1. MA(2)

Membangiktkan model MA(2) dengan teta1 = 0.4 dan teta2 = 0.6 sebanyak 300 data (manual dan sengan arima.sim)

White Noise

wn <- rnorm(300)
ts.plot(wn)

Akan dicoba membangkitkan proses MA paling sederhana, yaitu MA(1) dengan \(\theta = 0.4\) dan \(\theta = 0.6\) sebanyak 300 observasi dan \(c=0\). Karena diperlukan satu nilai awal untuk \(e_{t-1}\) dan \(e_{t-2}\), masukkan nilai pertama white noise sebagai nilai awal tersebut.

set.seed(023)
ma <- wn[c(1,2)]
ma
## [1] 0.3764867 2.8910833

Nilai-nilai selanjutnya dapat dicari melalui loop. Bentuk loop dapat dilihat dari rumus MA(2) yang hendak dibangkitkan:

\[ y_t = e_t+0.4e_{t-1}+0.6e_{t-2} \]

for(i in 3:300){
   ma[i] <- wn[i] + 0.4 * wn[i-1] + 0.6 * wn[i - 2] 
}
ma
##   [1]  0.376486659  2.891083265  1.272939391  1.049329503  0.528455337
##   [6] -0.660323932 -0.867766297 -1.167038680 -1.276285900 -0.756024562
##  [11]  0.102562145 -1.673677061 -0.414898173 -2.635847349  0.643421450
##  [16] -2.470738795  0.807116406 -2.435734193  0.789594500 -1.211021488
##  [21]  0.309792804 -2.591360944 -1.551970879 -1.163496898  0.355554852
##  [26]  0.035818895  0.190514914 -0.481533808  0.335096222  0.439786757
##  [31] -0.586768006 -0.180757528  0.476906074  1.377054627  0.453350539
##  [36]  1.089294028 -1.102237824  0.290631381 -1.579802794 -0.654088463
##  [41] -1.806967638 -1.015694637 -2.271583889 -1.296964313 -1.282248111
##  [46] -3.416281679 -1.394294840 -2.096391138 -0.385318133  0.433415090
##  [51] -0.571718551 -0.781329468 -2.274489251 -2.495999349 -2.896649704
##  [56] -1.507575269  0.167025748 -1.362883701 -1.163388675 -0.453860137
##  [61] -0.082191647  2.081975145 -0.731771731  0.447599146 -0.949067464
##  [66] -0.981865970 -1.253537117 -0.652734853  0.230514709  0.508389876
##  [71] -0.335137033 -0.577333952  1.125884853  1.884175410  1.868599712
##  [76] -0.373986078  0.540078189  0.326100544  0.922779061 -0.676952910
##  [81] -1.021652887 -2.455669492 -0.525253954 -0.756449866  0.242026733
##  [86] -0.793622237 -2.118250559 -1.171944294 -1.254756058  0.156409896
##  [91]  0.881224244  1.963714779  1.319895662 -0.541030517  0.372948487
##  [96] -1.269736070  1.185564889 -0.749225458  1.348942202  0.610003501
## [101]  1.471093899  1.131809788 -0.449774717  0.528073425 -1.069169086
## [106]  0.655515959  0.813411637  1.980547838  0.292419372  2.056655613
## [111]  1.452182364  1.443411029  1.538886178 -0.586702602 -0.802033556
## [116] -1.632108730  0.130561699 -0.916958534  1.760703550  1.559644810
## [121]  1.713929615  1.637894941  0.880972909  1.384500177  2.096981934
## [126]  0.884207740 -0.279617376  0.291208970 -0.768094492 -1.086892414
## [131] -0.560696861  0.318145290  0.006487837 -0.294477306 -2.566374703
## [136] -1.711312552 -1.945850023  1.209309432  0.787209035  1.817054541
## [141]  0.042340797  0.371645997 -1.666279378 -0.450065553 -1.926881708
## [146]  0.845610896  0.317984728  2.453425058  0.616148527 -1.080111772
## [151] -0.732158983 -2.282823453 -0.856121205 -0.284745928 -2.527788313
## [156] -1.583975853 -0.262485375  0.350113476  2.062510435  1.118959736
## [161]  0.810890964  0.361658001 -0.762405075  0.174734931 -1.333189977
## [166] -1.444625441 -2.294630100 -2.423037666  0.913607099  1.283219664
## [171]  2.669925684  2.144997162  1.016223907  2.781621020  2.229933096
## [176]  1.563078926  2.121133394 -0.124324765  0.666300793 -1.560166674
## [181] -1.736651137 -3.875143179 -3.522676167 -2.360833581 -1.000336996
## [186] -0.843211137 -0.135650765 -0.709671480  1.390898586 -0.096231517
## [191]  0.739315875  0.951040561  0.324689822  0.833814176  1.129219631
## [196]  1.207678300 -1.383559378 -0.683797515  0.092205088  0.132851910
## [201] -0.348714809 -0.020167567 -1.108436389 -2.394337109 -0.581490203
## [206] -2.833926427 -1.884126069  0.288866728  0.292297373  0.451081021
## [211] -0.030659568  0.245960795  1.332739654  0.941277885  1.933980662
## [216]  0.055740608  0.995855870  1.134146672  1.705224826  1.257882265
## [221]  0.688890766  0.979865547  0.082975177  0.745006291  0.426795522
## [226]  1.023379835  0.122487130 -0.648209322 -3.208880364 -0.473769727
## [231] -0.133838137  1.866038951  1.498457094 -0.849790736 -0.178248189
## [236] -1.921776375 -0.629875868 -1.580832048  0.598432589 -0.159793430
## [241]  0.880989211  0.987022925  0.514417044  0.074549124  0.662336368
## [246] -1.918440785 -0.045150758 -0.469879540  0.811847904  0.304228772
## [251] -0.298448803 -1.353749214 -1.554844881 -0.290228437 -1.934766491
## [256] -0.092434755 -3.369647389 -2.324057797 -1.958702604 -0.530963197
## [261] -0.908340921  0.324453692 -1.154031550 -1.415538487 -0.882397739
## [266] -0.111151421 -0.652326891  0.270556538 -0.805420362  0.272980086
## [271] -0.057273789  0.859319788 -1.786286310 -2.927631672 -2.497477692
## [276] -0.851240606  0.312379603 -0.187899331 -0.890509851 -1.178938323
## [281]  0.274957064 -1.013144834 -0.549619209 -0.103440636 -0.030645415
## [286]  1.420424337 -0.710422968  1.709037642 -1.476237380  1.602330567
## [291] -2.399768731  0.667900943 -1.152654377  0.723381614 -0.155364848
## [296]  1.416746072  0.894366166  1.313866117 -2.067594319 -1.228167575

Selain menggunakan cara di atas, pembangkitan proses MA(1) dapat dilakukan dengan fungsi arima.sim() sebagai berikut.

ma1 <- arima.sim(list(order=c(0,0,2), ma=c(0.4,0.6)), n=300)
ma1
## Time Series:
## Start = 1 
## End = 300 
## Frequency = 1 
##   [1]  0.85532165  1.89788567  2.26192060  2.58216539  0.76287298  1.57246527
##   [7]  0.28626760  2.20547776  0.87586260 -0.01375221 -0.57632971 -0.26184638
##  [13] -1.19696950  0.11051650 -1.12674941 -0.46550299 -1.08834532  0.78946442
##  [19]  0.99363469  0.54488810  1.06324806 -1.19017065 -0.52414013 -0.91294433
##  [25] -0.83147786  1.03720732 -0.47097327  0.64811158 -0.88290527 -0.02312615
##  [31] -1.43931644 -1.64968475 -1.39008210 -0.65330070  1.25738044 -0.71337628
##  [37]  1.10849727 -0.22845302  1.65205692  1.88572609  2.10295151  0.19021663
##  [43] -1.04254226 -2.70692797 -1.28888624 -0.96271449  0.56002069 -0.03743293
##  [49]  1.47778120  0.12843854 -1.33627732 -0.24111047  0.30256183  0.05804925
##  [55] -0.17148592 -0.45876310  0.74344799  1.50725901  0.56653033  0.41060169
##  [61] -0.60597480 -0.10819194  1.62656718 -0.34906235 -0.31414295 -2.38467610
##  [67] -0.36860151 -1.71455673  0.68886005 -0.86754890  0.13105888  0.72051062
##  [73]  0.34002427  1.05509506  1.46491577 -1.64327112 -1.56753551 -2.47941910
##  [79] -1.00433731  0.34550952  2.23416907  1.62923000  1.89627742 -1.56284182
##  [85] -1.05529717 -2.02971830 -0.03406615 -0.27606109  1.80692276  1.70825979
##  [91]  2.03699812  0.91170001 -0.06978773 -0.48516206  0.96619763  1.41314467
##  [97]  1.97170910  1.50566833  1.04656140  1.42455384 -1.31470295 -0.15186704
## [103] -1.97176732 -0.67637421 -0.03167275  1.24923636 -1.37686269 -0.53243299
## [109] -1.57842549  1.08593208  2.17861716  2.13231699  1.64243148  0.22780396
## [115]  0.61092860 -0.88031633  0.14395071 -0.61974842 -1.17642515 -0.10902232
## [121] -0.58641830  0.05007131 -0.18167803 -1.29156689  1.68421564  0.22127221
## [127]  2.57116670  0.77449608  0.64684226  0.76842793  0.85890976 -0.25045341
## [133]  0.23407008  1.03166739  1.58558709  2.25104336 -1.56171520 -0.02213279
## [139] -0.91793337  1.32826007  0.88368762  1.43162530 -0.03439972  0.85605287
## [145] -0.29619502 -0.06515819 -1.12612274  0.95605918  1.35617739 -0.49863601
## [151] -0.81676837 -1.55758667  0.84907280  0.45287783 -0.12942991 -1.20114491
## [157] -3.29270192 -2.60482178 -2.60256467 -0.75556226 -1.43112671 -0.62130758
## [163] -0.06842639 -0.49351716  0.57141593 -0.89025605 -1.03204385 -1.20550630
## [169] -0.42569403 -1.27846186  0.14922865 -0.18388690  0.74158243  1.42967028
## [175]  0.70443578 -0.08261893 -0.66704427 -1.05893039 -1.41836248 -0.46432900
## [181] -0.29077092  0.42001813 -0.37550346  0.41111787 -0.10353333  1.71914871
## [187]  1.19777894  1.83449219 -0.74629489 -0.38710060  0.25720932 -0.34645704
## [193] -0.83306803 -0.42488436 -0.22880897  1.39802605  0.92000511 -0.76108532
## [199]  0.15447525 -2.89475132 -0.27701271 -0.68046076 -0.80148048 -0.16818554
## [205] -1.66924564 -0.79161896 -0.67295144 -0.37517414 -1.21735154  0.71308912
## [211] -0.62629048  0.16177483 -1.01314833  1.86629099 -0.38665491 -1.11289058
## [217] -1.76804712 -0.85877929 -0.24114300 -0.87086115 -2.49710754  0.04395285
## [223] -2.06543104 -0.24829907 -2.29193295  0.44615300  0.90533735  1.11020221
## [229]  0.93515351  0.04319453 -0.23340236  0.47901747  0.51488742  2.23274873
## [235]  1.28058420  2.57857296  0.38363226  0.36200755  0.12247535  0.38890149
## [241] -0.63584754 -0.06824732  0.15789941 -1.51064529 -0.56218556 -1.45000740
## [247] -1.28285092 -2.08369824 -0.48923616 -0.88959105  1.55212468 -0.47454819
## [253]  0.50064531 -0.57093744  1.39375016  0.22705038 -0.63103283 -1.50621237
## [259] -0.06023872  1.24129841  0.35066690  0.92613290  0.07356613 -0.58473557
## [265]  0.05487049 -2.39064625  0.37471455  1.50795275  0.79290943  1.47272342
## [271] -1.31279017 -0.60240804 -2.20975460 -0.50230713 -1.46652374  1.55308133
## [277] -0.67004161 -0.02049327 -0.09207832 -1.06134338  0.47711417  0.36473761
## [283]  0.45959761  0.47837574  0.50438837  0.25779129  0.20091368 -0.20691914
## [289]  0.54826422 -1.53089719  1.40360454 -0.27107495 -0.03246342 -1.41807822
## [295] -0.59876274 -1.33165255  0.34882268  2.01456340  0.58235213  2.48521968

