Research Article

Position-Based Feature Selection for Body Sensors regarding Daily Living Activity Recognition

Algorithm 1

for i = 1 : 3 % We run three feature selection algorithms
   CVO = LeaveOneOutCV ( ); %Leave-one-out cross-validation
   for j = 1:CVO. NumofTestSets
      % Get training and test sets
      X_train = Features {i} (training Index,:);
      Y_train = Activities (training Index);
      X_test = Features {i} (testIndex,:);
      Y_test = Activities (testIndex);
      k_idex = 0;
      for k = 1:CVO. MaxNumOfFeature (i)
         k_idx = k_idex + 1;
         % Get features according to rank of feature
         fs_index = FeatureRanking {i} (1 : k);
         % Evaluate the feature importance by K-NN algorithm.
         Prediction = knnModel (X_train (:, fs_index), ….
              Y_train, X_test (:, fs_index), 1);
         cvAccuracy (j, k_idx) = sum (double (Prediction == Y_test)) ….
                           /TestSize (j);
      end
  end
Accuracy {1,i} (1: size (cvAccuracy, 2)) = mean (cvAccuracy);
end