how to write Arima Equation using modeled output
I have a daily series from 3rd jan 2016  28 feb 2018
Below is the output of auto.arima
model < auto.arima(ts_268001_1,xreg=reg)
model
**Series: ts_268001_1
Regression with ARIMA(3,1,2)(1,0,0)[7] errors
Coefficients:
ar1 ar2 ar3 ma1 ma2 sar1 promo_1 promo_2 promo_3
0.4655 0.5651 0.2229 0.0372 0.8954 0.1261 14.2482 9.3060 4.6454
promo_4 promo_5 Xmas
10.9198 6.3006 31.8271
s.e.
0.0496 0.0485 0.0417 0.0332 0.0308 0.0424 2.4490 2.7639 3.8073
s.e. 1.5005 0.8855 3.5790
sigma^2 estimated as 32.87:
log likelihood=2257.83
AIC=4541.66
AICc=4542.18
BIC=4601.1**
How to write the the equation so that I can directly use the equation to calculate the values.?
What is this "sar1"?
Where is my intercept?
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