Buat plot time series, plot ACF, plot PACF, dan plot EACF. Identifikasi apakah data tersebut stasioner

Plot Time Series

ts.plot(ma)

Berdasarkan plot time series, terlihat bahwa data MA(2) yang dibangkitkan stasioner dalam rataan

Plot ACF

acf(ma,lag.max = 20)

Berdasarkan plot AFC tersebut, terlihat bahwa plot ACF cuts off di lag pertama dan kedua

Plot PACF

pacf(ma)

Berdasarkan plot PACF tersebut, terlihat bahwa plot PACF cenderung tails off dan membentuk gelombang sinus

Plot EACF

TSA::eacf(ma)
## AR/MA
##   0 1 2 3 4 5 6 7 8 9 10 11 12 13
## 0 x x o o o o o o o o o  o  o  o 
## 1 x x x o o o o o o o o  o  o  o 
## 2 x x o o o o o o o o o  o  o  o 
## 3 x x o o o o o o o o o  o  o  o 
## 4 x x o o o x o o o o o  o  o  o 
## 5 x x x o o o o o o o o  o  o  o 
## 6 x x x o x o o o o o o  o  o  o 
## 7 x x o x x o o o o o o  o  o  o

Berdasarkan pola segitiga nol pada plot EACF, terlihat bahwa segitiga nol berada pada ordo AR(0) dan ordo MA(3)

Dapat disimpulkan bahwa data tersebut stasioner

Buat scatterplot dan korelasi antara \(Y_t\) dengan \(Y_{t-1}\), \(Y_t\) dengan \(Y_{t-2}\), serta \(Y_t\) dengan \(Y_{t-3}\)

Korelasi antara \(Y_t\) dengan \(Y_{t-1}\)

