comparison chordtools/degree2semitone.m @ 1:8973548174c1 tip

adding tools to repo

+%
+% DEGREE2SEMITONE
+% 
+% [semitone, success, errormessage] = degree2semitone(degree, accidental, {verbose})
+% 
+% Convert a degree and accidentals pair to a semitone value
+% 
+% Success = 1 if degree converted correctly, 0 otherwise.
+% 
+% If optional argument 'verbose' is 1, function prints any errormessage to 
+% the screen.
+% 
+% returns:  semitone (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 [semitone, success, errormessage] = degree2semitone(degree, accidentals, verbose)
+
+if nargin < 3 
+    % verbose defaults 0
+    verbose = 0;
+end
+
+errormessage = '';
+
+% semitone equivalents for degrees
+%             degree   1,2,3,4,5,6,7         
+%semitonetranslation = [0,2,4,5,7,9,11];
+
+semitone = 0;
+
+success = 1;
+
+if (degree > 0) && (degree < 50)
+
+% semitone value is the number of semitones equivalent to the degree
+% added to the number of accidentals (sharps are positive, flats are
+% negative) and the number of octaves above the reference note to
+% account for extensions 
+
+%semitone = semitonetranslation(mod(degree,8) + fix(degree/8)) + accidentals + 12*fix(degree/8);
+
+semitone = 2*mod(degree-1,7) - floor((mod(degree-1,7)+1)/4) + 12*floor((degree-1)/7)+ accidentals; 
+
+else
+    success = 0;
+    
+    errormessage = sprintf('Error in degree2semitone: out of range degree "%d"\n', degree);
+    
+    if verbose == 1
+        fprintf(1,errormessage);
+    end
+end
+