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annotate m-toolbox/classes/@ao/computeperiodogram.m @ 26:ce4df2e95a55 database-connection-manager

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Remove LTPDARepositoryManager initialization
author Daniele Nicolodi <nicolodi@science.unitn.it>
date Mon, 05 Dec 2011 16:20:06 +0100
parents f0afece42f48
children
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Daniele Nicolodi <nicolodi@science.unitn.it>
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1 % COMPUTEPERIODOGRAM Periodogram spectral estimation.
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Daniele Nicolodi <nicolodi@science.unitn.it>
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2 % This function is used to calculate the Power Spectrum Sxx, and the
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Daniele Nicolodi <nicolodi@science.unitn.it>
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3 % Cross Power Spectrum Sxy.
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Daniele Nicolodi <nicolodi@science.unitn.it>
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4 %
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Daniele Nicolodi <nicolodi@science.unitn.it>
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5 % Sxx = COMPUTEPERIODOGRAM(X,WIN,NFFT) where x is a vector returns the
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Daniele Nicolodi <nicolodi@science.unitn.it>
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6 % Power Spectrum over the whole Nyquist interval, [0, 2pi).
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Daniele Nicolodi <nicolodi@science.unitn.it>
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7 %
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Daniele Nicolodi <nicolodi@science.unitn.it>
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8 % Sxy = COMPUTEPERIODOGRAM({X,Y},WIN,NFFT) returns the Cross Power
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Daniele Nicolodi <nicolodi@science.unitn.it>
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9 % Spectrum over the whole Nyquist interval, [0, 2pi).
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Daniele Nicolodi <nicolodi@science.unitn.it>
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10 %
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Daniele Nicolodi <nicolodi@science.unitn.it>
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11 % Inputs:
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Daniele Nicolodi <nicolodi@science.unitn.it>
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12 % X - Signal vector or a cell array of two elements containing
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Daniele Nicolodi <nicolodi@science.unitn.it>
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13 % two signal vectors.
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Daniele Nicolodi <nicolodi@science.unitn.it>
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14 % WIN - Window
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Daniele Nicolodi <nicolodi@science.unitn.it>
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15 % NFFT - Number of frequency points (FFT) or vector of
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Daniele Nicolodi <nicolodi@science.unitn.it>
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16 % frequencies at whicch periodogram is desired (Goertzel)
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Daniele Nicolodi <nicolodi@science.unitn.it>
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17 % WINCOMPFLAG - A string indicating the type of window compensation to
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Daniele Nicolodi <nicolodi@science.unitn.it>
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18 % be done. The choices are:
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Daniele Nicolodi <nicolodi@science.unitn.it>
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19 % 'ms' - compensate for Mean-square (Power) Spectrum;
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Daniele Nicolodi <nicolodi@science.unitn.it>
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20 % maintain the correct power peak heights.
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Daniele Nicolodi <nicolodi@science.unitn.it>
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21 % 'psd' - compensate for Power Spectral Denstiy (PSD);
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Daniele Nicolodi <nicolodi@science.unitn.it>
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22 % maintain correct area under the PSD curve.
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Daniele Nicolodi <nicolodi@science.unitn.it>
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23 %
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Daniele Nicolodi <nicolodi@science.unitn.it>
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24 % Output:
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Daniele Nicolodi <nicolodi@science.unitn.it>
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25 % Sxx - Power spectrum [Power] over the whole Nyquist interval.
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Daniele Nicolodi <nicolodi@science.unitn.it>
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26 % or
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Daniele Nicolodi <nicolodi@science.unitn.it>
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27 % Sxy - Cross power spectrum [Power] over the whole Nyquist
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Daniele Nicolodi <nicolodi@science.unitn.it>
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28 % interval.
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Daniele Nicolodi <nicolodi@science.unitn.it>
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29 %
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Daniele Nicolodi <nicolodi@science.unitn.it>
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30 % A direct copy of MATLAB's function for LTPDA
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Daniele Nicolodi <nicolodi@science.unitn.it>
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31 %
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Daniele Nicolodi <nicolodi@science.unitn.it>
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32 % M Hewitson 08-05-08
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Daniele Nicolodi <nicolodi@science.unitn.it>
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33 %
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Daniele Nicolodi <nicolodi@science.unitn.it>
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34 % $Id: computeperiodogram.m,v 1.2 2008/08/01 13:19:42 ingo Exp $
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Daniele Nicolodi <nicolodi@science.unitn.it>
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35 %
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Daniele Nicolodi <nicolodi@science.unitn.it>
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36
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Daniele Nicolodi <nicolodi@science.unitn.it>
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37 % Author(s): P. Pacheco
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Daniele Nicolodi <nicolodi@science.unitn.it>
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38 % Copyright 1988-2006 The MathWorks, Inc.