#Yt
yt_ma <- ma[-1]
yt_ma
##   [1]  2.891083265  1.272939391  1.049329503  0.528455337 -0.660323932
##   [6] -0.867766297 -1.167038680 -1.276285900 -0.756024562  0.102562145
##  [11] -1.673677061 -0.414898173 -2.635847349  0.643421450 -2.470738795
##  [16]  0.807116406 -2.435734193  0.789594500 -1.211021488  0.309792804
##  [21] -2.591360944 -1.551970879 -1.163496898  0.355554852  0.035818895
##  [26]  0.190514914 -0.481533808  0.335096222  0.439786757 -0.586768006
##  [31] -0.180757528  0.476906074  1.377054627  0.453350539  1.089294028
##  [36] -1.102237824  0.290631381 -1.579802794 -0.654088463 -1.806967638
##  [41] -1.015694637 -2.271583889 -1.296964313 -1.282248111 -3.416281679
##  [46] -1.394294840 -2.096391138 -0.385318133  0.433415090 -0.571718551
##  [51] -0.781329468 -2.274489251 -2.495999349 -2.896649704 -1.507575269
##  [56]  0.167025748 -1.362883701 -1.163388675 -0.453860137 -0.082191647
##  [61]  2.081975145 -0.731771731  0.447599146 -0.949067464 -0.981865970
##  [66] -1.253537117 -0.652734853  0.230514709  0.508389876 -0.335137033
##  [71] -0.577333952  1.125884853  1.884175410  1.868599712 -0.373986078
##  [76]  0.540078189  0.326100544  0.922779061 -0.676952910 -1.021652887
##  [81] -2.455669492 -0.525253954 -0.756449866  0.242026733 -0.793622237
##  [86] -2.118250559 -1.171944294 -1.254756058  0.156409896  0.881224244
##  [91]  1.963714779  1.319895662 -0.541030517  0.372948487 -1.269736070
##  [96]  1.185564889 -0.749225458  1.348942202  0.610003501  1.471093899
## [101]  1.131809788 -0.449774717  0.528073425 -1.069169086  0.655515959
## [106]  0.813411637  1.980547838  0.292419372  2.056655613  1.452182364
## [111]  1.443411029  1.538886178 -0.586702602 -0.802033556 -1.632108730
## [116]  0.130561699 -0.916958534  1.760703550  1.559644810  1.713929615
## [121]  1.637894941  0.880972909  1.384500177  2.096981934  0.884207740
## [126] -0.279617376  0.291208970 -0.768094492 -1.086892414 -0.560696861
## [131]  0.318145290  0.006487837 -0.294477306 -2.566374703 -1.711312552
## [136] -1.945850023  1.209309432  0.787209035  1.817054541  0.042340797
## [141]  0.371645997 -1.666279378 -0.450065553 -1.926881708  0.845610896
## [146]  0.317984728  2.453425058  0.616148527 -1.080111772 -0.732158983
## [151] -2.282823453 -0.856121205 -0.284745928 -2.527788313 -1.583975853
## [156] -0.262485375  0.350113476  2.062510435  1.118959736  0.810890964
## [161]  0.361658001 -0.762405075  0.174734931 -1.333189977 -1.444625441
## [166] -2.294630100 -2.423037666  0.913607099  1.283219664  2.669925684
## [171]  2.144997162  1.016223907  2.781621020  2.229933096  1.563078926
## [176]  2.121133394 -0.124324765  0.666300793 -1.560166674 -1.736651137
## [181] -3.875143179 -3.522676167 -2.360833581 -1.000336996 -0.843211137
## [186] -0.135650765 -0.709671480  1.390898586 -0.096231517  0.739315875
## [191]  0.951040561  0.324689822  0.833814176  1.129219631  1.207678300
## [196] -1.383559378 -0.683797515  0.092205088  0.132851910 -0.348714809
## [201] -0.020167567 -1.108436389 -2.394337109 -0.581490203 -2.833926427
## [206] -1.884126069  0.288866728  0.292297373  0.451081021 -0.030659568
## [211]  0.245960795  1.332739654  0.941277885  1.933980662  0.055740608
## [216]  0.995855870  1.134146672  1.705224826  1.257882265  0.688890766
## [221]  0.979865547  0.082975177  0.745006291  0.426795522  1.023379835
## [226]  0.122487130 -0.648209322 -3.208880364 -0.473769727 -0.133838137
## [231]  1.866038951  1.498457094 -0.849790736 -0.178248189 -1.921776375
## [236] -0.629875868 -1.580832048  0.598432589 -0.159793430  0.880989211
## [241]  0.987022925  0.514417044  0.074549124  0.662336368 -1.918440785
## [246] -0.045150758 -0.469879540  0.811847904  0.304228772 -0.298448803
## [251] -1.353749214 -1.554844881 -0.290228437 -1.934766491 -0.092434755
## [256] -3.369647389 -2.324057797 -1.958702604 -0.530963197 -0.908340921
## [261]  0.324453692 -1.154031550 -1.415538487 -0.882397739 -0.111151421
## [266] -0.652326891  0.270556538 -0.805420362  0.272980086 -0.057273789
## [271]  0.859319788 -1.786286310 -2.927631672 -2.497477692 -0.851240606
## [276]  0.312379603 -0.187899331 -0.890509851 -1.178938323  0.274957064
## [281] -1.013144834 -0.549619209 -0.103440636 -0.030645415  1.420424337
## [286] -0.710422968  1.709037642 -1.476237380  1.602330567 -2.399768731
## [291]  0.667900943 -1.152654377  0.723381614 -0.155364848  1.416746072
## [296]  0.894366166  1.313866117 -2.067594319 -1.228167575
#Yt-1
yt_1_ma <- ma[-300]
yt_1_ma
##   [1]  0.376486659  2.891083265  1.272939391  1.049329503  0.528455337
##   [6] -0.660323932 -0.867766297 -1.167038680 -1.276285900 -0.756024562
##  [11]  0.102562145 -1.673677061 -0.414898173 -2.635847349  0.643421450
##  [16] -2.470738795  0.807116406 -2.435734193  0.789594500 -1.211021488
##  [21]  0.309792804 -2.591360944 -1.551970879 -1.163496898  0.355554852
##  [26]  0.035818895  0.190514914 -0.481533808  0.335096222  0.439786757
##  [31] -0.586768006 -0.180757528  0.476906074  1.377054627  0.453350539
##  [36]  1.089294028 -1.102237824  0.290631381 -1.579802794 -0.654088463
##  [41] -1.806967638 -1.015694637 -2.271583889 -1.296964313 -1.282248111
##  [46] -3.416281679 -1.394294840 -2.096391138 -0.385318133  0.433415090
##  [51] -0.571718551 -0.781329468 -2.274489251 -2.495999349 -2.896649704
##  [56] -1.507575269  0.167025748 -1.362883701 -1.163388675 -0.453860137
##  [61] -0.082191647  2.081975145 -0.731771731  0.447599146 -0.949067464
##  [66] -0.981865970 -1.253537117 -0.652734853  0.230514709  0.508389876
##  [71] -0.335137033 -0.577333952  1.125884853  1.884175410  1.868599712
##  [76] -0.373986078  0.540078189  0.326100544  0.922779061 -0.676952910
##  [81] -1.021652887 -2.455669492 -0.525253954 -0.756449866  0.242026733
##  [86] -0.793622237 -2.118250559 -1.171944294 -1.254756058  0.156409896
##  [91]  0.881224244  1.963714779  1.319895662 -0.541030517  0.372948487
##  [96] -1.269736070  1.185564889 -0.749225458  1.348942202  0.610003501
## [101]  1.471093899  1.131809788 -0.449774717  0.528073425 -1.069169086
## [106]  0.655515959  0.813411637  1.980547838  0.292419372  2.056655613
## [111]  1.452182364  1.443411029  1.538886178 -0.586702602 -0.802033556
## [116] -1.632108730  0.130561699 -0.916958534  1.760703550  1.559644810
## [121]  1.713929615  1.637894941  0.880972909  1.384500177  2.096981934
## [126]  0.884207740 -0.279617376  0.291208970 -0.768094492 -1.086892414
## [131] -0.560696861  0.318145290  0.006487837 -0.294477306 -2.566374703
## [136] -1.711312552 -1.945850023  1.209309432  0.787209035  1.817054541
## [141]  0.042340797  0.371645997 -1.666279378 -0.450065553 -1.926881708
## [146]  0.845610896  0.317984728  2.453425058  0.616148527 -1.080111772
## [151] -0.732158983 -2.282823453 -0.856121205 -0.284745928 -2.527788313
## [156] -1.583975853 -0.262485375  0.350113476  2.062510435  1.118959736
## [161]  0.810890964  0.361658001 -0.762405075  0.174734931 -1.333189977
## [166] -1.444625441 -2.294630100 -2.423037666  0.913607099  1.283219664
## [171]  2.669925684  2.144997162  1.016223907  2.781621020  2.229933096
## [176]  1.563078926  2.121133394 -0.124324765  0.666300793 -1.560166674
## [181] -1.736651137 -3.875143179 -3.522676167 -2.360833581 -1.000336996
## [186] -0.843211137 -0.135650765 -0.709671480  1.390898586 -0.096231517
## [191]  0.739315875  0.951040561  0.324689822  0.833814176  1.129219631
## [196]  1.207678300 -1.383559378 -0.683797515  0.092205088  0.132851910
## [201] -0.348714809 -0.020167567 -1.108436389 -2.394337109 -0.581490203
## [206] -2.833926427 -1.884126069  0.288866728  0.292297373  0.451081021
## [211] -0.030659568  0.245960795  1.332739654  0.941277885  1.933980662
## [216]  0.055740608  0.995855870  1.134146672  1.705224826  1.257882265
## [221]  0.688890766  0.979865547  0.082975177  0.745006291  0.426795522
## [226]  1.023379835  0.122487130 -0.648209322 -3.208880364 -0.473769727
## [231] -0.133838137  1.866038951  1.498457094 -0.849790736 -0.178248189
## [236] -1.921776375 -0.629875868 -1.580832048  0.598432589 -0.159793430
## [241]  0.880989211  0.987022925  0.514417044  0.074549124  0.662336368
## [246] -1.918440785 -0.045150758 -0.469879540  0.811847904  0.304228772
## [251] -0.298448803 -1.353749214 -1.554844881 -0.290228437 -1.934766491
## [256] -0.092434755 -3.369647389 -2.324057797 -1.958702604 -0.530963197
## [261] -0.908340921  0.324453692 -1.154031550 -1.415538487 -0.882397739
## [266] -0.111151421 -0.652326891  0.270556538 -0.805420362  0.272980086
## [271] -0.057273789  0.859319788 -1.786286310 -2.927631672 -2.497477692
## [276] -0.851240606  0.312379603 -0.187899331 -0.890509851 -1.178938323
## [281]  0.274957064 -1.013144834 -0.549619209 -0.103440636 -0.030645415
## [286]  1.420424337 -0.710422968  1.709037642 -1.476237380  1.602330567
## [291] -2.399768731  0.667900943 -1.152654377  0.723381614 -0.155364848
## [296]  1.416746072  0.894366166  1.313866117 -2.067594319
plot(y=yt_ma,x=yt_1_ma)

Berdasarkan scatterplot tersebut, terlihat bahwa terdapat hubungan positif lemah antara \(Y_t\) dengan \(Y_{t-1}\). Hal ini sesuai dengan teori yang ada

cor(yt_ma,yt_1_ma)
## [1] 0.4385996

Korelasi antara \(Y_t\) dengan \(Y_{t-1}\) hasil simulasi mendekati teori yang ada yaitu

\[ \rho_1=\frac{-\theta_{1}+\theta_{1}\theta_{2}}{1+\theta_{1}^2+\theta_{2}^2}=\frac{(-0.4)+(0.4)(0.6)}{1+(0.4)^2+(0.6)^2}=0.105 \]

Korelasi antara \(Y_t\) dengan \(Y_{t-2}\)

