ctf_read_res4_coef.m

含有多种ICA算法的eeglab工具箱

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

% ctf_read_res4 - Read a CTF .res4 file
%
% ctf = ctf_read_res4( [folder], [VERBOSE])
% 
% This function reads the resource information from a CTF .ds folder.  This
% resource information must be read before reading the data from a .meg4
% file.
%
% INPUTS
%
%   folder: the .ds directory containing the data to be read.  With
%   no input, it will prompt with a gui folder locator.  If only
%   the folder is input, VERBOSE = 1.
%
%   VERBOSE = 1, display 'ctf.res4.generalSetup' structure (default)
%   VERBOSE = 0, do not display 'ctf.res4.generalSetup' structure
%
% OUTPUTS
%
%   ctf.folder: path of the .ds folder
%
%   ctf.header: data format header
%
%   ctf.res4.generalSetup: 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, pretriggerSamples,
%   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: 1.2 $ $Date: 2004/02/02 23:57:40 $

% Licence:  GNU GPL, no express or implied warranties
% Modified: 11/2003, Darren.Weber_at_radiology.ucsf.edu
%                    - modified from NIH code readresfile.m
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

ver = '$Revision: 1.2 $';
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 = 1; end

[rootpath,rootname] = fileparts(ctf.folder);
res4file = [rootname,'.res4'];
[res4fid,message] = fopen(res4file,'rb','s');

% 'ieee-be.l64' or 's' - IEEE floating point with big-endian byte ordering
%                        and 64 bit long data type.

if res4fid < 0,
  error(message);
end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% READ HEADER

fseek(res4fid, 0,-1);
ctf.res4.header = char(fread(res4fid,8,'char'))';

% check for the right format
if strmatch('MEG41RS',ctf.res4.header),
  % OK, we can handle this format
else
  msg = sprintf('May not read "%s" format correctly',ctf.res4.header);
  warning(msg);
end

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% READ GENERAL RESOURCES, byte offset = 8, byte size = 1840


%---DATE/TIME
fseek(res4fid, 778,-1);
ctf.res4.generalSetup.time = char(fread(res4fid,255,'char'))';
fseek(res4fid,1033,-1);
ctf.res4.generalSetup.date = char(fread(res4fid,255,'char'))';

%---NUMBER OF SAMPLES
fseek(res4fid,1288,-1);
ctf.res4.generalSetup.numberSamples = (fread(res4fid,1,'int32')');

%---NUMBER OF CHANNELS
fseek(res4fid,1292,-1);
ctf.res4.generalSetup.numberChannels = (fread(res4fid,1,'int16')');

%---SAMPLE RATE
fseek(res4fid,1296,-1);
ctf.res4.generalSetup.sampleRate = fread(res4fid,1,'double')';
ctf.res4.generalSetup.sampleMsec = 1000 / ctf.res4.generalSetup.sampleRate;
ctf.res4.generalSetup.sample_sec  =    1 / ctf.res4.generalSetup.sampleRate;

%---NUMBER OF TRIALS
fseek(res4fid,1312,-1);
ctf.res4.generalSetup.numberTrials = fread(res4fid,1,'int16')';
fseek(res4fid, 776,-1);
ctf.res4.generalSetup.numberTrials_averaged = fread(res4fid,1,'int16');

%---DURATION
fseek(res4fid,1304,-1);
ctf.res4.generalSetup.durationTotal = fread(res4fid,1,'double');
ctf.res4.generalSetup.durationTrial = ctf.res4.generalSetup.durationTotal / ctf.res4.generalSetup.numberTrials;

%---PRE_TRIG POINTS
fseek(res4fid,1316,-1);
ctf.res4.generalSetup.pretriggerSamples = fread(res4fid,1,'int32');
ctf.res4.generalSetup.pretriggerMsec = (ctf.res4.generalSetup.pretriggerSamples / ctf.res4.generalSetup.sampleRate) * 1000;

%---HEAD ZEROING
fseek(res4fid,1348,-1);
h_zero = fread(res4fid,1,'int32')';
no_yes = {'no','yes'};
ctf.res4.generalSetup.headZero = no_yes{h_zero+1};

%---RUN NAME
fseek(res4fid,1360,-1);
ctf.res4.generalSetup.runName = char(fread(res4fid,32,'char'))';

%---RUN TITLE
fseek(res4fid,1392,-1);
ctf.res4.generalSetup.runTitle = char(fread(res4fid,256,'char'))';

%---SUBJECT
fseek(res4fid,1712,-1);
ctf.res4.generalSetup.subject = char(fread(res4fid,32,'char'))';

%---OPERATOR
fseek(res4fid,1744,-1);
ctf.res4.generalSetup.operator = char(fread(res4fid,32,'char'))';

%---SENSOR FILE NAME
fseek(res4fid,1776,-1);
ctf.res4.generalSetup.sensorFileName = char(fread(res4fid,60,'char'))';


%---CALCULATE TIME ARRAYS (not read directly from the .res4 file)

