function plotbasisfuns(p,n)
% FUNCTION:     plotbasisfuns                Part of DPWT Toolbox
%
% SYNOPSIS:     plotbasisfuns(P,N)
%
% DESCRIPTION:  Plot representative basis sequences for the DPWT
%               basis using a Daubechies wavelet filter of length 2*N
%               for sequences of length 2^P. The level number is printed
%               above each basis function. Only the first basis element
%               is shown for each level.

% AUTHOR:	Neil Getz
% DATE:		3-30-94

if(nargin<2),
   help plotbasisfuns,
   return;
end

rows = floor(sqrt(p)); % how many plot rows
cols = ceil(p/rows); % how many plot columns
L = daubcofs(n);

clg;

% levels and shifts
LS = [([-1:1:p-1]'),zeros(p+1,1)];

for i = 1:(rows*cols),
  lev = LS(i,1); % level
  sh = LS(i,2); % shift
  
  if(lev == -1),
    w = [1; zeros(2^p - 1,1)];
    f = idpwt(w,L,0);
  else,
    w = putlevel(zeros(2^p,1), ([0:(2^lev - 1)]==sh), lev);
    f = idpwt(w,L,lev);
  end
  
  % Scale f to lie between -1 and 1
  
  m = max(abs(f));
  ff = f/m;
  subplot(rows,cols,i);
  plotperdisc(ff);
  title(sprintf('level %d',i-2));
  drawnow
end;