title: How to fix pmdarima straight line predictions
body: <p>I'm trying to forecast the out of sample using pmdarima. However All it produces is a straight line prediction.</p>
  
  <p>The original data_set
  <a href="https://i.imgur.com/ONeiFI2.png" rel="nofollow noreferrer">training and validation set</a></p>
  
  <p>And the predictions:
  <a href="https://i.imgur.com/54Eowjd.png" rel="nofollow noreferrer">training and validation set</a>
  (its a very faint orange line after 2019)</p>
  
  <p>The code for the model:</p>
  
  <pre><code>#building the model
  from pmdarima.arima import auto_arima
  model = auto_arima(train, trace=True, error_action='ignore', suppress_warnings=True)
  model.fit(train)
  </code></pre>
  
  <p>The fit result</p>
  
  <pre><code>ARIMA(callback=None, disp=0, maxiter=None, method=None, order=(3, 1, 4),
        out_of_sample_size=0, scoring='mse', scoring_args={},
        seasonal_order=(0, 0, 0, 1), solver='lbfgs', start_params=None,
        suppress_warnings=True, transparams=True, trend=None,
        with_intercept=True)
  </code></pre>
  
  <p>I expect predictions to at least be anything but straight lines.</p>