christopherh@1: %
christopherh@1: % PARSEINTERVAL
christopherh@1: % 
christopherh@1: % [degree, accidentals, success, errormessage] = parseinterval(interval, {verbose})
christopherh@1: % 
christopherh@1: % Parse an interval to a degree value and a number of accidentals
christopherh@1: % if accidentals is positive it denotes number of sharps,
christopherh@1: % if it is negative it denotes number of flats.
christopherh@1: % If the omit interval character '*' is found then present is returned as 0 
christopherh@1: % otherwise it is 1. 
christopherh@1: %
christopherh@1: % Success = 1 if symbols parsed 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: % returns:  degree      (integer)
christopherh@1: %           accidentals (integer) 
christopherh@1: %           present     (boolean)
christopherh@1: %           success     (boolean)
christopherh@1: %           errormessage (string)  
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 [degree,accidentals,present,success, errormessage] = parseinterval(interval, verbose)
christopherh@1: 
christopherh@1: if nargin < 2
christopherh@1:     verbose = 0;
christopherh@1: end
christopherh@1: 
christopherh@1: ilength = length(interval);
christopherh@1: 
christopherh@1: errormessage = '';
christopherh@1: accidentals = 0;
christopherh@1: degree = 0;
christopherh@1: success=1;
christopherh@1: present = 1;
christopherh@1: 
christopherh@1: index = 1;
christopherh@1:  
christopherh@1: % if the input string is not empty   
christopherh@1: if (isempty(interval) == 0)
christopherh@1: 
christopherh@1:     
christopherh@1:     % check for omit interval '*'
christopherh@1:     if interval(index) == '*' 
christopherh@1:         present = 0;
christopherh@1:         index = index +1;
christopherh@1:     end
christopherh@1: 
christopherh@1: 
christopherh@1:     tempstring = '';
christopherh@1:     tempindex = 1;
christopherh@1:     % parse the interval string
christopherh@1:     while index <= ilength
christopherh@1: 
christopherh@1:         switch interval(index)
christopherh@1: 
christopherh@1:             case 'b' % FLAT
christopherh@1:                 accidentals = accidentals - 1; %decrement accidental count
christopherh@1:                 index = index + 1;
christopherh@1: 
christopherh@1:             case '#' % SHARP
christopherh@1:                 accidentals = accidentals + 1; %increment accidental count
christopherh@1:                 index = index + 1;
christopherh@1:              
christopherh@1:             case {'1','2','3','4','5','6','7','8','9'}
christopherh@1:                 % if neither of the above then remaining string should be
christopherh@1:                 % an integer degree value
christopherh@1:                 %tempstring(tempindex) = interval(index);
christopherh@1:                 
christopherh@1:                 %tempindex = tempindex+1;
christopherh@1:                 %index = index+1;
christopherh@1:                 success=1;
christopherh@1:                 break
christopherh@1:                 
christopherh@1:             otherwise
christopherh@1:                 % unrecognised symbol
christopherh@1:                 success=0;
christopherh@1:                 break; %index = ilength+1;
christopherh@1:         end
christopherh@1:     end
christopherh@1: else
christopherh@1:     success=0;
christopherh@1: end
christopherh@1: 
christopherh@1: if success
christopherh@1: 
christopherh@1: % convert the degree string to an integer
christopherh@1:     [degree, success] = str2num(interval(index:end)); 
christopherh@1: 
christopherh@1:     % check it worked and that the degree is valid
christopherh@1:     if isempty(degree) || (degree <= 0) 
christopherh@1:         success = 0; 
christopherh@1:     end
christopherh@1: end            
christopherh@1: 
christopherh@1: if(success==0) % correct interval therefore return success = 1 
christopherh@1:     % if not an integer then the interval string is incorrect
christopherh@1:     errormessage = sprintf(['Error in parseinterval: Unrecognised interval "' interval '"\n']);
christopherh@1:     degree = 0;
christopherh@1:     if verbose == 1
christopherh@1:         fprintf(1, errormessage);
christopherh@1:     end
christopherh@1:     
christopherh@1: end