faht.m

最新的HHT时频分析程序By Huang and Wu

function [f, a] = faht(data,dt)

% The function FAHT calculates an improved Hilbert frequency and amplitude
% of data(n,k), where n specifies the length of time series, and 
% k is the number of IMF components.
% 
% hilbtm.m is used to perform a Hilbert transform.
%
% Note: FAH allows the instantaneous frequency to be negative. 
%
% Calling sequence-
% [f,a] = faht(data,dt)
%
% Input-
%   data	- 2-D matrix data(n,k) of IMF components 
%	dt	    - sampling period in seconds
% Output-
%	f	    - 2-D matrix f(n,k) that specifies the Hilbert frequency in Hz
%	a	    - 2-D matrix a(n,k) that specifies the Hilbert amplitude
%
% Used by-
% 	FA, NSPABMUN.
%
% Xianyao Chen, september, 2008
%    hilbt.m is used to perform Hilbert transform instead of hilbert.m,
%     which mainly reduce the Gipps impacts from the end points.