#Yt
yt_ma2 <- ma[-c(1,2)]
yt_ma2
##   [1]  1.272939391  1.049329503  0.528455337 -0.660323932 -0.867766297
##   [6] -1.167038680 -1.276285900 -0.756024562  0.102562145 -1.673677061
##  [11] -0.414898173 -2.635847349  0.643421450 -2.470738795  0.807116406
##  [16] -2.435734193  0.789594500 -1.211021488  0.309792804 -2.591360944
##  [21] -1.551970879 -1.163496898  0.355554852  0.035818895  0.190514914
##  [26] -0.481533808  0.335096222  0.439786757 -0.586768006 -0.180757528
##  [31]  0.476906074  1.377054627  0.453350539  1.089294028 -1.102237824
##  [36]  0.290631381 -1.579802794 -0.654088463 -1.806967638 -1.015694637
##  [41] -2.271583889 -1.296964313 -1.282248111 -3.416281679 -1.394294840
##  [46] -2.096391138 -0.385318133  0.433415090 -0.571718551 -0.781329468
##  [51] -2.274489251 -2.495999349 -2.896649704 -1.507575269  0.167025748
##  [56] -1.362883701 -1.163388675 -0.453860137 -0.082191647  2.081975145
##  [61] -0.731771731  0.447599146 -0.949067464 -0.981865970 -1.253537117
##  [66] -0.652734853  0.230514709  0.508389876 -0.335137033 -0.577333952
##  [71]  1.125884853  1.884175410  1.868599712 -0.373986078  0.540078189
##  [76]  0.326100544  0.922779061 -0.676952910 -1.021652887 -2.455669492
##  [81] -0.525253954 -0.756449866  0.242026733 -0.793622237 -2.118250559
##  [86] -1.171944294 -1.254756058  0.156409896  0.881224244  1.963714779
##  [91]  1.319895662 -0.541030517  0.372948487 -1.269736070  1.185564889
##  [96] -0.749225458  1.348942202  0.610003501  1.471093899  1.131809788
## [101] -0.449774717  0.528073425 -1.069169086  0.655515959  0.813411637
## [106]  1.980547838  0.292419372  2.056655613  1.452182364  1.443411029
## [111]  1.538886178 -0.586702602 -0.802033556 -1.632108730  0.130561699
## [116] -0.916958534  1.760703550  1.559644810  1.713929615  1.637894941
## [121]  0.880972909  1.384500177  2.096981934  0.884207740 -0.279617376
## [126]  0.291208970 -0.768094492 -1.086892414 -0.560696861  0.318145290
## [131]  0.006487837 -0.294477306 -2.566374703 -1.711312552 -1.945850023
## [136]  1.209309432  0.787209035  1.817054541  0.042340797  0.371645997
## [141] -1.666279378 -0.450065553 -1.926881708  0.845610896  0.317984728
## [146]  2.453425058  0.616148527 -1.080111772 -0.732158983 -2.282823453
## [151] -0.856121205 -0.284745928 -2.527788313 -1.583975853 -0.262485375
## [156]  0.350113476  2.062510435  1.118959736  0.810890964  0.361658001
## [161] -0.762405075  0.174734931 -1.333189977 -1.444625441 -2.294630100
## [166] -2.423037666  0.913607099  1.283219664  2.669925684  2.144997162
## [171]  1.016223907  2.781621020  2.229933096  1.563078926  2.121133394
## [176] -0.124324765  0.666300793 -1.560166674 -1.736651137 -3.875143179
## [181] -3.522676167 -2.360833581 -1.000336996 -0.843211137 -0.135650765
## [186] -0.709671480  1.390898586 -0.096231517  0.739315875  0.951040561
## [191]  0.324689822  0.833814176  1.129219631  1.207678300 -1.383559378
## [196] -0.683797515  0.092205088  0.132851910 -0.348714809 -0.020167567
## [201] -1.108436389 -2.394337109 -0.581490203 -2.833926427 -1.884126069
## [206]  0.288866728  0.292297373  0.451081021 -0.030659568  0.245960795
## [211]  1.332739654  0.941277885  1.933980662  0.055740608  0.995855870
## [216]  1.134146672  1.705224826  1.257882265  0.688890766  0.979865547
## [221]  0.082975177  0.745006291  0.426795522  1.023379835  0.122487130
## [226] -0.648209322 -3.208880364 -0.473769727 -0.133838137  1.866038951
## [231]  1.498457094 -0.849790736 -0.178248189 -1.921776375 -0.629875868
## [236] -1.580832048  0.598432589 -0.159793430  0.880989211  0.987022925
## [241]  0.514417044  0.074549124  0.662336368 -1.918440785 -0.045150758
## [246] -0.469879540  0.811847904  0.304228772 -0.298448803 -1.353749214
## [251] -1.554844881 -0.290228437 -1.934766491 -0.092434755 -3.369647389
## [256] -2.324057797 -1.958702604 -0.530963197 -0.908340921  0.324453692
## [261] -1.154031550 -1.415538487 -0.882397739 -0.111151421 -0.652326891
## [266]  0.270556538 -0.805420362  0.272980086 -0.057273789  0.859319788
## [271] -1.786286310 -2.927631672 -2.497477692 -0.851240606  0.312379603
## [276] -0.187899331 -0.890509851 -1.178938323  0.274957064 -1.013144834
## [281] -0.549619209 -0.103440636 -0.030645415  1.420424337 -0.710422968
## [286]  1.709037642 -1.476237380  1.602330567 -2.399768731  0.667900943
## [291] -1.152654377  0.723381614 -0.155364848  1.416746072  0.894366166
## [296]  1.313866117 -2.067594319 -1.228167575
#Yt-2
yt_2_ma <- ma[-c(299,300)]
yt_2_ma
##   [1]  0.376486659  2.891083265  1.272939391  1.049329503  0.528455337
##   [6] -0.660323932 -0.867766297 -1.167038680 -1.276285900 -0.756024562
##  [11]  0.102562145 -1.673677061 -0.414898173 -2.635847349  0.643421450
##  [16] -2.470738795  0.807116406 -2.435734193  0.789594500 -1.211021488
##  [21]  0.309792804 -2.591360944 -1.551970879 -1.163496898  0.355554852
##  [26]  0.035818895  0.190514914 -0.481533808  0.335096222  0.439786757
##  [31] -0.586768006 -0.180757528  0.476906074  1.377054627  0.453350539
##  [36]  1.089294028 -1.102237824  0.290631381 -1.579802794 -0.654088463
##  [41] -1.806967638 -1.015694637 -2.271583889 -1.296964313 -1.282248111
##  [46] -3.416281679 -1.394294840 -2.096391138 -0.385318133  0.433415090
##  [51] -0.571718551 -0.781329468 -2.274489251 -2.495999349 -2.896649704
##  [56] -1.507575269  0.167025748 -1.362883701 -1.163388675 -0.453860137
##  [61] -0.082191647  2.081975145 -0.731771731  0.447599146 -0.949067464
##  [66] -0.981865970 -1.253537117 -0.652734853  0.230514709  0.508389876
##  [71] -0.335137033 -0.577333952  1.125884853  1.884175410  1.868599712
##  [76] -0.373986078  0.540078189  0.326100544  0.922779061 -0.676952910
##  [81] -1.021652887 -2.455669492 -0.525253954 -0.756449866  0.242026733
##  [86] -0.793622237 -2.118250559 -1.171944294 -1.254756058  0.156409896
##  [91]  0.881224244  1.963714779  1.319895662 -0.541030517  0.372948487
##  [96] -1.269736070  1.185564889 -0.749225458  1.348942202  0.610003501
## [101]  1.471093899  1.131809788 -0.449774717  0.528073425 -1.069169086
## [106]  0.655515959  0.813411637  1.980547838  0.292419372  2.056655613
## [111]  1.452182364  1.443411029  1.538886178 -0.586702602 -0.802033556
## [116] -1.632108730  0.130561699 -0.916958534  1.760703550  1.559644810
## [121]  1.713929615  1.637894941  0.880972909  1.384500177  2.096981934
## [126]  0.884207740 -0.279617376  0.291208970 -0.768094492 -1.086892414
## [131] -0.560696861  0.318145290  0.006487837 -0.294477306 -2.566374703
## [136] -1.711312552 -1.945850023  1.209309432  0.787209035  1.817054541
## [141]  0.042340797  0.371645997 -1.666279378 -0.450065553 -1.926881708
## [146]  0.845610896  0.317984728  2.453425058  0.616148527 -1.080111772
## [151] -0.732158983 -2.282823453 -0.856121205 -0.284745928 -2.527788313
## [156] -1.583975853 -0.262485375  0.350113476  2.062510435  1.118959736
## [161]  0.810890964  0.361658001 -0.762405075  0.174734931 -1.333189977
## [166] -1.444625441 -2.294630100 -2.423037666  0.913607099  1.283219664
## [171]  2.669925684  2.144997162  1.016223907  2.781621020  2.229933096
## [176]  1.563078926  2.121133394 -0.124324765  0.666300793 -1.560166674
## [181] -1.736651137 -3.875143179 -3.522676167 -2.360833581 -1.000336996
## [186] -0.843211137 -0.135650765 -0.709671480  1.390898586 -0.096231517
## [191]  0.739315875  0.951040561  0.324689822  0.833814176  1.129219631
## [196]  1.207678300 -1.383559378 -0.683797515  0.092205088  0.132851910
## [201] -0.348714809 -0.020167567 -1.108436389 -2.394337109 -0.581490203
## [206] -2.833926427 -1.884126069  0.288866728  0.292297373  0.451081021
## [211] -0.030659568  0.245960795  1.332739654  0.941277885  1.933980662
## [216]  0.055740608  0.995855870  1.134146672  1.705224826  1.257882265
## [221]  0.688890766  0.979865547  0.082975177  0.745006291  0.426795522
## [226]  1.023379835  0.122487130 -0.648209322 -3.208880364 -0.473769727
## [231] -0.133838137  1.866038951  1.498457094 -0.849790736 -0.178248189
## [236] -1.921776375 -0.629875868 -1.580832048  0.598432589 -0.159793430
## [241]  0.880989211  0.987022925  0.514417044  0.074549124  0.662336368
## [246] -1.918440785 -0.045150758 -0.469879540  0.811847904  0.304228772
## [251] -0.298448803 -1.353749214 -1.554844881 -0.290228437 -1.934766491
## [256] -0.092434755 -3.369647389 -2.324057797 -1.958702604 -0.530963197
## [261] -0.908340921  0.324453692 -1.154031550 -1.415538487 -0.882397739
## [266] -0.111151421 -0.652326891  0.270556538 -0.805420362  0.272980086
## [271] -0.057273789  0.859319788 -1.786286310 -2.927631672 -2.497477692
## [276] -0.851240606  0.312379603 -0.187899331 -0.890509851 -1.178938323
## [281]  0.274957064 -1.013144834 -0.549619209 -0.103440636 -0.030645415
## [286]  1.420424337 -0.710422968  1.709037642 -1.476237380  1.602330567
## [291] -2.399768731  0.667900943 -1.152654377  0.723381614 -0.155364848
## [296]  1.416746072  0.894366166  1.313866117
plot(y=yt_ma2,x=yt_2_ma)

Berdasarkan scatterplot tersebut, terlihat bahwa terdapat hubungan yang positif antara \(Y_t\) dengan \(Y_{t-2}\).

cor(yt_ma2,yt_2_ma)
## [1] 0.4618698

Korelasi antara \(Y_t\) dengan \(Y_{t-2}\) hasil simulasi mendekati teori yang ada yaitu

\[ \rho_2=\frac{-\theta_{2}}{1+\theta_{1}^2+\theta_{2}^2}=\frac{-(-0.4)}{1+(0.4)^2+(0.6)^2}=0.2631 \]

Korelasi antara \(Y_t\) dengan \(Y_{t-3}\)

