faacos.m

最新的HHT时频分析程序By Huang and Wu

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

% The function FAACOS generates an arccosine frequency and amplitude 
% of previously normalized data(n,k), where n is the length of the
% time series and k is the number of IMF components.
% 
% FAACOS finds the frequency by applying
% the arccosine function to the normalized data and
% checking the points where the slope of arccosine phase changes.
% Nature of the procedure suggests not to use the function
% to process the residue component.
%
% Calling sequence-
% [f,a] = faacos(data, dt)
%
% Input-
%	data	- 2-D matrix of IMF components 
%	dt	    - time increment per point
% Output-
%	f	    - 2-D matrix f(n,k) that specifies frequency
%	a	    - 2-D matrix a(n,k) that specifies amplitude
%
% Used by-
%	FA
 
% Kenneth Arnold (NASA GSFC)	Summer 2003, Initial