dfdsimsp.m

AFD - Advanced Filter Design using MATLABMiroslav D. Lutovac, Dejan V. Tosicversion 1.00 released 15

function simspec = dfdsimsp(spec)

% adfsimsp.m  DFD Simetric spec
% 23:55  8/3/99
%
%   Authors: Dejan V. Tosic, Miroslav D. Lutovac, 1999.03.08
%                 [e-mail]
%                 [e-mail]
%
%   Copyright (c) 1999 by Tosic & Lutovac
%   $Revision: 1.0 $  $Date: 1999/03/08 03:07:42 $
%
%   References:
%        Miroslav D. Lutovac, Dejan V. Tosic, Brian L. Evans
%           Advanced Filter Design for Signal Processing
%                   Using MATLAB and Mathematica

simspec = spec;

if tan(pi*spec(1)) * tan(pi*spec(4)) > tan(pi*spec(2)) * tan(pi*spec(3))
  simspec(4) = atan(tan(pi*spec(2)) * tan(pi*spec(3)) ...
               / tan(pi*spec(1)))/pi;
elseif spec(1)*spec(4) < spec(2)*spec(3)
  simspec(1) =  atan(tan(pi*spec(2)) * tan(pi*spec(3)) ...
                / tan(pi*spec(4)))/pi;
end