Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
branch: master
124 lines (102 sloc) 4.262 kb
% firfilt() - Pad data with DC constant, filter data with FIR filter,
% and shift data by the filter's group delay
%
% Usage:
% >> EEG = firfilt(EEG, b, nFrames);
%
% Inputs:
% EEG - EEGLAB EEG structure
% b - vector of filter coefficients
%
% Optional inputs:
% nFrames - number of frames to filter per block {default 1000}
%
% Outputs:
% EEG - EEGLAB EEG structure
%
% Note:
% Higher values for nFrames increase speed and working memory
% requirements.
%
% Author: Andreas Widmann, University of Leipzig, 2005
%
% See also:
% filter, findboundaries
%123456789012345678901234567890123456789012345678901234567890123456789012
% Copyright (C) 2005 Andreas Widmann, University of Leipzig, widmann@uni-leipzig.de
%
% 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 = firfilt(EEG, b, nFrames)
if nargin < 2
error('Not enough input arguments.');
end
if nargin < 3 || isempty(nFrames)
nFrames = 1000;
end
% Filter's group delay
if mod(length(b), 2) ~= 1
error('Filter order is not even.');
end
groupDelay = (length(b) - 1) / 2;
% Find data discontinuities and reshape epoched data
if EEG.trials > 1 % Epoched data
EEG.data = reshape(EEG.data, [EEG.nbchan EEG.pnts * EEG.trials]);
dcArray = 1 : EEG.pnts : EEG.pnts * (EEG.trials + 1);
else % Continuous data
dcArray = [findboundaries(EEG.event) EEG.pnts + 1];
end
% Initialize progress indicator
nSteps = 20;
step = 0;
fprintf(1, 'firfilt(): |');
strLength = fprintf(1, [repmat(' ', 1, nSteps - step) '| 0%%']);
tic
for iDc = 1:(length(dcArray) - 1)
% Pad beginning of data with DC constant and get initial conditions
ziDataDur = min(groupDelay, dcArray(iDc + 1) - dcArray(iDc));
[temp, zi] = filter(b, 1, double([EEG.data(:, ones(1, groupDelay) * dcArray(iDc)) ...
EEG.data(:, dcArray(iDc):(dcArray(iDc) + ziDataDur - 1))]), [], 2);
blockArray = [(dcArray(iDc) + groupDelay):nFrames:(dcArray(iDc + 1) - 1) dcArray(iDc + 1)];
for iBlock = 1:(length(blockArray) - 1)
% Filter the data
[EEG.data(:, (blockArray(iBlock) - groupDelay):(blockArray(iBlock + 1) - groupDelay - 1)), zi] = ...
filter(b, 1, double(EEG.data(:, blockArray(iBlock):(blockArray(iBlock + 1) - 1))), zi, 2);
% Update progress indicator
[step, strLength] = mywaitbar((blockArray(iBlock + 1) - groupDelay - 1), size(EEG.data, 2), step, nSteps, strLength);
end
% Pad end of data with DC constant
temp = filter(b, 1, double(EEG.data(:, ones(1, groupDelay) * (dcArray(iDc + 1) - 1))), zi, 2);
EEG.data(:, (dcArray(iDc + 1) - ziDataDur):(dcArray(iDc + 1) - 1)) = ...
temp(:, (end - ziDataDur + 1):end);
% Update progress indicator
[step, strLength] = mywaitbar((dcArray(iDc + 1) - 1), size(EEG.data, 2), step, nSteps, strLength);
end
% Reshape epoched data
if EEG.trials > 1
EEG.data = reshape(EEG.data, [EEG.nbchan EEG.pnts EEG.trials]);
end
% Deinitialize progress indicator
fprintf(1, '\n')
end
function [step, strLength] = mywaitbar(compl, total, step, nSteps, strLength)
progStrArray = '/-\|';
tmp = floor(compl / total * nSteps);
if tmp > step
fprintf(1, [repmat('\b', 1, strLength) '%s'], repmat('=', 1, tmp - step))
step = tmp;
ete = ceil(toc / step * (nSteps - step));
strLength = fprintf(1, [repmat(' ', 1, nSteps - step) '%s %3d%%, ETE %02d:%02d'], progStrArray(mod(step - 1, 4) + 1), floor(step * 100 / nSteps), floor(ete / 60), mod(ete, 60));
end
end
Jump to Line
Something went wrong with that request. Please try again.