diff chordtools/chord2notes.m @ 1:8973548174c1 tip

adding tools to repo

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/chordtools/chord2notes.m	Mon May 06 14:43:47 2013 +0100
@@ -0,0 +1,167 @@
+%
+%CHORD2NOTES Convert chord symbol to list of constituent notes
+% 
+% [chordnotes, bassnote, success, errormessage] = chord2notes(chordsymbol, {verbose})
+% 
+% Converts a chord symbol to a cell array of note strings and a bassnote string.
+%
+% In the case of the 'no chord' symbol 'N' function returns an empty array
+%
+% Success = 1 if notes extracted from chordsymbol correctly, 0 otherwise.
+% 
+% If optional argument 'verbose' is 1, function prints any errormessage to 
+% the screen.
+% 
+% calls:    getnoteinfo
+%           parsenote
+%           addshort2list
+%           interval2note
+% 
+% returns:  chordnotes  (cell array of note strings)
+%           bassnote (string)           
+%           success (boolean)
+%           errormessage (string)
+%
+%
+% Author: Christopher Harte,  March 2009
+% 
+% Copyright: Centre for Digital Music, Queen Mary University of London 2005 
+%
+% This file is part of the C4DM Chord Toolkit V2.0  
+%
+% The C4DM Chord Toolkit 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.
+%
+% The C4DM Chord Toolkit 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 the C4DM Toolkit; if not, write to the Free Software
+% Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+
+%             
+function [chordnotes, bassnote, success, errormessage] = chord2notes(chordsymbol, inversion, verbose)
+
+%set default inversion to 0
+if nargin < 2
+    inversion = 0;
+end
+
+% set verbose default to 0
+if nargin < 3
+    verbose = 0;
+end
+
+errormessage = '';
+mainlist = '';
+success = 1;
+chordnotes = [];
+bassnote = '';
+
+% parse the chordsymbol
+[rootnote,shorthand,interval_list,bass, success, errormessage] = getchordinfo(chordsymbol);
+
+
+
+
+%if 'no chord' then return N
+if (success == 1)
+    
+
+    
+    if rootnote == 'N'
+        
+        chordnotes = {};
+    else
+
+
+        % combine shorthand and interval_list and obtain note names for each
+        % interval
+        if success
+
+            [mainlist, success, errormessage] = addshort2list(shorthand, interval_list);
+
+            if success
+
+                % convert list of intervals to list of notes 
+                [chordnotes,success,errormessage] = intervals2notes(mainlist,rootnote);
+                 
+            end
+
+        end
+
+        % Now find the bass note
+
+        if success
+
+            if ~isempty(bass)
+
+                [bassnote,success,errormessage] = interval2note(bass, rootnote);
+    
+                if inversion
+                    % if the bass note is a member of the chord
+                    if length(intersect(bassnote,chordnotes))==1
+                        %rotate the chord until the bassnote is the first
+                        %element
+                        for i=1:length(chordnotes)
+                           if strcmp(chordnotes{1},bassnote)
+                               break
+                           else
+                               chordnotes = [chordnotes(2:end); chordnotes(1)];
+                           end                           
+                            
+                        end
+                     
+                    else
+                        % insert the bassnote at the start of the chord
+
+                        chordnotes = [bassnote; chordnotes];
+
+
+                    end
+                end
+%                 if success
+%                     
+%                     ilength = length(chordnotes);
+%                     index = 1;
+%                     
+%                     % check if the bass note is included in the other chord notes 
+%                     while index<=ilength
+%                         if char(bassnote) == char(chordnotes(index))
+%                             index = ilength +1;
+%                             contains = 1;
+%                         else
+%                             contains = 0;
+%                             index = index +1;
+%                         end
+%                     end
+%                     
+%                     if contains == 0
+%                         
+%                        % chordnotes = [bassnote; chordnotes];
+%                     end
+%                 end
+            else
+                bassnote = chordnotes(1);
+            end
+
+
+        end
+    end
+end
+
+if success == 0
+    errormessage = [errormessage sprintf(['Error in chord2notes: Couldn''t convert chord "' chordsymbol '"\n'])];   
+    if verbose ==1
+       fprintf(1,errormessage);
+    end
+       
+       
+end  
+    
+    
+    
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