eeg_eventhist.m

含有多种ICA算法的eeglab工具箱

%
% eeg_eventhist() - return or plot histogram of event or urevent field values. 
%                   If NO output args, plots the histogram. If the field values 
%                   are not numbers or strings, no histogram is computed.
% Usage:
%         >> [vals] = eeg_eventhist(Event,'field');   % returns the field values 
%         >> figure; eeg_eventhist(Event,'field',bins);    % plots the histogram
%         >> [vals,histNs,bins] = eeg_eventhist(Event,'field',bins);   % no plot
%
% Inputs:
%
%  Event  - an EEGLAB EEG.event or EEG.urevent structure 
% 'field' - string containing the name of a field in the Event structure
%  bins   - optional number of bins to use, else vector of bin edges {default: 10}
%           If event field values are strings, this argument is not used.
%
% Outputs:
%
% vals    - numeric, struct, or cell array vector of field values for each event
%             in the input event order
% histNs  - numbers of events in the histogram bins
% outbins - if numeric values, a one-column matrix giving bin edges of the [low,high) bins. 
%           Else, if string values, cell array containing the string associated with each bin.
%
% Example:
%             >> [vals,histNs,bins] = eeg_eventhist(EEG.event,'type');
%             %
%             % Returns cell array of event-type strings, numbers of each event type, 
%             % and event type strings, in alphabetic order. No plot produced.
%
% See also:  pop_eventstat(), signalstat(), pop_signalstat().
%
% Author: Scott Makeig, SCCN, Institute for Neural Computation, UCSD, March 26, 2004
%

function [vals,histNs,outbins] = eeg_eventhist(Event,field,bins)

if nargin < 2
  help eeg_eventhist
  return
end

if nargin < 3
  bins = 10;
end

if isempty(Event)
  error('Event structure is empty');
end
if ~isfield(Event,field)
  error('named field is not an Event field')
end

field1 = getfield(Event(1),field);
if ischar(field1)
      IS_CHAR = 1;
elseif isstruct(field1)
      IS_STRUCT = 1;
else
      IS_NUM = 1;
end

if exist('IS_NUM')
  vals = zeros(length(Event),1);
elseif exist('IS_CHAR')
  vals = cell(length(Event),1);
elseif exist('IS_STRUCT')
  vals = repmat(field1,length(Event),1);
else
  error('unknown field type')
end

if exist('IS_NUM')
  for k=1:length(Event)
     vals(k) = getfield(Event(k),field);
  end
else
  for k=1:length(Event)
     vals{k} = getfield(Event(k),field);
  end
end
if nargout == 1 | exist('IS_STRUCT')
  return      % return vals only, no histogram 
end
%
if exist('IS_NUM')  %%%%%%%%%%%%%%%% numeric values histogram %%%%%%%%%%%%%%%%%%%%%%
%   
  if numel(bins) == 1
    if bins < 3
       error('number of bins must be > 2');
    end

    mn = mean(vals);
    stdev = std(vals);

    binsout = zeros(bins,1);
    fl2 = floor(bins/2);
    for k = -1*fl2:ceil(bins/2)
       binsout(k+fl2+1) = mn+k*stdev;
    end
    binsout(1) = -inf;
    binsout(end) = inf;

    histNs = histc(vals,binsout);
    histNs = histNs(1:end-1);

  else  % accomodate specified bin edges
   histNs = histc(vals,bins);
   histNs = histNs(1:end-1);
  end

  outbins = binsout;
  if nargout == 0
    h = bar(histNs,'histc');
  end
%
else  % exist('IS_CHAR')   %%%%%%%%%%%% string values histogram %%%%%%%%%%%%%%%%%%%%%%
%
   outbins = unique(vals);
   histNs = zeros(length(outbins)-1,1);
   for k=1:length(outbins)
     histNs(k) = sum(ismember(vals,outbins{k}));
   end

   if nargout == 0
      h = bar(histNs,1);
      % set(h,'xticklabel',outbins); % ??? NEEDS MORE WORK - CANT TEST FROM HOME
   end
end

return