lpcrand

 generate n random stable polynomials of order p with a minimum pole
 bandwidth of bw*fs where fs is the sampling fequency.
 To limit the pole radius to r set bw=-log(r)/pi
 bw may be a vector specifying a different max bandwidth for each row

0001 function ar=lpcrand(p,n,bw)
0002 % generate n random stable polynomials of order p with a minimum pole
0003 % bandwidth of bw*fs where fs is the sampling fequency.
0004 % To limit the pole radius to r set bw=-log(r)/pi
0005 % bw may be a vector specifying a different max bandwidth for each row
0006 
0007 %      Copyright (C) Mike Brookes 1997
0008 %      Version: $Id: lpcrand.m 713 2011-10-16 14:45:43Z dmb $
0009 %
0010 %   VOICEBOX is a MATLAB toolbox for speech processing.
0011 %   Home page: http://www.ee.ic.ac.uk/hp/staff/dmb/voicebox/voicebox.html
0012 %
0013 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
0014 %   This program is free software; you can redistribute it and/or modify
0015 %   it under the terms of the GNU General Public License as published by
0016 %   the Free Software Foundation; either version 2 of the License, or
0017 %   (at your option) any later version.
0018 %
0019 %   This program is distributed in the hope that it will be useful,
0020 %   but WITHOUT ANY WARRANTY; without even the implied warranty of
0021 %   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
0022 %   GNU General Public License for more details.
0023 %
0024 %   You can obtain a copy of the GNU General Public License from
0025 %   http://www.gnu.org/copyleft/gpl.html or by writing to
0026 %   Free Software Foundation, Inc.,675 Mass Ave, Cambridge, MA 02139, USA.
0027 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
0028 
0029 if nargin < 3
0030    bw=0;
0031    if nargin < 2
0032       n=1;
0033    end
0034 end 
0035 if p
0036    if ~bw
0037       ar=lpcrf2ar(2*rand(n,p+1)-1);
0038    else
0039       k=exp(-pi*bw(:)*(0:p));
0040       if size(k,1)==1
0041          ar=lpcrf2ar(2*rand(n,p+1)-1).*k(ones(n,1),:);
0042       else
0043          ar=lpcrf2ar(2*rand(n,p+1)-1).*k;
0044       end
0045    end
0046 else
0047    ar=ones(n,1);
0048 end