#Yt
yt_ma3 <- ma[-c(1,2,3)]
yt_ma3
##   [1]  1.049329503  0.528455337 -0.660323932 -0.867766297 -1.167038680
##   [6] -1.276285900 -0.756024562  0.102562145 -1.673677061 -0.414898173
##  [11] -2.635847349  0.643421450 -2.470738795  0.807116406 -2.435734193
##  [16]  0.789594500 -1.211021488  0.309792804 -2.591360944 -1.551970879
##  [21] -1.163496898  0.355554852  0.035818895  0.190514914 -0.481533808
##  [26]  0.335096222  0.439786757 -0.586768006 -0.180757528  0.476906074
##  [31]  1.377054627  0.453350539  1.089294028 -1.102237824  0.290631381
##  [36] -1.579802794 -0.654088463 -1.806967638 -1.015694637 -2.271583889
##  [41] -1.296964313 -1.282248111 -3.416281679 -1.394294840 -2.096391138
##  [46] -0.385318133  0.433415090 -0.571718551 -0.781329468 -2.274489251
##  [51] -2.495999349 -2.896649704 -1.507575269  0.167025748 -1.362883701
##  [56] -1.163388675 -0.453860137 -0.082191647  2.081975145 -0.731771731
##  [61]  0.447599146 -0.949067464 -0.981865970 -1.253537117 -0.652734853
##  [66]  0.230514709  0.508389876 -0.335137033 -0.577333952  1.125884853
##  [71]  1.884175410  1.868599712 -0.373986078  0.540078189  0.326100544
##  [76]  0.922779061 -0.676952910 -1.021652887 -2.455669492 -0.525253954
##  [81] -0.756449866  0.242026733 -0.793622237 -2.118250559 -1.171944294
##  [86] -1.254756058  0.156409896  0.881224244  1.963714779  1.319895662
##  [91] -0.541030517  0.372948487 -1.269736070  1.185564889 -0.749225458
##  [96]  1.348942202  0.610003501  1.471093899  1.131809788 -0.449774717
## [101]  0.528073425 -1.069169086  0.655515959  0.813411637  1.980547838
## [106]  0.292419372  2.056655613  1.452182364  1.443411029  1.538886178
## [111] -0.586702602 -0.802033556 -1.632108730  0.130561699 -0.916958534
## [116]  1.760703550  1.559644810  1.713929615  1.637894941  0.880972909
## [121]  1.384500177  2.096981934  0.884207740 -0.279617376  0.291208970
## [126] -0.768094492 -1.086892414 -0.560696861  0.318145290  0.006487837
## [131] -0.294477306 -2.566374703 -1.711312552 -1.945850023  1.209309432
## [136]  0.787209035  1.817054541  0.042340797  0.371645997 -1.666279378
## [141] -0.450065553 -1.926881708  0.845610896  0.317984728  2.453425058
## [146]  0.616148527 -1.080111772 -0.732158983 -2.282823453 -0.856121205
## [151] -0.284745928 -2.527788313 -1.583975853 -0.262485375  0.350113476
## [156]  2.062510435  1.118959736  0.810890964  0.361658001 -0.762405075
## [161]  0.174734931 -1.333189977 -1.444625441 -2.294630100 -2.423037666
## [166]  0.913607099  1.283219664  2.669925684  2.144997162  1.016223907
## [171]  2.781621020  2.229933096  1.563078926  2.121133394 -0.124324765
## [176]  0.666300793 -1.560166674 -1.736651137 -3.875143179 -3.522676167
## [181] -2.360833581 -1.000336996 -0.843211137 -0.135650765 -0.709671480
## [186]  1.390898586 -0.096231517  0.739315875  0.951040561  0.324689822
## [191]  0.833814176  1.129219631  1.207678300 -1.383559378 -0.683797515
## [196]  0.092205088  0.132851910 -0.348714809 -0.020167567 -1.108436389
## [201] -2.394337109 -0.581490203 -2.833926427 -1.884126069  0.288866728
## [206]  0.292297373  0.451081021 -0.030659568  0.245960795  1.332739654
## [211]  0.941277885  1.933980662  0.055740608  0.995855870  1.134146672
## [216]  1.705224826  1.257882265  0.688890766  0.979865547  0.082975177
## [221]  0.745006291  0.426795522  1.023379835  0.122487130 -0.648209322
## [226] -3.208880364 -0.473769727 -0.133838137  1.866038951  1.498457094
## [231] -0.849790736 -0.178248189 -1.921776375 -0.629875868 -1.580832048
## [236]  0.598432589 -0.159793430  0.880989211  0.987022925  0.514417044
## [241]  0.074549124  0.662336368 -1.918440785 -0.045150758 -0.469879540
## [246]  0.811847904  0.304228772 -0.298448803 -1.353749214 -1.554844881
## [251] -0.290228437 -1.934766491 -0.092434755 -3.369647389 -2.324057797
## [256] -1.958702604 -0.530963197 -0.908340921  0.324453692 -1.154031550
## [261] -1.415538487 -0.882397739 -0.111151421 -0.652326891  0.270556538
## [266] -0.805420362  0.272980086 -0.057273789  0.859319788 -1.786286310
## [271] -2.927631672 -2.497477692 -0.851240606  0.312379603 -0.187899331
## [276] -0.890509851 -1.178938323  0.274957064 -1.013144834 -0.549619209
## [281] -0.103440636 -0.030645415  1.420424337 -0.710422968  1.709037642
## [286] -1.476237380  1.602330567 -2.399768731  0.667900943 -1.152654377
## [291]  0.723381614 -0.155364848  1.416746072  0.894366166  1.313866117
## [296] -2.067594319 -1.228167575
#Yt-3
yt_3_ma <- ma[-c(298,299,300)]
yt_3_ma
##   [1]  0.376486659  2.891083265  1.272939391  1.049329503  0.528455337
##   [6] -0.660323932 -0.867766297 -1.167038680 -1.276285900 -0.756024562
##  [11]  0.102562145 -1.673677061 -0.414898173 -2.635847349  0.643421450
##  [16] -2.470738795  0.807116406 -2.435734193  0.789594500 -1.211021488
##  [21]  0.309792804 -2.591360944 -1.551970879 -1.163496898  0.355554852
##  [26]  0.035818895  0.190514914 -0.481533808  0.335096222  0.439786757
##  [31] -0.586768006 -0.180757528  0.476906074  1.377054627  0.453350539
##  [36]  1.089294028 -1.102237824  0.290631381 -1.579802794 -0.654088463
##  [41] -1.806967638 -1.015694637 -2.271583889 -1.296964313 -1.282248111
##  [46] -3.416281679 -1.394294840 -2.096391138 -0.385318133  0.433415090
##  [51] -0.571718551 -0.781329468 -2.274489251 -2.495999349 -2.896649704
##  [56] -1.507575269  0.167025748 -1.362883701 -1.163388675 -0.453860137
##  [61] -0.082191647  2.081975145 -0.731771731  0.447599146 -0.949067464
##  [66] -0.981865970 -1.253537117 -0.652734853  0.230514709  0.508389876
##  [71] -0.335137033 -0.577333952  1.125884853  1.884175410  1.868599712
##  [76] -0.373986078  0.540078189  0.326100544  0.922779061 -0.676952910
##  [81] -1.021652887 -2.455669492 -0.525253954 -0.756449866  0.242026733
##  [86] -0.793622237 -2.118250559 -1.171944294 -1.254756058  0.156409896
##  [91]  0.881224244  1.963714779  1.319895662 -0.541030517  0.372948487
##  [96] -1.269736070  1.185564889 -0.749225458  1.348942202  0.610003501
## [101]  1.471093899  1.131809788 -0.449774717  0.528073425 -1.069169086
## [106]  0.655515959  0.813411637  1.980547838  0.292419372  2.056655613
## [111]  1.452182364  1.443411029  1.538886178 -0.586702602 -0.802033556
## [116] -1.632108730  0.130561699 -0.916958534  1.760703550  1.559644810
## [121]  1.713929615  1.637894941  0.880972909  1.384500177  2.096981934
## [126]  0.884207740 -0.279617376  0.291208970 -0.768094492 -1.086892414
## [131] -0.560696861  0.318145290  0.006487837 -0.294477306 -2.566374703
## [136] -1.711312552 -1.945850023  1.209309432  0.787209035  1.817054541
## [141]  0.042340797  0.371645997 -1.666279378 -0.450065553 -1.926881708
## [146]  0.845610896  0.317984728  2.453425058  0.616148527 -1.080111772
## [151] -0.732158983 -2.282823453 -0.856121205 -0.284745928 -2.527788313
## [156] -1.583975853 -0.262485375  0.350113476  2.062510435  1.118959736
## [161]  0.810890964  0.361658001 -0.762405075  0.174734931 -1.333189977
## [166] -1.444625441 -2.294630100 -2.423037666  0.913607099  1.283219664
## [171]  2.669925684  2.144997162  1.016223907  2.781621020  2.229933096
## [176]  1.563078926  2.121133394 -0.124324765  0.666300793 -1.560166674
## [181] -1.736651137 -3.875143179 -3.522676167 -2.360833581 -1.000336996
## [186] -0.843211137 -0.135650765 -0.709671480  1.390898586 -0.096231517
## [191]  0.739315875  0.951040561  0.324689822  0.833814176  1.129219631
## [196]  1.207678300 -1.383559378 -0.683797515  0.092205088  0.132851910
## [201] -0.348714809 -0.020167567 -1.108436389 -2.394337109 -0.581490203
## [206] -2.833926427 -1.884126069  0.288866728  0.292297373  0.451081021
## [211] -0.030659568  0.245960795  1.332739654  0.941277885  1.933980662
## [216]  0.055740608  0.995855870  1.134146672  1.705224826  1.257882265
## [221]  0.688890766  0.979865547  0.082975177  0.745006291  0.426795522
## [226]  1.023379835  0.122487130 -0.648209322 -3.208880364 -0.473769727
## [231] -0.133838137  1.866038951  1.498457094 -0.849790736 -0.178248189
## [236] -1.921776375 -0.629875868 -1.580832048  0.598432589 -0.159793430
## [241]  0.880989211  0.987022925  0.514417044  0.074549124  0.662336368
## [246] -1.918440785 -0.045150758 -0.469879540  0.811847904  0.304228772
## [251] -0.298448803 -1.353749214 -1.554844881 -0.290228437 -1.934766491
## [256] -0.092434755 -3.369647389 -2.324057797 -1.958702604 -0.530963197
## [261] -0.908340921  0.324453692 -1.154031550 -1.415538487 -0.882397739
## [266] -0.111151421 -0.652326891  0.270556538 -0.805420362  0.272980086
## [271] -0.057273789  0.859319788 -1.786286310 -2.927631672 -2.497477692
## [276] -0.851240606  0.312379603 -0.187899331 -0.890509851 -1.178938323
## [281]  0.274957064 -1.013144834 -0.549619209 -0.103440636 -0.030645415
## [286]  1.420424337 -0.710422968  1.709037642 -1.476237380  1.602330567
## [291] -2.399768731  0.667900943 -1.152654377  0.723381614 -0.155364848
## [296]  1.416746072  0.894366166
plot(y=yt_ma3,x=yt_3_ma)

Berdasarkan scatterplot tersebut, terlihat bahwa terdapat hubungan negatif yang lemah antara \(Y_t\) dengan \(Y_{t-3}\).

cor(yt_ma3,yt_3_ma)
## [1] 0.02760745

Korelasi antara \(Y_t\) dengan \(Y_{t-3}\) hasil simulasi mendekati teori yang ada yaitu 0.

