nspplote.m

最新的HHT时频分析程序By Huang and Wu

function [nt,tscale,fscale]=nspplote(f,a,t0,t1,fres,tres,fw0,fw1,tw0,tw1)

% The function NSPPLOTE generates and plots the HHT spectrum of data (or log data) 
% in time-frequency (or time-log frequency) space based on given frequency 
% f(n,k) and amplitude a(n,k), where n specifies the length of time series, and 
% k is the number of IMF components.
%
% NSPPLOTE compute the Hilbert-Huang Spectrum of energy.
%
% Calling sequence-
% [nt,tscale,fscale]= nspplote(f,a[,t0][,t1][,fres][,tres][,fw0][,fw1][,tw0][,tw1][,lscale])
%
% Example, [nt,tscale,fscale]=nspplote(f,a,1,1000,500,300,0,1,1,1000).
%
% Input-
%	  f	          - 2-D matrix that specifies the frequency values
%	  a	          - 2-D matrix that specifies the amplitude values
%	  t0          - true start time
%	  t1          - true end time
%	  fres        - frequency resolution
%	  tres        - time resolution
%	  fw0         - minimum frequency
%	  fw1         - maximum frequency
%	  tw0         - minimum time for zooming
%	  tw1         - maximum time for zooming, if no zooming, tw0=t0, tw1=t1
%        
% Output-
%	  nt          - 2-D matrix that specifies the spectrum
%	  tscale      - vector that specifies the time axis values
%	  fscale      - vector that specifies the frequency axis values
%
% All arguments are required, WITHOUT default values.
%
% Kenneth Arnold (NASA GSFC)		Summer, 2003 Initial
% Jelena Marshak (NASA GSFC)		July 30, 2004 Modified
%                                   	(added the LOG scale option)
% Xianyao Chen     September, 2008
%   nspplote is update version of nspplot. 
%   It is called by nnspe to compute the Hilbert-Huang spectrum of energy.
%   The default input of each arguments are removed for better control of the program