code: def closenessScores(self, expValues, actValues, fractional=True):
      
  
      expValue = expValues[0]
      actValue = actValues[0]
      if self.periodic:
        expValue = expValue % self.maxval
        actValue = actValue % self.maxval
  
      err = abs(expValue - actValue)
      if self.periodic:
        err = min(err, self.maxval - err)
      if fractional:
        pctErr = float(err) / (self.maxval - self.minval)
        pctErr = min(1.0, pctErr)
        closeness = 1.0 - pctErr
      else:
        closeness = err
  
      return numpy.array([closeness])
docs: See the function description in base.py