2. AR(2)

Bangkitkan model AR(2) dengan 𝜙1 = 0.5 dan 𝜙2 = 0.2 sebanyak300 data (Manual dan dengan arima.sim)

Pembangkitan Proses AR

Akan dicoba membangkitkan proses AR paling sederhana, yaitu AR(2) dengan \(\phi_1 = 0.5\) dan \(\phi_2 = 0.2\) sebanyak 300 observasi dan \(c=0\).

set.seed(023)

Nilai-nilai selanjutnya dapat dicari melalui loop. Bentuk loop dapat dilihat dari rumus AR(2) yang hendak dibangkitkan:

\[ Y_t = e_t+0.5Y_{t-1}+0.2Y_{t-2} \]

n<-length(wn)
n
## [1] 300
ar <- c(1:n) 
for (i in 3:n) {ar[i]<-wn[i]+0.5*ar[i-1]+0.2*ar[i-2]}
ar
##   [1]  1.000000000  2.000000000  1.090614090  0.303740953  1.220706614
##   [6]  0.055431893 -0.860069177 -0.763814548 -1.013104606 -1.024746573
##  [11] -0.190749421 -1.964440185 -1.084168557 -2.546830537 -0.163805092
##  [16] -2.625470071 -0.520565413 -2.330562320 -0.356683887 -1.293448679
##  [21] -0.696296818 -2.817508246 -2.228774904 -1.242679372 -0.477166856
##  [26] -0.948397369 -0.548562602 -0.677155524 -0.040557833  0.248900606
##  [31] -0.876912990 -0.414899587  0.700514003  1.226727082  0.173029045
##  [36]  1.077658886 -0.478859773  0.240171913 -1.029739786 -0.857744472
##  [41] -1.652991974 -1.371925429 -2.527689711 -2.006414485 -1.697042317
##  [46] -4.309856156 -2.551632262 -2.375228952 -1.953904993 -0.773732617
##  [51] -1.467093687 -1.800803685 -2.689637876 -3.055145914 -3.524593363
##  [56] -2.487164257 -0.860483997 -2.657462237 -2.625111721 -0.810322492
##  [61] -0.751295282  0.852472193 -1.119201409 -0.217546339 -0.513197817
##  [66] -1.312676356 -1.499136967 -0.761234010 -0.106182052 -0.077174738
##  [71] -0.790783457 -0.772674611  1.164705837  1.845422234  1.431690401
##  [76] -0.250034220  1.069761837  1.248576592  0.910474198 -0.459115417
##  [81] -0.646828743 -1.932719897 -0.654367150 -0.736231374 -0.512775984
##  [86] -1.178239465 -2.491811288 -1.468680169 -1.412525932 -0.779383689
##  [91]  0.228675243  1.429457566  0.951437457 -0.738407735  0.679455127
##  [96] -0.521027869  0.831148632 -0.392321001  1.027024400  1.044483278
## [101]  1.320793202  1.398183204 -0.053968464  0.870279347 -0.281542656
## [106]  0.600579792  1.254008083  1.983280000  0.434380958  2.252030355
## [111]  2.494636578  1.645526980  2.112408810  0.513638425 -0.248494834
## [116] -0.759507313  0.552981593 -0.742550338  1.257420039  1.952889009
## [121]  1.441923171  1.780223030  1.663598806  1.977092938  2.811486998
## [126]  1.615732162  0.270585613  1.300737311  0.259218777 -1.024407605
## [131] -0.188230925  0.758795331 -0.238155081 -0.664508544 -2.319440026
## [136] -1.809798337 -1.944033708  0.415737494  0.251533355  0.803151768
## [141] -0.002954494  0.356191367 -1.294687668 -0.555517088 -1.588497703
## [146]  0.348626193  0.304087875  1.743817428  0.671570924 -1.204329630
## [151] -0.287764963 -1.606278981 -1.336252858 -0.350985659 -2.940554116
## [156] -2.508363697 -0.218935815 -0.329636209  0.767289279  0.877416652
## [161]  0.593640716  0.497552323 -0.405884944  0.365509442 -0.955155275
## [166] -1.707772857 -2.184188936 -2.618999860  0.324972582  0.804592356
## [171]  1.428067784  1.936095067  1.268961662  3.160515013  3.199276524
## [176]  1.965440416  3.031093235  1.380683356  1.328931023 -0.315741963
## [181] -1.145620675 -3.255881063 -3.579650362 -2.540847296 -1.913200938
## [186] -2.277334637 -1.375824057 -1.423704990  0.428721624 -0.564711654
## [191] -0.109006398  1.045151871  0.287862455  0.544382218  1.510162304
## [196]  1.484624045 -1.295720697 -0.471106852  1.049615156  0.017815817
## [201] -0.891363346  0.229453872 -0.774494504 -2.854257508 -0.731788183
## [206] -2.603027190 -3.175628345 -0.128681079 -0.162409980 -1.058525795
## [211] -0.534004363  0.327107996  1.050522326  0.650963765  1.849193088
## [216]  0.548918607  1.054338023  1.910605778  2.115910041  1.553870795
## [221]  1.273646596  1.829774557  0.855603421  1.135061923  1.217332953
## [226]  1.462802992  0.559296780 -0.286046290 -2.647399257 -0.293231260
## [231]  0.324736612  0.916821592  1.096076142 -0.835335279 -0.093636347
## [236] -1.237545429 -0.920801410 -1.561225148  0.144966732 -0.331461714
## [241]  0.115087968  0.932564405  0.476096447 -0.060396091  0.929262499
## [246] -1.520610939 -0.348883293  0.145226538  0.429826559  0.003117157
## [251] -0.370782310 -1.210689600 -1.548993672 -0.343513104 -2.163874992
## [256] -0.974019981 -3.350688609 -3.327816731 -2.251139147 -1.480657835
## [261] -2.272831866 -0.861468811 -1.618398733 -2.446439648 -1.403459929
## [266] -0.480577260 -1.543547546 -0.614570295 -0.909202432 -0.339243436
## [271] -0.328120063  0.475111109 -1.911167985 -3.379165529 -2.311992834
## [276] -1.075837285 -0.846228618 -1.341411876 -1.541662624 -1.515489559
## [281] -0.179543314 -1.474802475 -1.422076341 -0.200772981 -0.348277583
## [286]  0.708385868 -0.816871759  1.329235053 -0.952546203  1.015823972
## [291] -1.700592384  0.092217559 -0.531606579  0.127451215 -0.205326825
## [296]  1.179778754  1.038048079  1.118985127 -1.739628715 -1.089895751

Selain menggunakan cara di atas, pembangkitan proses AR dapat dilakukan dengan fungsi arima.sim() sebagai berikut.

