Reputation: 21
I want to know how arima works well by using difference between predict value and real value. So I used predict()(the below one) but it is different from the value of plot_predict()(above one). (please look how it is different) enter image description here I think plot_predict values are what I want, since it is closer to the real values but what I can get from predict() is so low. Please help me to find the answer. Appreciate for your help.
For the first one, I used
from statsmodels.tsa.arima_model import ARIMA
model = ARIMA(sales, order=(0,1,1))
model_fit = model.fit(trend='nc',full_output=True, disp=1)
print(model_fit.summary())
model_fit.plot_predict(dynamic=False)
for the below one, I used
predict=model_fit.predict()
plt.plot(predict)
Upvotes: 2
Views: 2023
Reputation: 325
Which version of statsmodels
do you use?
I think you are using statsmodels
version 10.2 (which is currently a default version of statsmodels
in Google Colab)
Pay attention to the typ
parameter in the function (described in this link) and change the value into levels
to get the prediction value instead of differenced value.
predict=model_fit.predict(typ='levels')
plt.plot(predict)
plt.plot(sales)
Upvotes: 1