% loadrlr.m
%
% This Matlab 5.3/R11 script loads *.rlr raw data files written by
%		Ratlab 2000.
% Ratlab 2000 is the datataking program for the Caltech class Bi 162,
%		written in LabView.
%
% This script clobbers the following workspace variables:
%		datapath, workpath, filename, fid, message, line, paramname,
%		done, vals, nextval, filepos, rawlen
% Of these, it leaves datapath, workpath, and filename in the workspace,
%		but clears the rest before exiting
%
% This script also sets various other parameters and data variables
%		in the workspace, which is the whole point.
% See the code for details. ;-)
%
% David Kewley
% May 17, 2000
%
% Modified by Matt Cook and Dan Song the next day,
% changing 'single' to 'float32' and changing 'str2double' to 'str2num'
% so that it would run on our version of Matlab, 5.2.0.3084.
%

workpath = pwd;
if exist ('datapath')
   cd (datapath);
end

[filename, datapath] = uigetfile ('*.rlr', 'Select file to load:');

[fid, message] = fopen ([datapath filename], 'r');
if fid == -1
   disp (message);
else
   
   % all the file-reading and -parsing work is done now
   
   line = fgetl (fid);
   if ~isstr (line)
      disp ('Could not read file header.');
   else
      if line ~= 'RATLAB'
         disp ('File does not appear to be a Ratlab file.')
      else
         
         % clear all the workspace variables that we might read from the file
         
         clear FileVersion DateTime TrialRecTime TrialInterval RecRate
         clear NumRecChans NumRecSamp PreStimtime StimChanNames
         clear NumStimChans NumStimSamp StimRate StimData RawData
         
         % Loop over parameter lines in the header, after the initial
         %   'RATLAB'.
         % Set the parameter workspace variables that we find
         %   in the header.
         
         done = 0;
         while ~done
            line = fgetl (fid);
            [paramname, vals] = strtok (line);
            switch paramname
            case { 'Version', 'FileVersion' }
               FileVersion = str2num ( strtok (vals) );
            case 'DateTime'
               DateTime = vals;
            case 'TrialRecTime'
               TrialRecTime = str2num ( strtok (vals) );
            case 'TrialInterval'
               TrialInterval = str2num ( strtok (vals) );
            case 'RecRate'
               RecRate = str2num ( strtok (vals) );
            case 'NumRecChans'
               NumRecChans = str2num ( strtok (vals) );
            case 'NumRecSamp'
               NumRecSamp = str2num ( strtok (vals) );
            case 'PreStimTime'
               PreStimTime = str2num ( strtok (vals) );
            case 'StimChanNames'
               while (length(vals))
                  StimChanNames = cell (0);
                  [nextval, vals] = strtok (vals);
                  if strcmp (nextval, 'NoStim')
                     StimChanNames = {StimChanNames{:}, nextval};
                  end
               end
               NumStimChans = length (StimChanNames);
            case 'NumStimSamp'
               NumStimSamp = str2num ( strtok (vals) );
            case 'StimRate'
               StimRate = str2num ( strtok (vals) );
            case 'EndOfHeader'
               done = 1;
            otherwise
               disp (['Unknown parameter in header: ' paramname]);
            end
         end % end of while loop over parameter lines in header
         
         % close the file and reopen it as a stream of
         %   big-endian single-precision floats
         % but remember where we were, and start reading there
         
         filepos = ftell (fid);
         
         if fclose (fid)
            disp ('error closing the file');
         end
         
         [fid, message] = fopen ([datapath filename], 'r', 'ieee-be');
         
         if fid == -1
            disp (message);
         else
            
            fseek (fid, filepos, 'bof'); % move back to where we were
            
            % now read stim waveforms (if any)
            
            if exist ('NumStimSamp') & exist ('NumStimChans')
               
               if NumStimSamp > 0 & NumStimChans > 0
                  
                  % Note: the early lazy version of Ratlab 2000 datasaving
                  %   doesn't actually save the stim waveforms, even if
                  %   stimulation occurred.  In this case, the StimChanNames
                  %   will contain the appropriate stim channel names, but
                  %   NumStimSamp will be zero.  There is no stim data in
                  %   the file, so we should not attempt to read any.
                  
                  % read stim waveforms
                  
                  StimData = fread (fid, ...
                     [NumStimChans, NumStimSamp], 'float32');
               end
            end
            
            % get the length of the raw data portion of the file
            %   and calculate the number of trials
            
            filepos = ftell (fid);
            fseek (fid, 0, 'eof'); % go to end of file
            rawlen = ftell (fid) - filepos;
            fseek (fid, filepos, 'bof');
            NumTrials = rawlen / (NumRecChans * NumRecSamp);
            
            if NumTrials ~= fix (NumTrials)
               disp ('Raw data does not fit evenly into trials.');
            else
               
               % read raw data
               
               if NumRecChans == 1
                  RawData = fread (fid, [NumRecSamp, NumTrials], 'float32');
               else
                  RawData = fread (fid, ...
                     [NumRecChan, NumRecSamp, NumTrials], 'float32');
               end
            end
            
            
         end         
      end
   end
   
   if fclose (fid)
      disp ('error closing the file');
   end
end

% Clean up the temporary variables from the workspace and go back to
%   the directory we started in.

clear done fid line message nextval paramname vals filepos rawlen

cd (workpath);

% Bye!