function [nt,tscale,fscale]=nspplota(f,a,t0,t1,fres,tres,fw0,fw1,tw0,tw1)% The function NSPPLOTA generates and plots the HHT spectrum of 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.%% NSPPLOTA compute the Hilbert-Huang Spectrum of amplitude.%% Calling sequence-% [nt,tscale,fscale]= nspplota(f,a[,t0][,t1][,fres][,tres][,fw0][,fw1][,tw0][,tw1][,lscale])%% Example, [nt,tscale,fscale]=nspplota(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%   nspplota 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