ar1 <- arima.sim(list(order=c(2,0,0), ar=c(0.5,0.2)), n=300)
ar1
## Time Series:
## Start = 1 
## End = 300 
## Frequency = 1 
##   [1] -0.473844877 -0.884413028  0.705892023 -0.484519445  0.065542897
##   [6] -0.617337681 -0.197378846 -1.368822819 -1.973814435 -1.462783464
##  [11] -0.948654294  0.540763481 -1.262284523  0.338093474  0.149464836
##  [16]  1.184608206  1.951295324  2.158527257  0.483897189 -0.542212787
##  [21] -1.803532892 -0.917892765 -0.841770384 -0.090985832 -0.443400631
##  [26]  1.021618421  0.183693445 -1.701642201 -0.113006453  0.823987347
##  [31] -0.461531550 -0.629576062 -0.129859974  0.779873697  1.316595687
##  [36]  0.417319239  0.469783285 -0.048569116  0.109567287  1.875833692
##  [41] -0.145474710 -0.668049887 -1.696421266 -0.234814007 -1.670069798
##  [46] -0.155990192 -0.841933837 -0.584740670  0.570738668  0.175392594
##  [51]  0.635253070  1.640074368 -1.471176476 -1.780224758 -1.663747649
##  [56] -1.176905256 -0.292458059  1.594453241  1.200293217  1.445053398
##  [61] -1.087597856 -0.805621823 -1.199605434 -0.232783104 -0.496066348
##  [66]  1.251348060  1.700197634  1.740309082  1.161675689  0.494554890
##  [71]  0.197299460  1.537290451  1.854745765  1.984045967  1.940970080
##  [76]  1.733127458  2.186179529 -0.467056341  0.255696259 -0.814062911
##  [81] -0.724059617  0.099851689  1.125373095 -1.657125926 -0.972163714
##  [86] -0.904592700  0.695242477  1.860782626  1.718941889  1.597810157
##  [91]  0.834323092  1.251290709 -0.108610987  0.391611459  0.016744165
##  [96] -1.144190320 -0.091011149 -0.313325191 -0.395842000 -0.330484264
## [101] -1.375431830  1.424750323  0.465748546  1.770469287  1.234746603
## [106]  0.764177550  1.326564516  1.520390724  0.074829824  0.533270741
## [111]  1.806964715  1.870511636  2.288324042 -0.956346047  0.352197981
## [116]  0.402580172  1.209265875  0.943171881  1.479333534  0.432729911
## [121]  1.106976375  0.403284008  0.095732322 -0.724627701  1.150535030
## [126]  1.700928796 -0.822520783 -0.888958220 -0.697561184  0.848661882
## [131]  0.240749634 -0.646835562 -1.075194216 -3.077529941 -2.914443488
## [136] -2.764697104 -1.747627955 -2.529742200 -1.925074322 -0.750847662
## [141] -1.354604448 -0.448972288 -1.180563418 -1.665157144 -1.469071336
## [146] -0.742060506 -1.833280965 -0.643753313 -0.339877588  0.050651310
## [151]  1.038090957  0.591710734 -0.252603861 -0.410094078 -0.699998032
## [156] -1.431327643 -0.653610368 -0.385076970 -0.115671763 -0.730186502
## [161]  0.136471076 -0.034013433  1.397101667  1.308528422  1.689376123
## [166] -0.312245943 -0.091307422  1.109514109 -0.133172469 -1.140454428
## [171] -0.101636836  0.071654384  0.976165477  0.827814255 -0.858504747
## [176]  0.282603334 -2.263080759 -0.786735542 -0.302149464 -1.500406606
## [181] -0.828325508 -1.661221934 -1.398488496 -0.975368384 -0.923676679
## [186] -1.845417791  0.174824075 -0.707765854 -0.756066528 -1.102218800
## [191]  1.659310283 -0.372517301 -1.991575490 -1.394429555 -0.542346487
## [196] -0.817992500 -1.613063389 -2.868238591 -0.296177064 -2.232524214
## [201] -1.695814346 -2.471745458 -0.345759130  0.452798172  0.081872856
## [206]  0.424783241  0.199870491 -0.212924497  0.588993300  0.743296422
## [211]  2.132352859  1.543426715  2.659576895  1.240394264  0.796516091
## [216]  1.149898529  1.135087175 -0.300795099  0.207199109  0.808099294
## [221] -1.449366864 -0.826101853 -0.910802589 -1.662498298 -2.555630281
## [226] -0.857536739 -1.205264329  0.432466289 -0.822788291 -0.229031629
## [231] -0.409577471  1.137835143  0.236982771 -1.018024812 -1.272183345
## [236]  0.242741579  1.161597736 -0.187314292  0.614661724  0.643031287
## [241] -0.575152488  0.079842720 -1.949520180  0.022399799  1.861418699
## [246]  0.243334794  0.899342666 -0.561495785 -0.522588685 -1.778763924
## [251] -0.681113062 -1.444845461  0.806178461 -0.772729306 -0.889776737
## [256]  0.106456231 -1.069638128 -0.081983568  0.504147039  0.132721291
## [261]  0.231308129  0.682712768  0.390732679  0.207268037  0.022848960
## [266]  0.739499456 -1.335867265  1.155672687  0.395417437 -0.642945835
## [271] -1.282604742 -0.309494703 -1.302950397 -0.284116719  1.975221251
## [276]  0.304437087  1.856300742  0.856060938 -0.808413609 -1.540636262
## [281] -0.977149533 -0.007811559 -0.688677928  0.524259023  1.669615398
## [286]  0.619897457  1.181548319  1.751590183 -1.920436642 -0.042981489
## [291] -0.460509699  0.634765141  0.487619074  0.388611835 -2.403988536
## [296] -0.375178707 -0.723742110 -1.975609414 -1.510747832 -0.733001614

Buat plot time series, plot ACF, plot PACF dan plot EACF. Idenifikasi apakah data tersebut stasioner

Plot Time Series

ts.plot(ar)

Berdasarkan plot time series tersebut terlihat bahwa data cenderung stasioner pada rataan

Plot ACF

acf(ar)

Berdasarkan plot ACF tersebut terlihat bahwa plot ACF cenderung tails off dan cenderung membentuk pola grafik sinus

Plot PACF

pacf(ar)

Berdasarkan plot PACF tersebut, terlihat bahwa plot PACF cuts off pada lag pertama, sejalan dengan teori yang ada

Plot EACF

TSA::eacf(ar)
## AR/MA
##   0 1 2 3 4 5 6 7 8 9 10 11 12 13
## 0 x x x x x x o o o o o  o  o  o 
## 1 x x o x x x o o o o o  o  o  o 
## 2 x o o o o x o o o o o  o  o  o 
## 3 x o x o o x o o o o o  o  o  o 
## 4 x x o o o x o o o o o  o  o  o 
## 5 x x o o o o o o o o o  o  o  o 
## 6 x x x x x o o o o o o  o  o  o 
## 7 x x x o o o o o o o o  o  o  o

Berdasarkan pola segitiga nol pada plot EACF, terlihat bahwa segitiga nol berada pada ordo AR(1) dan ordo MA(1)

Dapat disimpulkan bahwa data tersebut stasioner

Buat scatterplot dan korelasi antara \(Y_t\) dengan \(Y_{t-1}\), \(Y_t\) dengan \(Y_{t-2}\), serta \(Y_t\) dengan \(Y_{t-3}\)

Scatterplot Antar Lag

Korelasi antara \(Y_t\) dengan \(Y_{t-1}\)