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Daniele Nicolodi <nicolodi@science.unitn.it>
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39 % $Revision: 1.2 $ $Date: 2008/08/01 13:19:42 $
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Daniele Nicolodi <nicolodi@science.unitn.it>
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40
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Daniele Nicolodi <nicolodi@science.unitn.it>
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41 function [P,f] = computeperiodogram(x,win,nfft,esttype,varargin)
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Daniele Nicolodi <nicolodi@science.unitn.it>
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42
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Daniele Nicolodi <nicolodi@science.unitn.it>
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43 error(nargchk(3,5,nargin,'struct'));
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Daniele Nicolodi <nicolodi@science.unitn.it>
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44 if nargin < 4,
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Daniele Nicolodi <nicolodi@science.unitn.it>
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45 esttype = 'psd'; % Default, compenstate for window's power.
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Daniele Nicolodi <nicolodi@science.unitn.it>
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46 end
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Daniele Nicolodi <nicolodi@science.unitn.it>
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47
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Daniele Nicolodi <nicolodi@science.unitn.it>
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48 if nargin < 5 || isempty(varargin{1}),
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Daniele Nicolodi <nicolodi@science.unitn.it>
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49 Fs = 2*pi;
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Daniele Nicolodi <nicolodi@science.unitn.it>
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50 else
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Daniele Nicolodi <nicolodi@science.unitn.it>
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51 Fs = varargin{1};
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Daniele Nicolodi <nicolodi@science.unitn.it>
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52 end
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Daniele Nicolodi <nicolodi@science.unitn.it>
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53
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Daniele Nicolodi <nicolodi@science.unitn.it>
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54 % Validate inputs and convert row vectors to column vectors.
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Daniele Nicolodi <nicolodi@science.unitn.it>
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55 [x,Lx,y,is2sig,win,errid,errmsg] = validateinputs(x,win,nfft);
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Daniele Nicolodi <nicolodi@science.unitn.it>
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56 if ~isempty(errmsg), error(errid, errmsg); end
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Daniele Nicolodi <nicolodi@science.unitn.it>
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57
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Daniele Nicolodi <nicolodi@science.unitn.it>
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58 % Determine if FFT or Goertzel
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Daniele Nicolodi <nicolodi@science.unitn.it>
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59 freqVectorSpecified = false;
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Daniele Nicolodi <nicolodi@science.unitn.it>
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60 if (length(nfft)> 1), freqVectorSpecified = true; end
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Daniele Nicolodi <nicolodi@science.unitn.it>
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61
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Daniele Nicolodi <nicolodi@science.unitn.it>
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62 % Window the data
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Daniele Nicolodi <nicolodi@science.unitn.it>
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63 xw = x.*win;
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Daniele Nicolodi <nicolodi@science.unitn.it>
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64 if is2sig, yw = y.*win; end
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Daniele Nicolodi <nicolodi@science.unitn.it>
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65
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Daniele Nicolodi <nicolodi@science.unitn.it>
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66 % Evaluate the window normalization constant. A 1/N factor has been
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Daniele Nicolodi <nicolodi@science.unitn.it>
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67 % omitted since it will cancel below.
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Daniele Nicolodi <nicolodi@science.unitn.it>
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68 if strcmpi(esttype,'ms'),
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Daniele Nicolodi <nicolodi@science.unitn.it>
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69 % The window is convolved with every power spectrum peak, therefore
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Daniele Nicolodi <nicolodi@science.unitn.it>
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70 % compensate for the DC value squared to obtain correct peak heights.
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Daniele Nicolodi <nicolodi@science.unitn.it>
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71 U = sum(win)^2;
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Daniele Nicolodi <nicolodi@science.unitn.it>
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72 else
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Daniele Nicolodi <nicolodi@science.unitn.it>
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73 U = win'*win; % compensates for the power of the window.
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Daniele Nicolodi <nicolodi@science.unitn.it>
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74 end
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Daniele Nicolodi <nicolodi@science.unitn.it>
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75
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Daniele Nicolodi <nicolodi@science.unitn.it>
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76 % Compute the periodogram power spectrum [Power] estimate
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Daniele Nicolodi <nicolodi@science.unitn.it>
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77 % A 1/N factor has been omitted since it cancels
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Daniele Nicolodi <nicolodi@science.unitn.it>
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78
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Daniele Nicolodi <nicolodi@science.unitn.it>
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79 [Xx,f] = ao.computeDFT(xw,nfft,Fs);
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Daniele Nicolodi <nicolodi@science.unitn.it>
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80 if is2sig, [Yy,f] = ao.computeDFT(yw,nfft,Fs); end
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Daniele Nicolodi <nicolodi@science.unitn.it>
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81
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Daniele Nicolodi <nicolodi@science.unitn.it>
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82 P = Xx.*conj(Xx)/U; % Auto spectrum.
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Daniele Nicolodi <nicolodi@science.unitn.it>
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83 if is2sig,
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Daniele Nicolodi <nicolodi@science.unitn.it>
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84 P = Xx.*conj(Yy)/U; % Cross spectrum.
