title: can I use numerical features in crf model
body: <p>Is it possible/good to add numerical features in crf models? e.g. position in the sequence. </p>
  
  <p>I'm using <a href="http://www.chokkan.org/software/crfsuite/manual.html" rel="nofollow">CRFsuite</a>. It seems all the features will be converted to string, e.g. 'pos=0', 'pos=1', which then lose it's meaning as euclidean distance. </p>
  
  <p>Or should I use them to train another model, e.g. svm, then ensemble with crf models? </p>