[Paparazzi-devel] Log parser for Matlab

[Andreas Gaeb]

Hello everybody,

I've created a new Matlab log parser in case anybody is still working
with that for reviewing logs. It is a bit faster than PprzLogReader_1_0,
more flexible and can read any type of message present in a log file. It
has been tested with Matlab 7.1 and R2009a, so it should also work with
releases in between. Examples of usage are given in the file.

I'll also be having a look at Roman Krashanitsa's log plotter GUI which
seems to be broken with actual SVN log files.

I tried to upload the script to the wiki, but this seems to accept only
image files, so I'm attaching it here. Maybe someone can add it to the SVN.

Regards,
        Andreas

function s = log2struct(logfilename)
% parse a PPRZ log file
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% function s = log2struct(logfilename)
% Parses a log data file from the Paparazzi ground station into a 
% Matlab variable. The log is sorted by aircraft ID and message ID.
% Parsing the log definition file (xx.log) is not required.
% 
% Argument
% The name of the log data file to be parsed.
% May be omitted, in which case a file open dialog is used.
% 
% Returns
% A struct of dimension 1 x nAircraft
% For each type of message received there is a substruct with the fields
% timestamp and contents as arrays over time. The columns of the contents
% array correspond to the message's data fields as defined in messages.xml.
%
% Example
% >> % 3D plot of the trajectory of aircraft #1
% >> s = log2struct('09_08_26__14_18_29.data');
% >> plot3(s(1).GPS.content(:,2), s(1).GPS.content(:,3),s(1).GPS.content(:,5))
% >> % what did the servos do?
% >> plot (s(1).ACTUATORS.timestamp, s(1).ACTUATORS.content)
% 
% Known Bugs
% The method fails when the number of data elements for one message type
% changes during the log file, as may happen when the configuration file is
% changed in between or with arrays of variable size.
% 
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Author: Andreas Gaeb
% Created:  27-Aug-2009
% $Id$
%
% Copyright (C) 2009 Andreas Gaeb
%
% This file is part of paparazzi.
%
% paparazzi 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, or (at your option)
% any later version.
%
% paparazzi 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 paparazzi; see the file COPYING.  If not, write to
% the Free Software Foundation, 59 Temple Place - Suite 330,
% Boston, MA 02111-1307, USA.
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

persistent log2struct_old_working_dir

% no arguments? open dialog
if nargin < 1
  [filename, pathname] = uigetfile(...
    {'*.data', 'Paparazzi log data files (*.data)'}, ...
    'Open data file', ...
    log2struct_old_working_dir);
  if ~filename, return, end
        logfilename = fullfile(pathname, filename);
  log2struct_old_working_dir = pathname; 
  % display the filename for copy/paste
  disp (['parsing ' logfilename '...']);
end

fid = fopen(logfilename);
if fid == -1
  error('File %s not found', logfilename);
end

try
  % read everything as timestamp, A/C ID, msg name and msg contents
  C = textscan(fid, '%f %u %s %[^\n]');
  
  if isempty(C{1})
    error ('File %s does not seem to be a Paparazzi log data file.', 
logfilename);
  end
  
  timestamp = C{1};
  aircraftID = C{2};
  msgName = C{3};
  msgContent = C{4};
  
  % find s which messages have been sent
  uniqueMsgs = unique(msgName);
  nMsg = size(uniqueMsgs,1);
  
  % find s which aircraft sent something
  uniqueAC = unique(aircraftID);
  nAC = size(uniqueAC,1);
  
  % distribute the messages to their sending aircraft
  for iAC = nAC:-1:1 % counting backwards eliminates preallocation
    % the ID of ith aircraft
    acID = uniqueAC(iAC);
    s(iAC).AIRCRAFT_ID = acID;
    
    % the indices of all messages send by ith aircraft 
    allMsgsFromThisAircraft = (aircraftID == uniqueAC(iAC)); 
    timestampFromThisAircraft = timestamp(allMsgsFromThisAircraft);
    msgNameFromThisAircraft = msgName(allMsgsFromThisAircraft);
    msgContentFromThisAircraft = msgContent(allMsgsFromThisAircraft);
    
    % for each message name
    for iMsg = 1:nMsg
      theMsgName = uniqueMsgs{iMsg};
      
      % when was this special message sent by the ith aircraft?
      thisMsgFromThisAircraft = strmatch(...
        theMsgName, msgNameFromThisAircraft, 'exact');
      
      % record with timestamp and contents
      s(iAC).(theMsgName).timestamp = ...
        timestampFromThisAircraft(thisMsgFromThisAircraft);
      [s(iAC).(theMsgName).content, status] = str2num(char(...
        msgContentFromThisAircraft(thisMsgFromThisAircraft))); %#ok<ST2NM>
      if ~status && ~strcmp(theMsgName, 'PONG')
        warning('Paparazzi:log2struct:EmptyContent', ...
          'Could not read contents of %s message from aircraft #%i', ...
          theMsgName, acID);
        continue;
      end
    end  
    
  end
  
  fclose (fid);
  
catch theError
  fclose(fid);
  rethrow(theError);
end