Additive&Multiplicative

library(readxl)
crudeoil <- read_excel("Desktop/BC 22Spr/crudeoil.xlsx")
View(crudeoil)

library(dplyr)

## Warning: package 'dplyr' was built under R version 4.1.2

## 
## Attaching package: 'dplyr'

## The following objects are masked from 'package:stats':
## 
##     filter, lag

## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union

library(tsibble)

## 
## Attaching package: 'tsibble'

## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, union

library(ggplot2)
library(forecast)

## Registered S3 method overwritten by 'quantmod':
##   method            from
##   as.zoo.data.frame zoo

library(seasonal)

crudeoil<-ts(crudeoil,frequency=12,start=c(2009,1))
crudeoil

##         Jan    Feb    Mar    Apr    May    Jun    Jul    Aug    Sep    Oct
## 2009 317275 262339 303897 285934 281147 284093 287569 279111 289561 272678
## 2010 274568 253150 299033 302836 310396 310153 318991 309053 284192 272415
## 2011 296158 235122 292010 265822 289106 285572 295338 287633 273698 284594
## 2012 257536 242560 271697 258417 272766 270684 266782 263945 250160 250303
## 2013 245715 203162 231414 231621 238809 231912 245724 251079 237699 230822
## 2014 234969 201572 225487 226639 222177 212025 236534 231649 224851 221600
## 2015 222315 198807 235360 216229 224604 219618 228160 239212 216838 220171
## 2016 236065 229492 248383 228344 245749 226802 250986 248482 241213 234666
## 2017 262811 220558 253114 246132 264554 242677 245369 245611 219708 238109
## 2018 248552 209942 236216 247608 242857 254283 246671 247656 227795 227975
## 2019 234307 178257 210276 209958 221259 214563 215083 215273 194485 193493
## 2020 198663 189060 195181 165586 188693 191919 183087 168406 161926 164494
## 2021 181197                                                               
##         Nov    Dec
## 2009 273248 265615
## 2010 271185 279096
## 2011 268189 279359
## 2012 244987 235120
## 2013 222248 240519
## 2014 218845 223978
## 2015 221130 244965
## 2016 240691 242213
## 2017 230230 241245
## 2018 226251 219240
## 2019 174531 211837
## 2020 168655 178597
## 2021

plot.ts(crudeoil)

plot(decompose(crudeoil,type=("additive")))

plot(decompose(crudeoil,type=("multiplicative")))