eeg_load_scan_cnt.m

Matlab下的EEG处理程序库

function [x,y,tex,elec,cal,oth]=loadcnt(filen,elec,start,last);
% EEG_LOAD_SCAN_CNT - Load continuous NeuroScan data.
%
%	[X,Y,LAB,ELEC,CAL,OTH]=LOADCNT(FILEN,ELEC,START,LAST) elec defines 
%       which electrodes are read, size - rows data in y. If elec=[] then 
%	reads all channels data between start and end points. If elec
%	is string then only matched are read and with elec corresponding
%	channelnumbers are returned. lab is lab(elec). Text oth is ['rev  '
%	;'date ';'time ';'nchan';'rate ';'datas';'Chann';'size';'TeegT']
%	read by scanhead.
%
%	filen can be filename or file identifier. Because function scanelec,
%	scanhead are slow, variables lab, cal and oth are saved into 
%	file.mat file in directory "Headers". If *.cnt file is changed you 
%	have to remove file.mat for new parameters to be read.
%
%DIAGNOSTICS
%	Perhaps sensitive to different SynAmps parameters. Used global 
%	variable is DIRS.
%
%REFERENCES
%	Neurosoft. Structure of data headers. 1993.
%
%SEE ALSO
%	Uses scanhead, scanelec, showwait.
%
%EXAMPLES
%	                % load and show first 1000 points
%	[x,y,la,el,ca,ot]=loadcnt('x70001a1.cnt',[],1,1000);	
%	figure
%	plotdata(x,y,la,[50 50]);ot,xlabel('t (s');ylabel('100 uV');
%	print Help\loadcnt -djpeg
%
%	                % test loading large samples
%	[x,y1]=loadcnt('testec','FZ',1,30010);
%	[x,y2]=loadcnt('testec','FZ',30000,30100);[y1(30000:30010),y2]

% $Revision: 1.2 $ $Date: 2003/03/02 03:20:43 $

%Mention source when using or modifying these Shareware tools
%JVIR, [e-mail]
%JVIR,  7-Feb-1999 Saving into Headers location not Data Headers.
%JVIR,  3-Feb-1999 Modified for PCWIN Matlab 5.2.

%       J.Virkkala 30-Jun-94
%       J.Virkkala 12-Jan-95 Added parameter oth.
%       J.Virkkala 24-Jan-95 Saving header values into file.mat.
%       J.Virkkala 22-Feb-95 SynAmps working, Strings as file name.
%       J.Virkkala  3-Mar-95 Part of ScanUtil.
%	J.Virkkala 23-May-95 Still some problems with SynAmps.

global DIRS 
		% only integer positions accepted
start=round(start);last=round(last);
%*** FILENUMBER OR NAME AS PARAMETER ***
  if isstr(filen),
     file=fopen(filen,'r','l');
  else
     file=filen;
  end;
  if file==-1,errorr('hff','loadcnt');break;end
  name=[filename(file) '.mat'];
  if exist(name),eval(['load ' name]);else 
		% load electrodes calibration
  showwait('loading calibrations - %1.0f');
  [a,a,d]=scanelec(['lab';'bas';'sen';'cal'],'',file);
  n=size(d,1);
  nchannels=n/5;
  lab=d(2:5:n,:);
  for i=1:nchannels;
    cal(i,1)=eval(d(i*5-2,:));  % baseline
    cal(i,2)=eval(d(i*5-1,:));  % sensitivity
    cal(i,3)=eval(d(i*5,:));    % calibration
  end;
  [a,a,oth]=scanhead(['rev  ';'date ';'time ';'ncha ';'rate ';'datas';...
	'Chann';'size ';'TeegT'],file);
  bs=10*eval(oth(4,:));
  oth=putstr(mat2str(floor(eval(oth(6,:))/bs)*bs-1),oth,6,1);
  if ~exist('ele'),ele=[];end   % created by eegevent
  eval(['save ''Headers' DIRS name ''' cal lab oth ele']);   
  showwait('');
end; 
nchannels=size(lab,1);
	% if all electrodes
if isempty(elec);elec=1:nchannels;end;

	% if want to look match
if isstr(elec);
  e=[];
  for i=1:size(elec,1);
    p=strfind(lab,deblank(elec(i,:)));
	% if found
    if size(p)~=[0,0];
      p=p(:,1);
      if size(e,1)>size(p,1);
         p(size(e,1),1)=0;
      end;
      if size(e,1)==0;
%JVIR	   	p=p(find(p~=e)); % with same string possible diffent text
      end;
      p=p(1,1);
      size(e);
      if p;if size(e)==[0,0];e=p;else;e=[e;p];end;end;
    end;
  end;
	% names -> corresponding numbers
  elec=e';
else
  elec=elec(:)';
end;   

M=3000;y1=[];
%*** REPEATINGS FOR LONG SAMPLES ****
%JVIR, 4-Feb-1999
y=[];
x=[];
if (last-start)>M,
  for ind=start:M:last;
     e=ind+M-1;
     if e>last,e=last;end
     [x1,y1,tex,elec,cal,oth]=loadcnt(file,elec,ind,e);
     y=[y y1];
     x=[x x1];
   end
else
 
  l=eval(oth(6,:));
  if isempty(last),last=l;end
  if size(elec)==[0,0];return;end;
	% read data

%*** NEUROSCAN SYNAMPS ***
  if eval(oth(7,:))>1310000,	% ==1310720
    bs=10*nchannels;    % block size
    st=floor(start/bs)*bs;
    la=ceil(last/bs)*bs;
    
    x=1:(last-start)+1;
    fseek(file,900+nchannels*(75+st*2),-1);
    Yall=fread(file,[nchannels*10,(la-st)/10],'short');
	% only wanted 
    y(nchannels,(la-st))=0;
    for i=1:size(elec,2),
      el=elec(i);
      a=Yall((el-1)*10+1:el*10,:);
      y(el,:)=a(:)';
    end
    s=x+start-st;
%??? some problems with index ???
    if max(s)>size(y,2);s=s-1;end
    Yall=y(:,s);y=[];		% x+start-st
    I=ones(size(elec,2),size(x,2));
    y(1:size(elec,2),1:size(x,2))=sparse(diag(cal(elec,2)))*sparse(diag(cal(elec,3)))*...
	     (Yall(elec,x)-sparse(diag(cal(elec,1)))*I)./204.8;
  else

%*** NEUROSCAN FORMAT ***
				% fast but needs memory
    x=1:(last-start)+1;         
    fseek(file,900+nchannels*(75+(start-1)*2),-1);
    Yall=fread(file,[nchannels,(last-start+1)],'short');
	% only wanted channels          
    I=ones(size(elec,2),size(x,2));
    y(1:size(elec,2),1:size(x,2))=sparse(diag(cal(elec,2)))*sparse(diag(cal(elec,3)))*...
	     (Yall(elec,x)-sparse(diag(cal(elec,1)))*I)./204.8;
  end

  x=x+ones(1,size(x,2))*(start-1);
  x=x/eval(oth(5,:)); 		% xlabel in seconds
  tex=lab(elec,:);
end


%*** FILENUMBER OR NAME AS PARAMETER ***
  if isstr(filen),
    fclose(file);
  end;

%END OF LOADCNT