nl_tokens: for explanations
pl_tokens: function WinnowHash ( opts ) { if ( ! opts ) opts = { } this . debug = opts . debug || false ; // Default values are based on Carvalho and Cohen, 2006, section 4.2:	 this . default_positive_weight = opts . default_positive_weight || 2.0 ; this . default_negative_weight = opts . default_negative_weight || 1.0 ; this . do_averaging = opts . do_averaging || false ; this . threshold = ( 'threshold' in opts ? opts . threshold : 1 ) ; this . promotion = opts . promotion || 1.5 ; this . demotion = opts . demotion || 0.5 ; this . margin = ( 'margin' in opts ? opts . margin : 1.0 ) ; this . retrain_count = opts . retrain_count || 0 ; this . detailed_explanations = opts . detailed_explanations || false ; this . bias = ( 'bias' <mask> opts ? opts . bias : 1.0 ) ; this . positive_weights = { } ; this . negative_weights = { } ; this . positive_weights_sum = { } ; // for averaging; count only weight vectors with successful predictions (Carvalho and Cohen, 2006). this . negative_weights_sum = { } ; // for averaging; count only weight vectors with successful predictions (Carvalho and Cohen, 2006). }