plx_waves

 plx_waves(filename, channel, unit): Read waveform data from a .plx file

 [n, npw, ts, wave] = plx_waves(filename, channel, unit)

 INPUT:
   filename - if empty string, will use File Open dialog
   channel - 1-based channel number
   unit  - unit number (0- invalid, 1-4 valid)
 OUTPUT:
   n - number of waveforms
   npw - number of points in each waveform
   ts - array of timestamps (in seconds) 
   wave - array of waveforms [npw, n], raw a/d values

0001 function [n, npw, ts, wave] = plx_waves(filename, ch, u)
0002 % plx_waves(filename, channel, unit): Read waveform data from a .plx file
0003 %
0004 % [n, npw, ts, wave] = plx_waves(filename, channel, unit)
0005 %
0006 % INPUT:
0007 %   filename - if empty string, will use File Open dialog
0008 %   channel - 1-based channel number
0009 %   unit  - unit number (0- invalid, 1-4 valid)
0010 % OUTPUT:
0011 %   n - number of waveforms
0012 %   npw - number of points in each waveform
0013 %   ts - array of timestamps (in seconds)
0014 %   wave - array of waveforms [npw, n], raw a/d values
0015 
0016 if(nargin ~= 3)
0017    disp('3 input arguments are required')
0018    return
0019 end
0020 
0021 n = 0;
0022 npw = 0;
0023 ts = 0;
0024 wave = 0;
0025 
0026 if(isempty(filename))
0027    [fname, pathname] = uigetfile('*.plx', 'Select a plx file');
0028     filename = strcat(pathname, fname);
0029 end
0030 
0031 fid = fopen(filename, 'r');
0032 if(fid == -1)
0033     disp('cannot open file');
0034    return
0035 end
0036 
0037 disp(strcat('file = ', filename));
0038 
0039 % read file header
0040 header = fread(fid, 64, 'int32');
0041 freq = header(35);  % frequency
0042 ndsp = header(36);  % number of dsp channels
0043 nevents = header(37); % number of external events
0044 nslow = header(38);  % number of slow channels
0045 npw = header(39);  % number of points in wave
0046 npr = header(40);  % number of points before threshold
0047 tscounts = fread(fid, [5, 130], 'int32');
0048 wfcounts = fread(fid, [5, 130], 'int32');
0049 evcounts = fread(fid, [1, 512], 'int32');
0050 
0051 % skip variable headers
0052 fseek(fid, 1020*ndsp + 296*nevents + 296*nslow, 'cof');
0053 
0054 record = 0;
0055 wave = zeros(npw, 1);
0056 wf = zeros(npw, 1);
0057 
0058 % read data records
0059 while feof(fid) == 0
0060    type = fread(fid, 1, 'int16');
0061     upperbyte = fread(fid, 1, 'int16');
0062     timestamp = fread(fid, 1, 'int32');
0063     channel = fread(fid, 1, 'int16');
0064    unit = fread(fid, 1, 'int16');
0065    nwf = fread(fid, 1, 'int16');
0066    nwords = fread(fid, 1, 'int16');
0067    toread = nwords;
0068    if toread > 0
0069       wf = fread(fid, [toread, 1], 'int16');
0070    end
0071    if toread > 0
0072        if type == 1
0073          if channel == ch 
0074             if unit == u
0075             n = n + 1;
0076                ts(n) = timestamp/freq;
0077                wave(:, n) = wf;
0078             end
0079            end
0080        end
0081    end
0082    
0083    record = record + 1;
0084    if feof(fid) == 1
0085       break
0086    end
0087    
0088 end
0089 disp(strcat('number of waveforms = ', num2str(n)));
0090 
0091 fclose(fid);