binlwavf.m

关于小波分析的 具体是什么 我也不太清楚

function [Rf,Df] = binlwavf(wname)
%BINLWAVF Biorthogonal wavelet filters (binary wavelets: Binlets).
%   [RF,DF] = BINLWAVF(W) 返回两个尺度滤波器，其中
%   RF是重建滤波器
%   DF是分解滤波器
%   双正交小波函数由字符串W指明
%   W = 'binlNr.Nd' 其中Nr和Nd的可取值为：     
%   Nr = 7  Nd = 9
%   M. Misiti, Y. Misiti, G. Oppenheim, J.M. Poggi 12-Mar-96.
%   Last Revision: 17-Apr-1998.
%   Copyright 1995-2000 The MathWorks, Inc.
% $Revision: 1.9 $
% 参数校验
if errargn(mfilename,nargin,[0 1],nargout,[0:2]), error('*'); end
%小波函数的扩展语句
Nr = 7; Nd = 9;
% for possible extension
% more wavelets in 'Binlets' family
%----------------------------------
if nargin==0
    Nr = 7; Nd = 9;
elseif  isempty(wname)
    Nr = 7; Nd = 9;
else
    if isstr(wname)
        lw = length(wname);
        ab = abs(wname);
        ind = find(ab==46 | 47<ab | ab<58);
        li = length(ind);
        err = 0;
        if li==0
            err = 1;
        elseif ind(1)~=ind(li)-li+1
            err = 1;
        end 
        if err==0 , 
            wname = wstr2num(wname(ind));
            if isempty(wname) , err = 1; end
        end
    end     
    if err==0
        Nr = fix(wname); Nd = 10*(wname-Nr);
    else
        Nr = 0; Nd = 0;
    end
end
% 函数扩展语句和出错测试
%-------------------------------------------
if Nr~=7 , Nr = 7; end
if Nd~=9 , Nd = 9; end

if Nr == 7
   if Nd == 9
      Rf = [-1 0 9 16 9 0 -1]/32;
      Df = [ 1 0 -8 16 46 16 -8 0 1]/64;
   end
end