title: How to label the training projections obtained by PCA to use for training SVM for classification? MATLAB
body: <p>I have a "training set" of images. I have formed the 'Eigenspace'. Now i need to label the projections to train the SVM. The projections of "face 1" to the Eigenspace has to be labelled +1 and the projections of all the other faces to the Eigenspace has to be labelled -1. </p>
  
  <p>I don't know how to do this.Any suggestions would be really helpful!</p>
  
  <p>I formed the eigenspace using the following : </p>
  
  <pre><code>    function [signals,V] = pca2(data)
      [M,N] = size(data); 
      data = reshape(data, M*N,1); % subtract off the mean for each dimension 
      mn = mean(data,2); 
      data = bsxfun(@minus, data, mean(data,1)); 
      % construct the matrix Y 
      Y = data'*data / (M*N-1); 
      [V D] = eigs(Y, 10); % reduce to 10 dimension 
      % project the original data 
      signals = data * V; 
  </code></pre>