## Copyright (C) 2005, Gerald Ebberink <address@hidden>
## 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA

## reads the csv's made by tektronix osciloscopes
## This function demands that the osciloscope is asked to "save all" and that there is a channel1 
## recoreded
## Since this read is slow, it also saves a octave bin file in the directory, so any subsequent
## reads are much faster.
## Useage:   data = Tekread(datadir)
## datadir is a string which gives the relative directory which is to be read
## data is structure returned with several members
##  data.WaveformX is the data of channel X
##  data.Time is the time vector
##  data.Index is a vector which has the same length as data.waveform1 and can be used to shift the figures a little

## Author: Gerald Ebberink <address@hidden>
## Keywords: file I/O tektronics
## Last Change: may 2005

function data = Tekread(datadir)



## if the directory ends with a slash 
## kill the slash, this is usefull later on
if datadir(end)=='/'
  datadir=datadir(1:end-1);
end;
	
## The filenames in the data dir are numbered by the osciloscope
## to get the right number the folowing is done
lscommand = sprintf('ls "%s/"', datadir);
filename = system(lscommand);
fileprepend = filename(1:7);

## now let us see if we have read this data before 
## and if we did read the data file instead of go into the slow process
if (findstr(filename,'.dat'))
  loadcommand = sprintf('load %s/zdata.dat',datadir);
  eval(loadcommand);
else
  % So it is the first time we read this data.
  
  % open first data file
  filename = sprintf('%s/%s1.csv',datadir,fileprepend);
  fid = fopen(filename,'rt');
  %if the data file exist go on
  if fid > 0 
    str = fgetl(fid); %get the first line
    dat = [];	%and reset dat
    while str~=-1
      idx = findstr(str,',');
    
      if findstr(str,'Vertical Scale') % search for the Vertical scale and put it in the data set
        data.VerticalScale(1) = str2num(str(idx(1)+1:idx(2)-1));
      end;
      
      if findstr(str,'Vertical Units') % search for the unit and put it in the data set
        data.VerticalUnit(1) = str(idx(1)+1:idx(2)-1);
      end;
  
      if findstr(str,'Vertical Offset') % search for the Offset number and again put it in the data set
          data.VerticalOffset(1) = str2num(str(idx(1)+1:idx(2)-1));
      end;				
  
      if findstr(str,'Horizontal Scale') % search for the Horizontal scale 
        data.HorizontalScale = str2num(str(idx(1)+1:idx(2)-1));
      end;
			
      if findstr(str, 'Horizontal Units') % find the Horizontal Units
        data.HorizontalUnit = str(idx(1)+1:idx(2)-1);
      end;
			
      Time(end+1) = str2num(str(idx(3)+1:idx(4)-1)); % Put the time data in the time array
      dat(end+1) = str2num(str(idx(4)+1:end-1)); % Put the data in the dat array
      str = fgetl(fid); % get next line
    end;
    fclose(fid);
    data.Time=Time(2:end); % put the time data in the data structure
    data.Waveform1=dat(1:end); % put the waveform data in the data structure
  end;

  for c=2:4 % for the next 3 channels
    filename = sprintf('%s/%s%i.csv',datadir,fileprepend,c); 
    fid = fopen(filename,'rt'); %open channel file
    if fid > 0 % if file exists
      str = fgetl(fid); %get first line
      dat=[]; % reset data structure
      while str~=-1
        idx = findstr(str,',');
		
        if findstr(str,'Vertical Units') % search for the unit and put it in the data set
          data.VerticalUnit(c) = str(idx(1)+1:idx(2)-1);
        end;
      
        if findstr(str,'Vertical Offset') % search for the Offset number and again put it in the data set
          data.VerticalOffset(c) = str2num(str(idx(1)+1:idx(2)-1));
        end;				
 
        if findstr(str,'Vertical Scale') % search for the Vertical scale and put it in the data set
          data.VerticalScale(c) = str2num(str(idx(1)+1:idx(2)-1));
        end;	

        dat(end+1) = str2num(str(idx(4)+1:end-1));
        str = fgetl(fid);
      end;
      switch (c)
        case (2) 
          data.Waveform2=dat(1:end); % if channel 2 put data in channel 2
        case (3)
          data.Waveform3=dat(1:end); % if channel 3 put data in channel 3
        case (4)
          data.Waveform4=dat(1:end); % if channel 4 put data in channel 4
      endswitch;

    end;
  end;
% Make a sample index (this is usefull in other programs)
data.Index=[1:1:size(data.Waveform1,2)];

%save data
savecommand=sprintf('save %s/zdata.dat data',datadir);
eval(savecommand);
end;