christopherh@1: %
christopherh@1: %CHORD2PITCHCLASSES Convert chord symbol to array of pitch classes
christopherh@1: % 
christopherh@1: % [pitchclasses, bassclass, success, errormessage] = chord2pitchclasses(chordsymbol, {inversion}, {verbose})
christopherh@1: % 
christopherh@1: % Converts a chord symbol to an array of integer pitch class values and a
christopherh@1: % bass pitch class value. Pitch class values are referenced w.r.t. C = 0.
christopherh@1: %
christopherh@1: % In the case of the 'no chord' symbol 'N' function returns an empty array
christopherh@1: %
christopherh@1: % Success = 1 if notes extracted from chordsymbol correctly, 0 otherwise.
christopherh@1: % 
christopherh@1: % If optional argument 'verbose' is 1, function prints any errormessage to 
christopherh@1: % the screen.
christopherh@1: % 
christopherh@1: % calls:    chord2notes
christopherh@1: %           notes2pitchclasses
christopherh@1: % 
christopherh@1: % returns:  pitchclasses (array of integers)
christopherh@1: %           bassclass (integer)           
christopherh@1: %           success (boolean)
christopherh@1: %           errormessage (string)
christopherh@1: %
christopherh@1: %
christopherh@1: % Author: Christopher Harte,  March 2009
christopherh@1: % 
christopherh@1: % Copyright: Centre for Digital Music, Queen Mary University of London 2005 
christopherh@1: %
christopherh@1: % This file is part of the C4DM Chord Toolkit V2.0  
christopherh@1: %
christopherh@1: % The C4DM Chord Toolkit is free software; you can redistribute it and/or 
christopherh@1: % modify it under the terms of the GNU General Public License as published 
christopherh@1: % by the Free Software Foundation; either version 2 of the License, or
christopherh@1: % (at your option) any later version.
christopherh@1: %
christopherh@1: % The C4DM Chord Toolkit is distributed in the hope that it will be useful,
christopherh@1: % but WITHOUT ANY WARRANTY; without even the implied warranty of
christopherh@1: % MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
christopherh@1: % GNU General Public License for more details.
christopherh@1: %
christopherh@1: % You should have received a copy of the GNU General Public License
christopherh@1: % along with the C4DM Toolkit; if not, write to the Free Software
christopherh@1: % Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
christopherh@1: 
christopherh@1: %             
christopherh@1: function [pitchclasses, bassclass, success, errormessage] = chord2pitchclasses(chordsymbol, inversion, verbose)
christopherh@1: 
christopherh@1: % set verbose default to 0
christopherh@1: if nargin < 3
christopherh@1:     verbose = 0;
christopherh@1: end
christopherh@1: 
christopherh@1: if nargin < 2
christopherh@1:     inversion = 1;
christopherh@1: end
christopherh@1: 
christopherh@1: errormessage = '';
christopherh@1: mainlist = '';
christopherh@1: success = 1;
christopherh@1: pitchclasses = [];
christopherh@1: bassclass = '';
christopherh@1: contains = 0;
christopherh@1:  
christopherh@1: % get constituent notes
christopherh@1: [chordnotes, bassnote, success, errormessage] = chord2notes(chordsymbol);
christopherh@1: 
christopherh@1: %convert notes and bass to pitch classes
christopherh@1: if success && ~isempty(chordnotes)
christopherh@1: % find pitchclasses of notes
christopherh@1: [pitchclasses, success, errormessage] = notes2pitchclasses(chordnotes);
christopherh@1: end
christopherh@1: 
christopherh@1: if success && ~isempty(bassnote)
christopherh@1: [bassclass, success, errormessage] = note2pitchclass(char(bassnote));
christopherh@1: 
christopherh@1:     % check if the bass class is already part of the chord
christopherh@1:     if success
christopherh@1:         ilength = length(pitchclasses);
christopherh@1: 
christopherh@1:         contains = 0;
christopherh@1: 
christopherh@1:         for index = 1:ilength
christopherh@1:             if bassclass == pitchclasses(index)
christopherh@1:                 contains = 1;
christopherh@1:                 if inversion
christopherh@1:                     pitchclasses = [pitchclasses(index:end) pitchclasses(1:index-1)];
christopherh@1:                 end
christopherh@1:             end
christopherh@1:         end
christopherh@1: 
christopherh@1:     end
christopherh@1: 
christopherh@1:     %if the note is not already part of the chord then insert it
christopherh@1:     if ~contains
christopherh@1: 
christopherh@1:         % if inversion=1 then insert at start of pitchclasses
christopherh@1:         if inversion
christopherh@1:             pitchclasses = [bassclass pitchclasses];
christopherh@1:         else
christopherh@1:             relpc = mod(pitchclasses-pitchclasses(1),12);
christopherh@1:             relbass = mod(bassclass-pitchclasses(1),12);
christopherh@1:             
christopherh@1:             i=0;
christopherh@1:             while(i<ilength)
christopherh@1:                 if relbass<relpc(i+1)
christopherh@1:                     break
christopherh@1:                 else
christopherh@1:                     i=i+1;
christopherh@1:                 end
christopherh@1:             end
christopherh@1: 
christopherh@1:             if i==ilength
christopherh@1:                 pitchclasses = [pitchclasses bassclass];
christopherh@1:             else
christopherh@1:                 pitchclasses = [pitchclasses(1:i) bassclass pitchclasses(i+1:end)];
christopherh@1:             end
christopherh@1:             
christopherh@1:             
christopherh@1:             
christopherh@1:             
christopherh@1:         end
christopherh@1:         
christopherh@1:     end
christopherh@1: 
christopherh@1: end    
christopherh@1:     
christopherh@1: 
christopherh@1: 
christopherh@1: if success == 0
christopherh@1:     errormessage = [errormessage sprintf(['Error in chord2pitchclasses: Couldn''t convert chord "' chordsymbol '"\n'])];   
christopherh@1:     if verbose ==1
christopherh@1:        fprintf(1,errormessage);
christopherh@1:     end
christopherh@1:        
christopherh@1:        
christopherh@1: end  
christopherh@1:     
christopherh@1:     
christopherh@1: