ctf_read_res4.m

含有多种ICA算法的eeglab工具箱

function [ctf] = ctf_read_res4(folder,VERBOSE,COEFS);

% ctf_read_res4 - Read a CTF .res4 file
%
% ctf = ctf_read_res4( [folder], [verbose], [coefs])
% 
% This function reads the resource information from a CTF .ds folder.  This
% resource information must be read before reading the .meg4 data file.
% All input arguments are optional.
%
% INPUTS
%
%   folder: the .ds directory containing the data to be read.  With
%           no input, it will prompt with a gui folder locator.
%
%   verbose: If verbose = 1, display 'ctf.setup' structure (default)
%            If verbose = 0, do not display 'ctf.setup' structure
%
%   coefs: an option to read the sensory coefficients, which give the
%          weights for calculation of synthetic 2nd or 3rd order
%          gradiometers.
%          If coefs = 1, read the sensor coefficients
%          If coefs = 0, do not read the sensor coefficients (default)
% 
% OUTPUTS
%
%   ctf.folder - path of the .ds folder
%
%   ctf.res4.file - data file path/name
%   ctf.res4.header - data format header
%
%   ctf.setup - a header structure consisting of date, time, run name, run
%   title, subject, run description, operator, number of channels, number
%   of samples, sample rate, number of trials, duration, pretrigger_samples,
%   sensor filename, head zeroing, and number of filters.
%   
%   ctf.sensor.index - a sensor structure consisting of EEG sensors, MEG
%   sensors, reference sensors, and other sensors.
%   
%   ctf.sensor.info - a structure with gain and offset information consisting
%   of proper gain, Q gain, io gain, io offset, and index.
%
%      <>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
%      <                                                      >
%      <                    DISCLAIMER:                       >
%      <                                                      >
%      < THIS PROGRAM IS INTENDED FOR RESEARCH PURPOSES ONLY. >
%      < THIS PROGRAM IS IN NO WAY INTENDED FOR CLINICAL OR   >
%      <                    OFFICIAL USE.                     >
%      <                                                      >
%      <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>
%

% $Revision: 1.12 $ $Date: 2004/07/18 06:10:17 $

% Copyright (C) 2003  Darren L. Weber
% 
% 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.

% Modified: 11/2003, Darren.Weber_at_radiology.ucsf.edu
%                    - modified from NIH code readresfile.m
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

ver = '$Revision: 1.12 $';
fprintf('\nCTF_READ_RES4 [v %s]\n',ver(11:15)); tic;

if ~exist('folder','var'),
  ctf = ctf_folder;
else
  ctf = ctf_folder(folder);
end

if ~exist('VERBOSE','var'), VERBOSE = true; end
if ~exist('COEFS','var'), COEFS = false; end

[folderPath,folderName,folderExt] = fileparts(ctf.folder);
ctf.res4.file = findres4file(ctf.folder);

%----------------------------------------------------------------
% open the data file

[fid,message] = fopen(ctf.res4.file,'rb','ieee-be.l64');
if fid < 0, error('cannot open .res4 file'); end


%-------------------------------------------------------------
% READ HEADER

fseek(fid,0,-1);
ctf.res4.header = char(fread(fid,8,'char'))';

% check for the right format
if strmatch('MEG41RS',ctf.res4.header),
  % OK, we can handle this format
else
  msg = sprintf('This function is designed to read MEG41RS format.\nIt may not read "%s" format correctly',ctf.res4.header);
  warning(msg);
end


%-------------------------------------------------------------
% READ SETUP


%---DATE/TIME
fseek(fid, 778,-1);
ctf.setup.time = char(fread(fid,255,'char'))';
fseek(fid,1033,-1);
ctf.setup.date = char(fread(fid,255,'char'))';

%---NUMBER OF SAMPLES
fseek(fid,1288,-1);
ctf.setup.number_samples = (fread(fid,1,'int32')');

%---NUMBER OF CHANNELS
fseek(fid,1292,-1);
ctf.setup.number_channels = (fread(fid,1,'int16')');

%---SAMPLE RATE
fseek(fid,1296,-1);
ctf.setup.sample_rate = fread(fid,1,'double')';
ctf.setup.sample_msec = 1000 / ctf.setup.sample_rate;
ctf.setup.sample_sec  =    1 / ctf.setup.sample_rate;

