biosig2eeglab.m

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% biosig2eeglab() - convert BIOSIG structue to EEGLAB structure
%
% Usage:
%   >> OUTEEG = pop_biosig2eeglab(hdr, data, interval);
%
% Inputs:
%   hdr   - BIOSIG header
%   data  - BIOSIG data array
%
% Optional input:
%   interval - BIOSIG does not remove event which are outside of
%              the data range when importing data range subsets. This 
%              parameter helps fix this problem.
%
% Outputs:
%   OUTEEG   - EEGLAB data structure
%
% Author: Arnaud Delorme, SCCN, INC, UCSD, Oct. 29, 2009-
%
% Note: BIOSIG toolbox must be installed. Download BIOSIG at 
%       http://biosig.sourceforge.net
%       Contact a.schloegl@ieee.org for troubleshooting using BIOSIG.
 
% Copyright (C) 2003 Arnaud Delorme, SCCN, INC, UCSD, arno@salk.edu
%
% This program is free software; you can redistribute it and/or modify
% it under the terms of the GNU General Public License as published by
% the Free Software Foundation; either version 2 of the License, or
% (at your option) any later version.
%
% This program is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
% GNU General Public License for more details.
%
% You should have received a copy of the GNU General Public License
% along with this program; if not, write to the Free Software
% Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 
function EEG = biosig2eeglab(dat, DAT, interval, channels, importevent);
 
if nargin < 2
    help biosig2eeglab;
    return;
end;
if nargin < 3
    interval = [];
end;
if nargin < 4
    channels = [];
end;
if nargin < 5
    importevent = 0;
end;
 
% import data
% -----------
DAT = DAT';
EEG = eeg_emptyset;
 
% convert to seconds for sread
% ----------------------------
EEG.nbchan          = size(DAT,1);
EEG.srate           = dat.SampleRate(1);
EEG.data            = DAT; 
clear DAT;
% try  % why would you do the following???????  JO
%     EEG.data            = EEG.data';
% catch,
%     pack;
%     EEG.data            = EEG.data';
% end;    
EEG.setname         = sprintf('%s file', dat.TYPE);
EEG.comments        = [ 'Original file: ' dat.FileName ];
EEG.xmin            = 0;
nepoch              = dat.NRec;
EEG.trials   = nepoch;
EEG.pnts     = size(EEG.data,2)/nepoch;
 
if isfield(dat, 'Label') & ~isempty(dat.Label)
    if isstr(dat.Label)
        EEG.chanlocs = struct('labels', cellstr(char(dat.Label)));
    else
        EEG.chanlocs = struct('labels', dat.Label(1:min(length(dat.Label), size(EEG.data,1))));
    end;
    if ~isempty(channels)
        EEG.chanlocs = EEG.chanlocs(channels);
    end;
end
EEG = eeg_checkset(EEG);
 
% extract events % this part I totally revamped to work...  JO
% --------------
EEG.event = [];
 
% startval = mode(EEG.data(end,:)); % my code
% for p = 2:size(EEG.data,2)-1
%     [codeout] = code(EEG.data(end,p));
%     if EEG.data(end,p) > EEG.data(end,p-1) & EEG.data(end,p) >= EEG.data(end,p+1)
%         EEG.event(end+1).latency =  p;
%         EEG.event(end).type = bitand(double(EEG.data(end,p)-startval),255);
%     end;
% end;
 
% lastout = mod(EEG.data(end,1),256);newevs = []; % andrey's code 8 bits
% codeout = mod(EEG.data(end,2),256);
% for p = 2:size(EEG.data,2)-1
%     nextcode = mod(EEG.data(end,p+1),256);
%     if codeout > lastout & codeout >= nextcode
%         newevs = [newevs codeout];
%         EEG.event(end+1).latency =  p;
%         EEG.event(end).type = codeout;
%     end;
%     lastout = codeout;
%     codeout = nextcode;
% end;
 
%lastout = mod(EEG.data(end,1),256*256);newevs = []; % andrey's code 16 bits
%codeout = mod(EEG.data(end,2),256*256);
%for p = 2:size(EEG.data,2)-1
%    nextcode = mod(EEG.data(end,p+1),256*256);
%    if (codeout > lastout) & (codeout >= nextcode)
%        newevs = [newevs codeout];
%        EEG.event(end+1).latency =  p;
%        EEG.event(end).type = codeout;
%    end;
%    lastout = codeout;
%    codeout = nextcode;
%end;
 
if importevent
    if isfield(dat, 'BDF')
        if dat.BDF.Status.Channel <= size(EEG.data,1)
            EEG.data(dat.BDF.Status.Channel,:) = [];
        end;
        EEG.nbchan = size(EEG.data,1);
        if ~isempty(EEG.chanlocs) && dat.BDF.Status.Channel <= length(EEG.chanlocs)
            EEG.chanlocs(dat.BDF.Status.Channel,:) = [];
        end;
    elseif isempty(dat.EVENT.POS)
        disp('Extracting events from last EEG channel...');
        %Modifieded by Andrey (Aug.5,2008) to detect all non-zero codes: 
        if length(unique(EEG.data(end, 1:100))) > 20
            disp('Warning: event extraction failure, the last channel contains data');
        elseif length(unique(EEG.data(end, :))) > 5000
            disp('Warning: event extraction failure, the last channel contains data');
        else
            thiscode = 0;
            for p = 1:size(EEG.data,2)*size(EEG.data,3)-1
                prevcode = thiscode;
                thiscode = mod(EEG.data(end,p),256*256);   % andrey's code - 16 bits 
                if (thiscode ~= 0) && (thiscode~=prevcode) 
                    EEG.event(end+1).latency =  p;
                    EEG.event(end).type = thiscode;
                end;
            end;
            EEG.data(end,:) = [];
            EEG.chanlocs(end) = [];
        end;
        % recreate the epoch field if necessary
        % -------------------------------------
        if EEG.trials > 1
            for i = 1:length(EEG.event)
                EEG.event(i).epoch = ceil(EEG.event(i).latency/EEG.pnts);
            end;
        end;
        EEG = eeg_checkset(EEG, 'eventconsistency');
    end;
 
    if ~isempty(dat.EVENT.POS)    
        if isfield(dat, 'out') % Alois fix for event interval does not work
            if isfield(dat.out, 'EVENT')
                dat.EVENT = dat.out.EVENT;
            end;
        end;
        EEG.event = biosig2eeglabevent(dat.EVENT, interval); % Toby's fix
 
        % recreate the epoch field if necessary
        % -------------------------------------
        if EEG.trials > 1
            for i = 1:length(EEG.event)
                EEG.event(i).epoch = ceil(EEG.event(i).latency/EEG.pnts);
            end;
        end;
 
        EEG = eeg_checkset(EEG, 'eventconsistency');
    elseif isempty(EEG.event) 
        disp('Warning: no event found. Events might be embeded in a data channel.');
        disp('         To extract events, use menu File > Import Event Info > From data channel');
    end;
end;
 
% convert data to single if necessary
% -----------------------------------
EEG = eeg_checkset(EEG,'makeur');   % Make EEG.urevent field
EEG = eeg_checkset(EEG);