nl_tokens: Adds the given value to the dataset .
pl_tokens: public void add ( double value ) { if ( count == 0 ) { count = 1 ; mean = value ; <mask> = value ; max = value ; if ( ! isFinite ( value ) ) { sumOfSquaresOfDeltas = NaN ; } } else { count ++ ; if ( isFinite ( value ) && isFinite ( mean ) ) { // Art of Computer Programming vol. 2, Knuth, 4.2.2, (15) and (16) double delta = value - mean ; mean += delta / count ; sumOfSquaresOfDeltas += delta * ( value - mean ) ; } else { mean = calculateNewMeanNonFinite ( mean , value ) ; sumOfSquaresOfDeltas = NaN ; } min = Math . min ( min , value ) ; max = Math . max ( max , value ) ; } }