read_eas.m

% read_eas : reads an GEO EAS formatted file into Matlab.
%
% Call [data,header,title]=read_eas(filename);
%
% TMH (tmh@gfy.ku.dk)
%
function [data,header,txt_title,dim,txtdata,txtheader]=read_eas(filename);
   fid=fopen_retry(filename,'r');
   txt_title=fgetl(fid);
   try
       id1=strfind(txt_title,'(');
       id2=strfind(txt_title,')');
       dims=txt_title( (id1+1):(id2-1) );
       
       j=findstr(dims,'x');
       dim.nx=str2num(dims(1:(j(1)-1)));
       dim.ny=str2num(dims((j(1)+1):(j(2)-1)));
       dim.nz=str2num(dims((j(2)+1):length(dims)));
   catch
       dim=[];
   end
   
   %disp(txt_title);
   l=fgetl(fid);
   % next 3 lines to satisfy sisim.f
   if  isempty(str2num(l))
     l=fgetl(fid);
   end
   nc=str2num(l);
   for i=1:nc,
     header{i}=strip_space(fgetl(fid));
   end
   header=regexprep(header,char(9),'');
   nvar=length(header);
   fpos_start=ftell(fid);
   use_alt=0;
   txtdata=[];
   txtheader=[];
   try
     data=fscanf(fid,'%f',[inf]);
     ndata=length(data)./length(header);
     data=reshape(data(:),nvar,ndata)';
   catch
     use_alt=1;
   end
   
   % If no data has been read, use alternate method
   if isempty(data), use_alt=1; end
   if use_alt==1,
     clear data
     disp('Trying to read data into cell structure')
     fseek(fid,fpos_start,'bof');
     i=0;
     while ~(feof(fid));
       i=i+1;
       if (i/1000)==round(i/1000),disp(sprintf('%d',i));end
       s=fgetl(fid);
       % Strip line into values seperated by space(s).
       l = {};
       while (length(s) > 0)
         [t,s] = strtok(s);
         l = {l{:}, t};
       end
%       disp(i)
       txtdata_header=[];
       h1=0;h2=0;
       for i2=1:min(length(l),nc)
         val=l{i2};
         try
           if (~isempty((str2num(val))))&(~strcmp(val,'i'))           
             val=str2num(val);
             data.(header{i2})(i)=val;
             h1=h1+1;data_header{h1}=header{i2};
           else           
             if ~isempty(val)
               txtdata.(header{i2}){i}=val;           
               h2=h2+1;txtdata_header{h2}=header{i2};
             else
               % disp(sprintf('data line %d pos %d: Empty Value',i,i2))
             end
           end
         catch
             disp('READ ERROR')
         end
       end
     end
     % convert data to normal eas matrix
     nh=length(data_header);
     nd=length(data.(header{1}));
     data_out=zeros(nd,nh);
     for i=1:nh;
         ndh=length(data.(data_header{i}));
         data_out(1:ndh,i)=data.(data_header{i})(1:ndh);
     end
     data=data_out;
     header=data_header;
     txtheader=txtdata_header;
   end
   
   
   
   fclose(fid);