title: ARIMA Forecast: Cannot cast ufunc subtract output from dtype('float64') to dtype('int64') with casting rule 'same_kind'
body: <p>I am using ARIMA to fit values and save it as a pickle file. Post that, the pickle file is used to get out of sample predictions. However, while getting sample predictions I am getting the following error:
  Cannot cast ufunc subtract output from dtype('float64') to dtype('int64') with casting rule 'same_kind'.</p>
  
  <pre><code>def forecast_fit(df):            
    series=df
    X = series.values
    train=X
    model = ARIMA(X, order=(1,0,1))
    model_fit = model.fit(disp=0)
    model_fit.save('model.pkl')
  forecast_fit(df)
  #Out of sample forecasts
  loaded = ARIMAResults.load('model.pkl)
  forecast = loaded.forecast(steps=17)[0]        #error_occurs_here
  df=pd.DataFrame(forecast, columns=[i+'_hat'])  
  </code></pre>
  
  <p>The df contains the following data:
  <a href="https://docs.google.com/spreadsheets/d/14W77ra-nQYqvDN8wSPhhiN11lBnob6ZW0UVevQ5orKk/edit?usp=sharing" rel="noreferrer">https://docs.google.com/spreadsheets/d/14W77ra-nQYqvDN8wSPhhiN11lBnob6ZW0UVevQ5orKk/edit?usp=sharing</a></p>
  
  <p>I am attaching the data because the error occurs with this very sample, rest of the variables(I am repeating the exercise for many other variables) don't produce the error. </p>