ft_trialfun_brainvision_segmented.m
8a186cd82567master

ft_trialfun_brainvision_segmented.m
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			function [trl, event] = ft_trialfun_brainvision_segmented(cfg)
			% FT_TRIALFUN_BRAINVISION_SEGMENTED creates trials for a Brain Vision Analyzer
			% dataset that was segmented in the BVA software.
			%
			% Use as
			% cfg = [];
			% cfg.dataset = '<datasetname>.vhdr';
			% cfg.trialfun = 'ft_trialfun_brainvision_segmented';
			% cfg = ft_definetrial(cfg);
			% data = ft_preprocessing(cfg);
			%
			% Optionally, you can also specify:
			% cfg.trigformat = 'S %d';
			% which will instruct this function to parse stimulus triggers according to
			% the format you specified. The default is 'S %d'. cfg.trigformat always
			% needs to contain exactly one %d code. Trigger values read in this way
			% will be stored in columns 4 and upwards of the output 'trl' matrix, and
			% will end up in data.trialinfo if this matrix is subsequently passed to
			% ft_preprocessing in order to read in data.
			%
			% A dataset needs to consist of three files: a .eeg, .vhdr, and .vmrk file.
			% cfg.dataset needs to refer to the .vhdr file.
			%
			% See also FT_DEFINETRIAL, FT_PREPROCESSING

			% Copyright (C) 20014, Robert Oostenveld, FCDC
			%
			% This file is part of FieldTrip, see http://www.ru.nl/neuroimaging/fieldtrip
			% for the documentation and details.
			%
			% FieldTrip 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 3 of the License, or
			% (at your option) any later version.
			%
			% FieldTrip 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 FieldTrip. If not, see <http://www.gnu.org/licenses/>.
			%
			% $Id: ft_trialfun_brainvision_segmented.m 9825 2014-09-22 15:19:53Z roboos $

			hdr = ft_read_header(cfg.dataset);
			event = ft_read_event(cfg.dataset);

			% set the defaults
			cfg.trigformat = ft_getopt(cfg, 'trigformat', 'S %d');

			sel = find(strcmp({event.type}, 'New Segment'));
			ntrial = length(sel);
			fprintf('found %d segments in the data\n', ntrial);

			sample = [event.sample];
			if any(diff(sample)<0)
			% events should be ordered according to the sample in the file at which they occur
			warning('reordering events based on their sample number');
			[sample, order] = sort(sample);
			event = event(order);
			end

			% for Brain Vision Analyzer the event type and value are strings
			type = {event.type};
			value = {event.value};

			begsample = nan(1,ntrial);
			endsample = nan(1,ntrial);
			offset = nan(1,ntrial);
			stim = cell(1,ntrial);

			for i=1:ntrial
			begevt = sel(i);
			if i<ntrial
			endevt = sel(i+1);
			else
			endevt = length(event);
			end

			% specify at which data sample the trial begins
			begsample(i) = sample(sel(i));

			% find the sample on which the trial is time-locked
			t0 = find(strcmp(type((begevt+1):endevt), 'Time 0'));
			t0 = t0(1); % take the first one in case there are multiple
			offset(i) = -(sample(begevt+t0) - begsample(i));

			% construct a list of all stimulus events in each segment
			stim{i} = find(strcmp(type((begevt+1):endevt), 'Stimulus'))+begevt;
			end

			% the endsample of each trial aligns with the beginsample of the next one
			endsample(1:end-1) = begsample(2:end);
			% the last endsample corresponds to the end of the file
			endsample(end) = hdr.nSamples*hdr.nTrials;

			% add the stimulus events to the output, if possible
			numstim = cellfun(@length, stim);
			if all(numstim==numstim(1))
			for i=1:length(stim)
			for j=1:numstim(i)
			stimvalue = sscanf(value{stim{i}(j)}, cfg.trigformat);
			stimsample = sample(stim{i}(j));
			stimtime = (stimsample - begsample(i) + offset(i))/hdr.Fs; % relative to 'Time 0'
			trialinfo(i,2*(j-1)+1) = stimvalue;
			trialinfo(i,2*(j-1)+2) = stimtime;
			end % j
			end % i
			else
			warning('the trials have a varying number of stimuli, not adding them to the "trl" matrix');
			trialinfo = [];
			end

			% combine the sample information and the trial information
			trl = cat(2, [begsample(:) endsample(:) offset(:)], trialinfo);

Slepi/Code/Utilities/spm12/external/fieldtrip/trialfun/ft_trialfun_brainvision_segmented.m8a186cd82567master

ft_trialfun_brainvision_segmented.mView Options

Slepi/Code/Utilities/spm12/external/fieldtrip/trialfun/ft_trialfun_brainvision_segmented.m
8a186cd82567master

ft_trialfun_brainvision_segmented.m
View Options