% the time arrays must be based on increments of the sampleMsec
ctf.res4.generalSetup.timeMsec = [0:ctf.res4.generalSetup.numberSamples - 1]' * ctf.res4.generalSetup.sampleMsec;
ctf.res4.generalSetup.timeMsec = ctf.res4.generalSetup.timeMsec - ctf.res4.generalSetup.pretriggerMsec;

% 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
zeroIndex = find(abs(ctf.res4.generalSetup.timeMsec) == min(abs(ctf.res4.generalSetup.timeMsec)));
zeroValue = ctf.res4.generalSetup.timeMsec(zeroIndex);
if (-0.0001 < zeroValue) & (zeroValue < 0.0001),
  ctf.res4.generalSetup.timeMsec(zeroIndex) = 0;
end

ctf.res4.generalSetup.startMsec = ctf.res4.generalSetup.timeMsec(1);
ctf.res4.generalSetup.endMsec   = ctf.res4.generalSetup.timeMsec(end);

ctf.res4.generalSetup.timeSec  = ctf.res4.generalSetup.timeMsec / 1000;
ctf.res4.generalSetup.startSec = ctf.res4.generalSetup.timeSec(1);
ctf.res4.generalSetup.endSec   = ctf.res4.generalSetup.timeSec(end);


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% UNUSED, byte offset = 1840, byte size = 4

fseek(res4fid,1840,-1);
unused = fread(res4fid,1,'int32'); % read 4 byte int32 value

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% RUN DESCRIPTION, byte offset = 1844, byte size = 1 x rdl

% run description length (rdl)
fseek(res4fid,1836,-1);
runDescriptionLength = fread(res4fid,1,'int32');
% run description
fseek(res4fid,1844,-1);
ctf.res4.runDescription = char(fread(res4fid,runDescriptionLength,'char'));


%---PRINT RES4 VERBOSE INFORMATION
if VERBOSE,
  fprintf('...data format       : %s\n',ctf.res4.header);
  fprintf('...date collected    : %s\n',ctf.res4.generalSetup.date);
  fprintf('...time collected    : %s\n',ctf.res4.generalSetup.time);
  fprintf('...run name          : %s\n',ctf.res4.generalSetup.runName);
  fprintf('...run title         : %s\n',ctf.res4.generalSetup.runTitle);
  fprintf('...subject           : %s\n',ctf.res4.generalSetup.subject);
  fprintf('...run description   : %s\n',ctf.res4.runDescription);
  fprintf('...operator          : %s\n',ctf.res4.generalSetup.operator);
  fprintf('...number of channels: %d\n',ctf.res4.generalSetup.numberChannels);
  fprintf('...number of samples : %d per trial\n',ctf.res4.generalSetup.numberSamples);
  fprintf('...sample rate       : %g samples/sec\n',ctf.res4.generalSetup.sampleRate);
  fprintf('...number of trials  : %g trials (average of %g)\n',ctf.res4.generalSetup.numberTrials,ctf.res4.generalSetup.numberTrials_averaged);
  fprintf('...duration          : %g sec total\n',ctf.res4.generalSetup.durationTotal);
  fprintf('...duration          : %g sec / trial\n',ctf.res4.generalSetup.durationTrial);
  fprintf('...pretrigger points : %g samples\n',ctf.res4.generalSetup.pretriggerSamples);
  fprintf('...pretrigger msec   : %g msec\n',ctf.res4.generalSetup.pretriggerMsec);
  fprintf('...sensor file name  : %s\n',ctf.res4.generalSetup.sensorFileName);
  fprintf('...head zeroing      : %s\n',ctf.res4.generalSetup.headZero);
end



%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% NUMBER OF FILTERS, byte offset = 1844 + rdl, byte size = 2

offset = 1844 + runDescriptionLength;
fseek(res4fid,offset,-1);
ctf.res4.numberFilters = fread(res4fid,1,'int16');

% this is 'nf' in CTF file format pdf, used for calculating file byte offset
nf = ctf.res4.numberFilters;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% FILTER INFORMATION, byte offset = 1846 + rdl, byte size = variable

% this is 'b' in CTF file format pdf, used for calculating file byte offset
b = 1846 + runDescriptionLength;
fseek(res4fid,b,-1);


% this is 'fi' in CTF file format pdf, used for calculating file byte offset
fi = 0;
% this is 'p' & 'np' in CTF file format pdf
p = 0; np = 0;

for i = 1:ctf.res4.numberFilters,
  
  fi = i - 1;
  ctf.res4.filter(i).frequency = fread(res4fid,1,'double');
  ctf.res4.filter(i).class     = fread(res4fid,1,'int32');
  ctf.res4.filter(i).type      = fread(res4fid,1,'int32');
  
  if i > 1,
    p = p + ( ctf.res4.filter(i-1).numberParameters * 8 );
  end
  np = np + ( ctf.res4.filter(i).numberParameters * 8 );
  
  ctf.res4.filter(i).numberParameters = fread(res4fid,1,'int16');
  ctf.res4.filter(i).parameters = fread(res4fid,ctf.res4.filter(i).numberParameters,'double');
  
end

% this is 'f' in CTF file format pdf
f = ( nf * 18 ) + ( np * 8 );


%---PRINT FILTER INFORMATION