hilbert2.m

我认为很不错的语音处理的ｍａｔｌａｂ源代码

function [y]=hilbert2(x)
% % hilbert2: Calculates the hilbert transform for a very long signal
% % 
% % Syntax:
% % 
% % [y]=hilbert2(x);
% % 
% % Returns the complex hilbert transform of x to the complex variable y.
% % Leading singelton dimensions of x are removed.  
% % 
% % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% 
% Example='1';
% 
% x=randn(2, 100000);
% tic; [y]=hilbert2(x')'; t2=toc;
% 
% Example='2';
% tic; [y2]=hilbert(x')'; t3=toc;
% 
% 
% % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% % Program Written by Edward L. Zechmann
% % 
% %     date 22 April     2008
% % 
% % modified 10 September 2008  Added Comments
% %  
% % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% % Please feel free to modify this code.
% % 
% % See Also: hilbert, fft, ifft
% % 
% % 


if ~isreal(x)
  warning('HILBERT ignores imaginary part of input.')
  x = real(x);
end

% Work along the first nonsingleton dimension
[x,nshifts] = shiftdim(x);

length_x=size(x, 1);

% maximum number of elements in a bin
bin_size=2^12;

% Maximum size of array before it is necessary to break up the array into
% bins

flag=0;
if length_x > 4*bin_size    
    flag=1;
end



if flag == 1

    if length_x > bin_size
        num_bins=ceil(length_x/bin_size);
    end

    y=zeros(size(x));

    for e1=1:num_bins;

        if e1 == num_bins
            buf=x( (1+(e1-1)*bin_size):end, :);
        else
            buf=x( (1+(e1-1)*bin_size):(e1*bin_size), :);
        end

        % Reverse the fist half and second half and append to the
        % beginning and end of the array.
        %
        % This will reduce the extraneous peaks that may be added to
        % the signal.
        %
        
        n1=length(buf);
        n2=floor(n1/2);
        buf2=[buf(n2:(-1):1, :)' buf(1:n1, :)'  buf(n1:(-1):(n2+1), :)' ]';
        buf3 = hilbert(buf2);

        if e1 == num_bins
            y((1+(e1-1)*bin_size):end, :)=buf3(n2+(1:n1), :);
        else
            y((1+(e1-1)*bin_size):(e1*bin_size), :)=buf3(n2+(1:n1), :);
        end
        
    end

else
    
    [y]=hilbert(x);
    
end