%---NUMBER OF TRIALS
fseek(fid,1312,-1);
ctf.setup.number_trials = fread(fid,1,'int16')';
fseek(fid, 776,-1);
ctf.setup.number_trials_averaged = fread(fid,1,'int16');

%---DURATION
fseek(fid,1304,-1);
ctf.setup.duration_total = fread(fid,1,'double');
ctf.setup.duration_trial = ctf.setup.duration_total / ctf.setup.number_trials;

%---PRE_TRIG POINTS
fseek(fid,1316,-1);
ctf.setup.pretrigger_samples = fread(fid,1,'int32');
ctf.setup.pretrigger_msec = (ctf.setup.pretrigger_samples / ctf.setup.sample_rate) * 1000;

%---HEAD ZEROING
fseek(fid,1348,-1);
h_zero = fread(fid,1,'int32')';
no_yes = {'no','yes'};
ctf.setup.head_zero = no_yes{h_zero+1};

%---RUN NAME
fseek(fid,1360,-1);
ctf.setup.run_name = char(fread(fid,32,'char'))';

%---RUN TITLE
fseek(fid,1392,-1);
ctf.setup.run_title = char(fread(fid,256,'char'))';

%---SUBJECT
fseek(fid,1712,-1);
ctf.setup.subject = char(fread(fid,32,'char'))';

%---OPERATOR
fseek(fid,1744,-1);
ctf.setup.operator = char(fread(fid,32,'char'))';

%---SENSOR FILE NAME
fseek(fid,1776,-1);
ctf.setup.sensor_file_name = char(fread(fid,60,'char'))';

%---RUN DESCRIPTION & FILTERS
fseek(fid,1836,-1);
run_size = fread(fid,1,'int32');
fseek(fid,1844,-1);
ctf.setup.run_description = char(fread(fid,run_size,'char'));

ctf.setup.number_filters = fread(fid,1,'int16');

for i = 1:ctf.setup.number_filters,
  ctf.setup.filters(i).freq     = fread(fid,1,'double');
  ctf.setup.filters(i).class    = fread(fid,1,'int32');
  ctf.setup.filters(i).type     = fread(fid,1,'int32');
  ctf.setup.filters(i).numparam = fread(fid,1,'int16');
  ctf.setup.filters(i).params   = fread(fid,ctf.setup.filters(i).numparam,'double');
end

if(COEFS)
    b = 1846 + run_size;
    if(ctf.setup.number_filters == 0)
        np = 0;
    else
        np = ctf.setup.filters.numparam;
        warning('3rd gradient + hardware filter parameters not fully tested! let''s see what happens... :)');
    end
    nf = ctf.setup.number_filters;
    f = ( nf * 18 ) + ( np * 8 );
    offset = b + f + ctf.setup.number_channels * 1360;
end


%-------------------------------------------------------------
% CREATE TIME ARRAYS

% the time arrays must be based on increments of the sample_msec
ctf.setup.time_msec = [0:ctf.setup.number_samples - 1]' * ctf.setup.sample_msec;
ctf.setup.time_msec = ctf.setup.time_msec - ctf.setup.pretrigger_msec;

% adjust the sample point closest to zero so that it is zero, if it
% is reasonably close to zero, say within 3 decimal places for msec timing
zero_index = find(abs(ctf.setup.time_msec) == min(abs(ctf.setup.time_msec)));
zero_value = ctf.setup.time_msec(zero_index);
if (-0.0001 < zero_value) & (zero_value < 0.0001),
  ctf.setup.time_msec(zero_index) = 0;
end

ctf.setup.start_msec = ctf.setup.time_msec(1);
ctf.setup.end_msec   = ctf.setup.time_msec(end);

ctf.setup.time_sec  = ctf.setup.time_msec / 1000;
ctf.setup.start_sec = ctf.setup.time_sec(1);
ctf.setup.end_sec   = ctf.setup.time_sec(end);


%-------------------------------------------------------------
% PRINT SETUP
if VERBOSE,
  ctf_print_setup(ctf);
end





%-------------------------------------------------------------
% READ SENSOR INFORMATION

ctf.sensor.info = struct(...
  'proper_gain',[],...
  'q_gain',[],...
  'io_gain',[],...
  'io_offset',[],...
  'index',[],...
  'extra',[],...
  'label',[],...
  'grad_order_no',[]);

% read channel names (not trivial!)
for chan = 1:ctf.setup.number_channels,
  temp = fread(fid,32,'char');
  temp(temp>127) = 0;
  temp(temp<0) = 0;