code: def predict(self, x):
          
          y = np.dot(self.w, x)
          return y
docs: This function calculates the new output value `y` from input array `x`.
  
          **Args:**
  
          * `x` : input vector (1 dimension array) in length of filter.
  
          **Returns:**
  
          * `y` : output value (float) calculated from input array.