new_contents: """Implementation of an alpha-beta filter"""
  import numpy as np
  
  
  def alpha_beta(data, x_0, dx, alpha, beta, dt=1.):
      """
      data: numpy.nd.array
          Dataset
      x_0: float
          Position of x at time 0
      dx: float
          Change in x
      alpha: [0,1]
          Preference to follow prediction
      beta: [0,1]
          Preference to follow measurement
      dt: float
          Change in time/step-size of time
      """
      x_k = x_0
      positions = []
      for x_meas in data:
          # Prediction
          x_pred = x_k + (dx*dt)
          # Update
          error = x_meas - x_pred
          dx = dx + (beta*(error))/dt
          x_k = x_pred + alpha * error
          positions.append(x_k)
      return np.array(positions)
  
subject: Add alpha-beta filter