coherencysegpb.m 5.2 KB

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  1. function [C,phi,S12,S1,S2,f,zerosp,confC,phistd,Cerr]=coherencysegpb(data1,data2,win,params,segave,fscorr)
  2. % Multi-taper coherency,cross-spectrum and individual spectra computed by segmenting
  3. % two univariate binned point processes into chunks
  4. %
  5. % Usage:
  6. % [C,phi,S12,S1,S2,f,zerosp,confC,phistd,Cerr]=coherencysegpb(data1,data2,win,params,segave,fscorr)
  7. % Input:
  8. % Note units have to be consistent. See chronux.m for more information.
  9. % data1 (column vector, binned point process data) -- required
  10. % data2 (column vector, binned point process data) -- required
  11. % win (length of segments) - required
  12. % params: structure with fields tapers, pad, Fs, fpass, err
  13. % - optional
  14. % tapers : precalculated tapers from dpss or in the one of the following
  15. % forms:
  16. % (1) A numeric vector [TW K] where TW is the
  17. % time-bandwidth product and K is the number of
  18. % tapers to be used (less than or equal to
  19. % 2TW-1).
  20. % (2) A numeric vector [W T p] where W is the
  21. % bandwidth, T is the duration of the data and p
  22. % is an integer such that 2TW-p tapers are used. In
  23. % this form there is no default i.e. to specify
  24. % the bandwidth, you have to specify T and p as
  25. % well. Note that the units of W and T have to be
  26. % consistent: if W is in Hz, T must be in seconds
  27. % and vice versa. Note that these units must also
  28. % be consistent with the units of params.Fs: W can
  29. % be in Hz if and only if params.Fs is in Hz.
  30. % The default is to use form 1 with TW=3 and K=5
  31. %
  32. % pad (padding factor for the FFT) - optional (can take values -1,0,1,2...).
  33. % -1 corresponds to no padding, 0 corresponds to padding
  34. % to the next highest power of 2 etc.
  35. % e.g. For N = 500, if PAD = -1, we do not pad; if PAD = 0, we pad the FFT
  36. % to 512 points, if pad=1, we pad to 1024 points etc.
  37. % Defaults to 0.
  38. % Fs (sampling frequency) - optional. Default 1.
  39. % fpass (frequency band to be used in the calculation in the form
  40. % [fmin fmax])- optional.
  41. % Default all frequencies between 0 and Fs/2
  42. % err (error calculation [1 p] - Theoretical error bars; [2 p] - Jackknife error bars
  43. % [0 p] or 0 - no error bars) - optional. Default 0.
  44. % segave (average over segments for 1, don't average for 0)
  45. % fscorr (finite size corrections, 0 (don't use finite size corrections) or
  46. % 1 (use finite size corrections) - optional
  47. % (available only for spikes). Defaults 0.
  48. % Output:
  49. % C (magnitude of coherency - frequencies x segments if segave=0; dimension frequencies if segave=1)
  50. % phi (phase of coherency - frequencies x segments if segave=0; dimension frequencies if segave=1)
  51. % S12 (cross spectrum - frequencies x segments if segave=0; dimension frequencies if segave=1)
  52. % S1 (spectrum 1 - frequencies x segments if segave=0; dimension frequencies if segave=1)
  53. % S2 (spectrum 2 - frequencies x segments if segave=0; dimension
  54. % frequencies if segave=1)
  55. % f (frequencies)
  56. % zerosp (1 for segments where no spikes were found, 0 otherwise)
  57. % confC (confidence level for C at 1-p %)
  58. % phistd - jackknife/theoretical standard deviation for phi - Note that
  59. % phi + 2 phistd and phi -2 phistd will give 95% confidence bands for phi -
  60. % only for err(1)>=1
  61. % Cerr (Jackknife error bars for C - use only for Jackknife)
  62. if nargin < 3; error('Need data1 and data2 and size of segment'); end;
  63. if nargin < 4; params=[]; end;
  64. [tapers,pad,Fs,fpass,err,trialave,params]=getparams(params);
  65. clear tapers pad fpass trialave
  66. if nargin < 5 || isempty(segave); segave=1;end;
  67. if nargin < 6 || isempty(fscorr); fscorr=0; end;
  68. if nargout > 9 && err(1)~=2;
  69. error('Cerr computed only for Jackknife. Correct inputs and run again');
  70. end;
  71. if nargout > 7 && err(1)==0;
  72. error('When error are desired, err(1) has to be non-zero.');
  73. end;
  74. N=check_consistency(data1,data2);
  75. dt=1/Fs; % sampling interval
  76. T=N*dt; % length of data in seconds
  77. E=0:win:T-win; % fictitious event triggers
  78. win=[0 win]; % use window length to define left and right limits of windows around triggers
  79. data1=createdatamatpb(data1,E,Fs,win); % segmented data 1
  80. data2=createdatamatpb(data2,E,Fs,win); % segmented data 2
  81. params.trialave=segave;
  82. if err(1)==0;
  83. [C,phi,S12,S1,S2,f,zerosp]=coherencypb(data1,data2,params,fscorr); % compute coherency for segmented data
  84. elseif err(1)==1;
  85. [C,phi,S12,S1,S2,f,zerosp,confC,phistd]=coherencypb(data1,data2,params,fscorr); % compute coherency for segmented data
  86. elseif err(1)==2;
  87. [C,phi,S12,S1,S2,f,zerosp,confC,phistd,Cerr]=coherencypb(data1,data2,params,fscorr); % compute coherency for segmented data
  88. end;