www.pudn.com > multiwavelet.rar > prep1D_rr.m

function fp=prep1D_rr(f,flt) 
%fp=prep1D_rr(f,flt)  
% 
%  This function performs oversampled ("repeated row") preprocessing of given  
%  1-dimensional signal. For description of the algorithm see [SW] 
% 
%  rr 这是重复行预滤波；这个函数与post1D_rr.m共同使用； 
% 
%  Input: 
%    flt        string of characters, name of the filter to be used;  
%               for possible names and short descriptions see coef.m  
%    f          1 by n real array, input signal;//1-D输入信号 
% 
%    n          n must be of the form integer*2^maxlevel,//输入信号的长度 
%    maxlevel   maxlevel is the number of levels of multiwavelet decomposition //多小波分解的层数 
% 
%  Output:  
%    fp         r by n real array, preprocessed signal;  
%               each row corresponds to a scaling function  
% 
%  Example of Usage: 
%    fp=prep1D_rr(f,'ghm')  
 
% Author: Vasily Strela 
% COPYRIGHT 1997,98 by Vasily Strela 
 
[L,H]=coef(flt); 
 
n=length(f); 
[nf,ns]=size(L); 
ns=ns/nf; 
 
H0=zeros(nf); 
for i=1:ns 
  H0=H0+L(:,nf*(i-1)+1:nf*i); 
end 
[V,D]=eig(H0'/(sqrt(2))); 
fl=0; 
for i=1:nf 
  if abs(D(i,i)-1.)<0.000001 
    fl=i; 
  end 
end 
a0=V(:,fl); 
big=0; 
for i=1:nf 
  if abs(a0(i))>abs(big) 
    big=a0(i); 
  end 
end 
for i=1:nf 
  a0(i)=a0(i)/big; 
end 
 
fp=zeros(nf,n); 
for i=1:nf 
  fp(i,:)=a0(i)*f; 
end