wavenorm.m

波形数据归一化操作

function wnorm = wavenorm(w,tw,flag)
% WAVENORM: normalize a wavelet
%
% wnorm = wavenorm(w,tw,flag)
%
% WAVENORM normalizes a wavelet by one of several criteria.
% The choices are: (1) normalize the maximum absolut value to unity
% (2) normalize such that a sine wave at the dominant frequency passes
% with unit amplitude (3) normalize the rms amplitude to unity.
%
% w ... input wavelet
% tw ... time coordinate vector for w
% flag ... (1) normalize the maximum absolute value to unity
%          (2) normalize such that a sine wave at the dominant frequency 
%              passes with unit amplitude
%          (3) normalize the rms amplitude to unity
% 
% by G.F. Margrave, May 1991
%
% NOTE: It is illegal for you to use this software for a purpose other
% than non-profit education or research UNLESS you are employed by a CREWES
% Project sponsor. By using this software, you are agreeing to the terms
% detailed in this software's Matlab source file.
 
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%
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% of Geology and Geophysics of the University of Calgary, Calgary,
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if(flag==1)
    wnorm = w/max(abs(w));
elseif(flag==2)
    %compute spectrum
    [W,f]=fftrl(w,tw);
    A=real(todb(W));
    %pick maximum amplitude
    ind=find(A==max(A));
    fdom = f(ind(1));
    refwave=sin(2*pi*fdom*tw);
    reftest=convz(refwave,w);
    fact=max(refwave)/max(reftest);
    wnorm=w*fact;
elseif(flag==3)
    rms_ave=norm(w)/sqrt(length(w));
    wnorm=w/rms_ave;
else
    error('invalid flag')
end