Hi Community,
I am new to R. Based on study, I have tried forecasting. I have data for three years month wise (201701-201912). I want to forecast for next 12 months(202001-202012). Here Jan 2020 forecast value must be based on same periods in the history(201701,201801,201701). Feb 2020 forecast value must be based on 201702,201802,209102.
Here is my raw data.
Here is my R-Script using ARIMA Forecast
library(forecast)
library(tseries)
library(gridExtra)
ARIMA_Sales<-ts(dataset$Final1,start=2017,frequency = 12)
Sales_Forecast<-arima(ARIMA_Sales,order=c(1,0,1),seasonal=c(0,1,0))
Predicted_Sales<- forecast(Sales_Forecast, h=12, level = 0.40)
Predictedsale <- print (Predicted_Sales)
grid.table(Predictedsale)
Output:
Jan 2020 - 13368.11
Feb 2020 - -40.97
Mar 2020 - 12204.87
Apr 2020 - 19977.45
May 2020 - 21150.34
Jun 2020 - 9767.14
July 2020 - 4635.53
August 2020 - 11969.47
Sept 2020 - 22143.42
Oct 2020 - -23.22
Nov 2020 - 8029.16
Dec 2020 - 28211.31
Analysis:
For Feb 2020, my forecasted value is -40.97.
Past Values:
201702 - 94
201802 - 120
201902 - 220
Doubt: From 2017 to 2019, the value is increasing. But my forecast value is decreasing. Please assist me in where I am wrong.