function [wp,ws,w0]=dfirlpp(ty,fp,fs,ff)
% FIRLPP

% Author: Ashok Ambardar <akambard@mtu.edu>
% Date: 2/2/96 11:32AM
% Copyright (c) 1997 by Prentice-Hall, Inc.


w0 = 0;
wp = fp/ff;
ws = fs/ff;  % for lp

if ty == 2, % highpass
   wp = pi-wp;
   ws = pi-ws;
end

if ty == 3 | ty == 4,
   ap = abs(diff(fp));
   as = abs(diff(fs));
   dw1 = abs(wp(1)-ws(1));
   dw2 = abs(wp(2)-ws(2));
   dw = min(dw1,dw2);
   if ty == 3,
      w0 = 0.5*(wp(1)+wp(2));
      wp = 0.5*(wp(2)-wp(1));
   else
      w0 = 0.5*(ws(1)+ws(2));
      wp = 0.5*(ws(2)-ws(1));
   end
   ws = wp+dw;
end