Chris@0: function f_featureNorm = normalizeFeature(f_feature,normP, threshold)
Chris@0: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Chris@0: % Name: normalizeFeature
Chris@0: % Date of Revision: 2011-03
Chris@0: % Programmer: Meinard Mueller, Sebastian Ewert
Chris@0: %
Chris@0: % Description:
Chris@0: % - Normalizes a feature sequence according to the l^p norm
Chris@0: % - If the norm falls below threshold for a feature vector, then the
Chris@0: % normalized feature vector is set to be the unit vector.
Chris@0: %
Chris@0: % Input:
Chris@0: %         f_feature
Chris@0: %         normP
Chris@0: %         threshold
Chris@0: %
Chris@0: % Output:
Chris@0: %         f_featureNorm
Chris@0: %
Chris@0: % License:
Chris@0: %     This file is part of 'Chroma Toolbox'.
Chris@0: % 
Chris@0: %     'Chroma Toolbox' is free software: you can redistribute it and/or modify
Chris@0: %     it under the terms of the GNU General Public License as published by
Chris@0: %     the Free Software Foundation, either version 2 of the License, or
Chris@0: %     (at your option) any later version.
Chris@0: % 
Chris@0: %     'Chroma Toolbox' is distributed in the hope that it will be useful,
Chris@0: %     but WITHOUT ANY WARRANTY; without even the implied warranty of
Chris@0: %     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
Chris@0: %     GNU General Public License for more details.
Chris@0: % 
Chris@0: %     You should have received a copy of the GNU General Public License
Chris@0: %     along with 'Chroma Toolbox'. If not, see <http://www.gnu.org/licenses/>.
Chris@0: % 
Chris@0: %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Chris@0: 
Chris@0: f_featureNorm = zeros(size(f_feature));
Chris@0: 
Chris@0: % normalise the vectors according to the l^p norm
Chris@0: unit_vec = ones(1,12);
Chris@0: unit_vec = unit_vec/norm(unit_vec,normP);
Chris@0: for k=1:size(f_feature,2);
Chris@0:     n = norm(f_feature(:,k),normP);
Chris@0:     if n < threshold
Chris@0:         f_featureNorm(:,k) = unit_vec;
Chris@0:     else
Chris@0:         f_featureNorm(:,k) = f_feature(:,k)/n;
Chris@0:     end
Chris@0: end
Chris@0: 
Chris@0: end