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Daniele Nicolodi <nicolodi@science.unitn.it>
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85 end
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Daniele Nicolodi <nicolodi@science.unitn.it>
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86
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Daniele Nicolodi <nicolodi@science.unitn.it>
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87 end
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Daniele Nicolodi <nicolodi@science.unitn.it>
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88
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Daniele Nicolodi <nicolodi@science.unitn.it>
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89 %--------------------------------------------------------------------------
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Daniele Nicolodi <nicolodi@science.unitn.it>
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90 function [x,Lx,y,is2sig,win,errid,errmsg] = validateinputs(x,win,nfft)
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Daniele Nicolodi <nicolodi@science.unitn.it>
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91 % Validate the inputs to computexperiodogram and convert the input signal
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Daniele Nicolodi <nicolodi@science.unitn.it>
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92 % vectors into column vectors.
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Daniele Nicolodi <nicolodi@science.unitn.it>
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93
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Daniele Nicolodi <nicolodi@science.unitn.it>
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94 errid = '';
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Daniele Nicolodi <nicolodi@science.unitn.it>
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95 errmsg = ''; % in case of early return.
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Daniele Nicolodi <nicolodi@science.unitn.it>
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96
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Daniele Nicolodi <nicolodi@science.unitn.it>
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97 % Set defaults and convert to row vectors to columns.
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Daniele Nicolodi <nicolodi@science.unitn.it>
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98 y = [];
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Daniele Nicolodi <nicolodi@science.unitn.it>
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99 Ly = 0;
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Daniele Nicolodi <nicolodi@science.unitn.it>
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100 is2sig= false;
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Daniele Nicolodi <nicolodi@science.unitn.it>
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101 win = win(:);
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Daniele Nicolodi <nicolodi@science.unitn.it>
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102 Lw = length(win);
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Daniele Nicolodi <nicolodi@science.unitn.it>
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103
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Daniele Nicolodi <nicolodi@science.unitn.it>
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104 % Determine if one or two signal vectors was specified.
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Daniele Nicolodi <nicolodi@science.unitn.it>
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105 Lx = length(x);
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Daniele Nicolodi <nicolodi@science.unitn.it>
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106 if iscell(x),
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Daniele Nicolodi <nicolodi@science.unitn.it>
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107 if length(x) > 1,
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Daniele Nicolodi <nicolodi@science.unitn.it>
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108 y = x{2};
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Daniele Nicolodi <nicolodi@science.unitn.it>
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109 y = y(:);
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Daniele Nicolodi <nicolodi@science.unitn.it>
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110 is2sig = true;
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Daniele Nicolodi <nicolodi@science.unitn.it>
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111 end
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Daniele Nicolodi <nicolodi@science.unitn.it>
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112 x = x{1};
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Daniele Nicolodi <nicolodi@science.unitn.it>
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113 Lx = length(x);
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Daniele Nicolodi <nicolodi@science.unitn.it>
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114 end
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Daniele Nicolodi <nicolodi@science.unitn.it>
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115 x = x(:);
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Daniele Nicolodi <nicolodi@science.unitn.it>
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116
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Daniele Nicolodi <nicolodi@science.unitn.it>
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117 if is2sig,
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Daniele Nicolodi <nicolodi@science.unitn.it>
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118 Ly = length(y);
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Daniele Nicolodi <nicolodi@science.unitn.it>
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119 if Lx ~= Ly,
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Daniele Nicolodi <nicolodi@science.unitn.it>
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120 errid = generatemsgid('invalidInputSignalLength');
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Daniele Nicolodi <nicolodi@science.unitn.it>
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121 errmsg = 'The length of the two input vectors must be equal to calculate the cross spectral density.';
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Daniele Nicolodi <nicolodi@science.unitn.it>
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122 return;
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Daniele Nicolodi <nicolodi@science.unitn.it>
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123 end
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Daniele Nicolodi <nicolodi@science.unitn.it>
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124 end
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Daniele Nicolodi <nicolodi@science.unitn.it>
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125
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Daniele Nicolodi <nicolodi@science.unitn.it>
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126 if Lx ~= Lw,
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Daniele Nicolodi <nicolodi@science.unitn.it>
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127 errid = generatemsgid('invalidWindow');
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Daniele Nicolodi <nicolodi@science.unitn.it>
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128 errmsg = 'The WINDOW must be a vector of the same length as the signal.';
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Daniele Nicolodi <nicolodi@science.unitn.it>
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129 return;
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Daniele Nicolodi <nicolodi@science.unitn.it>
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130 end
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Daniele Nicolodi <nicolodi@science.unitn.it>
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131
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Daniele Nicolodi <nicolodi@science.unitn.it>
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132 end
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Daniele Nicolodi <nicolodi@science.unitn.it>
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133
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Daniele Nicolodi <nicolodi@science.unitn.it>
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134