wolffd@0: function varargout = mirkeystrength(orig,varargin)
wolffd@0: %   ks = mirkeystrength(x) computes the key strength, i.e., the probability
wolffd@0: %   	associated with each possible key candidate.
wolffd@0: %   Optional parameters:
wolffd@0: %       mirkeystrength(...,'Frame',l,h) orders a frame decomposition of window
wolffd@0: %           length l (in seconds) and hop factor h, expressed relatively to
wolffd@0: %           the window length. For instance h = 1 indicates no overlap.
wolffd@0: %           Default values: l = 1 seconds and h = .5
wolffd@0: %       The mirchromagram options 'Weight' and 'Triangle' can be specified.
wolffd@0: %   [ks,c] = mirkeystrength(...) also displays the chromagram used for the key 
wolffd@0: %       strength estimation.
wolffd@0: %
wolffd@0: % Krumhansl, Cognitive foundations of musical pitch. Oxford UP, 1990.
wolffd@0: % Gomez, Tonal description of polyphonic audio for music content processing,
wolffd@0: %   INFORMS Journal on Computing, 18-3, pp. 294-304, 2006.
wolffd@0: 
wolffd@0:         wth.key = 'Weight';
wolffd@0:         wth.type = 'Integer';
wolffd@0:         wth.default = .5;
wolffd@0:     option.wth = wth;
wolffd@0:     
wolffd@0:         tri.key = 'Triangle';
wolffd@0:         tri.type = 'Boolean';
wolffd@0:         tri.default = 0;
wolffd@0:     option.tri = tri;
wolffd@0: 
wolffd@0: specif.option = option;
wolffd@0: specif.defaultframelength = .1;
wolffd@0: specif.defaultframehop = .125;
wolffd@0: 
wolffd@0: varargout = mirfunction(@mirkeystrength,orig,varargin,nargout,specif,@init,@main);
wolffd@0: 
wolffd@0: 
wolffd@0: function [x type] = init(x,option)
wolffd@0: if not(isamir(x,'mirchromagram'))
wolffd@0:     x = mirchromagram(x,'Weight',option.wth,'Triangle',option.tri,'Normal');
wolffd@0: else
wolffd@0:     x = mirchromagram(x,'Wrap','Normal');
wolffd@0: end
wolffd@0: type = 'mirkeystrength';
wolffd@0: 
wolffd@0: 
wolffd@0: function k = main(orig,option,postoption)
wolffd@0: if iscell(orig)
wolffd@0:     orig = orig{1};
wolffd@0: end
wolffd@0: if isa(orig,'mirkeystrength')
wolffd@0:     c = [];
wolffd@0:     k = orig;
wolffd@0: else
wolffd@0:     c = orig;
wolffd@0:     load gomezprofs;
wolffd@0:     m = get(c,'Magnitude');
wolffd@0:     st = cell(1,length(m));
wolffd@0:     kk = cell(1,length(m));
wolffd@0:     %disp('Computing key strengths...')
wolffd@0:     for i = 1:length(m)
wolffd@0:         mi = m{i};
wolffd@0:         if not(iscell(mi))
wolffd@0:             mi = {mi};
wolffd@0:         end
wolffd@0:         si = cell(1,length(mi));
wolffd@0:         ki = cell(1,length(mi));
wolffd@0:         for j = 1:length(mi)
wolffd@0:             mj = mi{j};
wolffd@0:             sj = zeros(12,size(mj,2),size(mj,3),2);
wolffd@0:             for k = 1:size(mj,2)
wolffd@0:                 for l = 1:size(mj,3)
wolffd@0:                     tmp = corrcoef([mj(:,k,l) gomezprofs']);
wolffd@0:                     sj(:,k,l,1) = tmp(1,2:13);
wolffd@0:                     sj(:,k,l,2) = tmp(1,14:25);
wolffd@0:                     kj(:,k,l) = {'C','C#','D','D#','E','F','F#','G','G#','A','A#','B'};
wolffd@0:                 end
wolffd@0:             end
wolffd@0:             si{j} = sj;
wolffd@0:             ki{j} = kj;
wolffd@0:         end
wolffd@0:         st{i} = si;
wolffd@0:         kk{i} = ki;
wolffd@0:     end
wolffd@0:     k = class(struct,'mirkeystrength',mirdata(c));
wolffd@0:     k = purgedata(k);
wolffd@0:     k = set(k,'Title','Key strength','Abs','tonal center','Ord','strength',...
wolffd@0:               'Tonic',kk,'Strength',st,'MultiData',{'maj','min'},'Interpolable',0);
wolffd@0: end
wolffd@0: k = {k c};