Mauch MIREX 2010

%

%NOTE2PITCHCLASS convert a note to a pitchclass value w.r.t middle C

% 

% [pitchclass, success, errormessage] = note2pitchclass(note, {verbose})

% 

% Converts a note string to a pitch class (integer) with C as reference 

% pitch class 0

% 

% Success = 1 if symbols parsed correctly, 0 otherwise.

%

% If optional argument 'verbose' is 1, function prints any errormessage to 

% the screen.

% 

% returns:  pitchclass (integer)

%           success (boolean)

%           errormessage (string)

%

%

% Author: Christopher Harte,  August 2005

% 

% Copyright: Centre for Digital Music, Queen Mary University of London 2005 

%

% This file is part of the C4DM Chord Toolkit.  

%

% 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 [pitchclass, success, errormessage] = note2pitchclass(note, verbose)

if nargin < 2

    verbose = 0;

end

errormessage = '';

ilength = length(note);

index = 1;

success = 1;

% first char should be a natural name A-G

switch note(index)

    case 'C' % natural C

            pitchclass = 0; 

            index = index + 1;

    case 'D' % natural D

            pitchclass = 2; 

            index = index + 1;

    case 'E' % natural E

            pitchclass = 4; 

            index = index + 1;

    case 'F' % natural F

            pitchclass = 5; 

            index = index + 1;

    case 'G' % natural G

            pitchclass = 7; 

            index = index + 1;

    case 'A' % natural A

            pitchclass = 9; 

            index = index + 1;

    case 'B' % natural B

            pitchclass = 11; 

            index = index + 1;

    otherwise %Unrecognised character

            errormessage = sprintf(['Error in Note2PitchClass: Unrecognised note "' note '"\n']);

            index = ilength + 1;

            pitchclass=-1;

            success = 0;

end

% any other characters should be either flats or sharps

while index <= ilength

    switch(note(index))

        case 'b' % FLAT

            pitchclass = pitchclass - 1; %decrement pitchclass value

            index = index + 1;

        case '#' % SHARP

            pitchclass = pitchclass + 1; %increment pitchclass value

            index = index + 1;

        otherwise % Unrecognised character

            errormessage = sprintf(['Error in Note2PitchClass: Unrecognised note "' note '"\n']);

            index = ilength + 1;

            pitchclass=-1;

            success = 0;

    end        

end

% Use modulo command to make sure that we are back within range 0-12

if(success == 1)

    pitchclass = mod(pitchclass,12);

else

   if(verbose == 1)

      fprintf(1,errormessage); 

   end

end