1988-2000 The MathWorks, Inc.
%   $Revision: 1.2 $  $Date: 2000/06/13 21:20:18 $ 

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

issosflag = 1; % Initialized assuming sos
n = 1;

while issosflag & n <= nsections(f),
    fsec = section(f,n);

    issosflag = issos(fsec);
        
    n = n + 1;
end
    