#Yt
yt_ar <- ar[-1]
yt_ar
##   [1]  2.000000000  1.090614090  0.303740953  1.220706614  0.055431893
##   [6] -0.860069177 -0.763814548 -1.013104606 -1.024746573 -0.190749421
##  [11] -1.964440185 -1.084168557 -2.546830537 -0.163805092 -2.625470071
##  [16] -0.520565413 -2.330562320 -0.356683887 -1.293448679 -0.696296818
##  [21] -2.817508246 -2.228774904 -1.242679372 -0.477166856 -0.948397369
##  [26] -0.548562602 -0.677155524 -0.040557833  0.248900606 -0.876912990
##  [31] -0.414899587  0.700514003  1.226727082  0.173029045  1.077658886
##  [36] -0.478859773  0.240171913 -1.029739786 -0.857744472 -1.652991974
##  [41] -1.371925429 -2.527689711 -2.006414485 -1.697042317 -4.309856156
##  [46] -2.551632262 -2.375228952 -1.953904993 -0.773732617 -1.467093687
##  [51] -1.800803685 -2.689637876 -3.055145914 -3.524593363 -2.487164257
##  [56] -0.860483997 -2.657462237 -2.625111721 -0.810322492 -0.751295282
##  [61]  0.852472193 -1.119201409 -0.217546339 -0.513197817 -1.312676356
##  [66] -1.499136967 -0.761234010 -0.106182052 -0.077174738 -0.790783457
##  [71] -0.772674611  1.164705837  1.845422234  1.431690401 -0.250034220
##  [76]  1.069761837  1.248576592  0.910474198 -0.459115417 -0.646828743
##  [81] -1.932719897 -0.654367150 -0.736231374 -0.512775984 -1.178239465
##  [86] -2.491811288 -1.468680169 -1.412525932 -0.779383689  0.228675243
##  [91]  1.429457566  0.951437457 -0.738407735  0.679455127 -0.521027869
##  [96]  0.831148632 -0.392321001  1.027024400  1.044483278  1.320793202
## [101]  1.398183204 -0.053968464  0.870279347 -0.281542656  0.600579792
## [106]  1.254008083  1.983280000  0.434380958  2.252030355  2.494636578
## [111]  1.645526980  2.112408810  0.513638425 -0.248494834 -0.759507313
## [116]  0.552981593 -0.742550338  1.257420039  1.952889009  1.441923171
## [121]  1.780223030  1.663598806  1.977092938  2.811486998  1.615732162
## [126]  0.270585613  1.300737311  0.259218777 -1.024407605 -0.188230925
## [131]  0.758795331 -0.238155081 -0.664508544 -2.319440026 -1.809798337
## [136] -1.944033708  0.415737494  0.251533355  0.803151768 -0.002954494
## [141]  0.356191367 -1.294687668 -0.555517088 -1.588497703  0.348626193
## [146]  0.304087875  1.743817428  0.671570924 -1.204329630 -0.287764963
## [151] -1.606278981 -1.336252858 -0.350985659 -2.940554116 -2.508363697
## [156] -0.218935815 -0.329636209  0.767289279  0.877416652  0.593640716
## [161]  0.497552323 -0.405884944  0.365509442 -0.955155275 -1.707772857
## [166] -2.184188936 -2.618999860  0.324972582  0.804592356  1.428067784
## [171]  1.936095067  1.268961662  3.160515013  3.199276524  1.965440416
## [176]  3.031093235  1.380683356  1.328931023 -0.315741963 -1.145620675
## [181] -3.255881063 -3.579650362 -2.540847296 -1.913200938 -2.277334637
## [186] -1.375824057 -1.423704990  0.428721624 -0.564711654 -0.109006398
## [191]  1.045151871  0.287862455  0.544382218  1.510162304  1.484624045
## [196] -1.295720697 -0.471106852  1.049615156  0.017815817 -0.891363346
## [201]  0.229453872 -0.774494504 -2.854257508 -0.731788183 -2.603027190
## [206] -3.175628345 -0.128681079 -0.162409980 -1.058525795 -0.534004363
## [211]  0.327107996  1.050522326  0.650963765  1.849193088  0.548918607
## [216]  1.054338023  1.910605778  2.115910041  1.553870795  1.273646596
## [221]  1.829774557  0.855603421  1.135061923  1.217332953  1.462802992
## [226]  0.559296780 -0.286046290 -2.647399257 -0.293231260  0.324736612
## [231]  0.916821592  1.096076142 -0.835335279 -0.093636347 -1.237545429
## [236] -0.920801410 -1.561225148  0.144966732 -0.331461714  0.115087968
## [241]  0.932564405  0.476096447 -0.060396091  0.929262499 -1.520610939
## [246] -0.348883293  0.145226538  0.429826559  0.003117157 -0.370782310
## [251] -1.210689600 -1.548993672 -0.343513104 -2.163874992 -0.974019981
## [256] -3.350688609 -3.327816731 -2.251139147 -1.480657835 -2.272831866
## [261] -0.861468811 -1.618398733 -2.446439648 -1.403459929 -0.480577260
## [266] -1.543547546 -0.614570295 -0.909202432 -0.339243436 -0.328120063
## [271]  0.475111109 -1.911167985 -3.379165529 -2.311992834 -1.075837285
## [276] -0.846228618 -1.341411876 -1.541662624 -1.515489559 -0.179543314
## [281] -1.474802475 -1.422076341 -0.200772981 -0.348277583  0.708385868
## [286] -0.816871759  1.329235053 -0.952546203  1.015823972 -1.700592384
## [291]  0.092217559 -0.531606579  0.127451215 -0.205326825  1.179778754
## [296]  1.038048079  1.118985127 -1.739628715 -1.089895751
#Yt-1
yt_1_ar <- ar[-300]
yt_1_ar
##   [1]  1.000000000  2.000000000  1.090614090  0.303740953  1.220706614
##   [6]  0.055431893 -0.860069177 -0.763814548 -1.013104606 -1.024746573
##  [11] -0.190749421 -1.964440185 -1.084168557 -2.546830537 -0.163805092
##  [16] -2.625470071 -0.520565413 -2.330562320 -0.356683887 -1.293448679
##  [21] -0.696296818 -2.817508246 -2.228774904 -1.242679372 -0.477166856
##  [26] -0.948397369 -0.548562602 -0.677155524 -0.040557833  0.248900606
##  [31] -0.876912990 -0.414899587  0.700514003  1.226727082  0.173029045
##  [36]  1.077658886 -0.478859773  0.240171913 -1.029739786 -0.857744472
##  [41] -1.652991974 -1.371925429 -2.527689711 -2.006414485 -1.697042317
##  [46] -4.309856156 -2.551632262 -2.375228952 -1.953904993 -0.773732617
##  [51] -1.467093687 -1.800803685 -2.689637876 -3.055145914 -3.524593363
##  [56] -2.487164257 -0.860483997 -2.657462237 -2.625111721 -0.810322492
##  [61] -0.751295282  0.852472193 -1.119201409 -0.217546339 -0.513197817
##  [66] -1.312676356 -1.499136967 -0.761234010 -0.106182052 -0.077174738
##  [71] -0.790783457 -0.772674611  1.164705837  1.845422234  1.431690401
##  [76] -0.250034220  1.069761837  1.248576592  0.910474198 -0.459115417
##  [81] -0.646828743 -1.932719897 -0.654367150 -0.736231374 -0.512775984
##  [86] -1.178239465 -2.491811288 -1.468680169 -1.412525932 -0.779383689
##  [91]  0.228675243  1.429457566  0.951437457 -0.738407735  0.679455127
##  [96] -0.521027869  0.831148632 -0.392321001  1.027024400  1.044483278
## [101]  1.320793202  1.398183204 -0.053968464  0.870279347 -0.281542656
## [106]  0.600579792  1.254008083  1.983280000  0.434380958  2.252030355
## [111]  2.494636578  1.645526980  2.112408810  0.513638425 -0.248494834
## [116] -0.759507313  0.552981593 -0.742550338  1.257420039  1.952889009
## [121]  1.441923171  1.780223030  1.663598806  1.977092938  2.811486998
## [126]  1.615732162  0.270585613  1.300737311  0.259218777 -1.024407605
## [131] -0.188230925  0.758795331 -0.238155081 -0.664508544 -2.319440026
## [136] -1.809798337 -1.944033708  0.415737494  0.251533355  0.803151768
## [141] -0.002954494  0.356191367 -1.294687668 -0.555517088 -1.588497703
## [146]  0.348626193  0.304087875  1.743817428  0.671570924 -1.204329630
## [151] -0.287764963 -1.606278981 -1.336252858 -0.350985659 -2.940554116
## [156] -2.508363697 -0.218935815 -0.329636209  0.767289279  0.877416652
## [161]  0.593640716  0.497552323 -0.405884944  0.365509442 -0.955155275
## [166] -1.707772857 -2.184188936 -2.618999860  0.324972582  0.804592356
## [171]  1.428067784  1.936095067  1.268961662  3.160515013  3.199276524
## [176]  1.965440416  3.031093235  1.380683356  1.328931023 -0.315741963
## [181] -1.145620675 -3.255881063 -3.579650362 -2.540847296 -1.913200938
## [186] -2.277334637 -1.375824057 -1.423704990  0.428721624 -0.564711654
## [191] -0.109006398  1.045151871  0.287862455  0.544382218  1.510162304
## [196]  1.484624045 -1.295720697 -0.471106852  1.049615156  0.017815817
## [201] -0.891363346  0.229453872 -0.774494504 -2.854257508 -0.731788183
## [206] -2.603027190 -3.175628345 -0.128681079 -0.162409980 -1.058525795
## [211] -0.534004363  0.327107996  1.050522326  0.650963765  1.849193088
## [216]  0.548918607  1.054338023  1.910605778  2.115910041  1.553870795
## [221]  1.273646596  1.829774557  0.855603421  1.135061923  1.217332953
## [226]  1.462802992  0.559296780 -0.286046290 -2.647399257 -0.293231260
## [231]  0.324736612  0.916821592  1.096076142 -0.835335279 -0.093636347
## [236] -1.237545429 -0.920801410 -1.561225148  0.144966732 -0.331461714
## [241]  0.115087968  0.932564405  0.476096447 -0.060396091  0.929262499
## [246] -1.520610939 -0.348883293  0.145226538  0.429826559  0.003117157
## [251] -0.370782310 -1.210689600 -1.548993672 -0.343513104 -2.163874992
## [256] -0.974019981 -3.350688609 -3.327816731 -2.251139147 -1.480657835
## [261] -2.272831866 -0.861468811 -1.618398733 -2.446439648 -1.403459929
## [266] -0.480577260 -1.543547546 -0.614570295 -0.909202432 -0.339243436
## [271] -0.328120063  0.475111109 -1.911167985 -3.379165529 -2.311992834
## [276] -1.075837285 -0.846228618 -1.341411876 -1.541662624 -1.515489559
## [281] -0.179543314 -1.474802475 -1.422076341 -0.200772981 -0.348277583
## [286]  0.708385868 -0.816871759  1.329235053 -0.952546203  1.015823972
## [291] -1.700592384  0.092217559 -0.531606579  0.127451215 -0.205326825
## [296]  1.179778754  1.038048079  1.118985127 -1.739628715
plot(y=yt_ar,x=yt_1_ar)

Berdasarkan scatterplot tersebut, terlihat bahwa terdapat hubungan positif antara \(Y_t\) dengan \(Y_{t-1}\). Hal ini sesuai dengan teori yang ada

cor(yt_ar,yt_1_ar)
## [1] 0.6621678

Korelasi antara \(Y_t\) dengan \(Y_{t-1}\) dari hasil simulasi mendekati perhitungan teoritis yaitu

\[ \rho_1=\frac{\phi_{1}}{1-\phi_{2}}=\frac{0.5}{1-0.2}=0.625 \]

Korelasi antara \(Y_t\) dengan \(Y_{t-2}\)

#Yt
yt_ar2 <- ar[-c(1,2)]
yt_ar2
##   [1]  1.090614090  0.303740953  1.220706614  0.055431893 -0.860069177
##   [6] -0.763814548 -1.013104606 -1.024746573 -0.190749421 -1.964440185
##  [11] -1.084168557 -2.546830537 -0.163805092 -2.625470071 -0.520565413
##  [16] -2.330562320 -0.356683887 -1.293448679 -0.696296818 -2.817508246
##  [21] -2.228774904 -1.242679372 -0.477166856 -0.948397369 -0.548562602
##  [26] -0.677155524 -0.040557833  0.248900606 -0.876912990 -0.414899587
##  [31]  0.700514003  1.226727082  0.173029045  1.077658886 -0.478859773
##  [36]  0.240171913 -1.029739786 -0.857744472 -1.652991974 -1.371925429
##  [41] -2.527689711 -2.006414485 -1.697042317 -4.309856156 -2.551632262
##  [46] -2.375228952 -1.953904993 -0.773732617 -1.467093687 -1.800803685
##  [51] -2.689637876 -3.055145914 -3.524593363 -2.487164257 -0.860483997
##  [56] -2.657462237 -2.625111721 -0.810322492 -0.751295282  0.852472193
##  [61] -1.119201409 -0.217546339 -0.513197817 -1.312676356 -1.499136967
##  [66] -0.761234010 -0.106182052 -0.077174738 -0.790783457 -0.772674611
##  [71]  1.164705837  1.845422234  1.431690401 -0.250034220  1.069761837
##  [76]  1.248576592  0.910474198 -0.459115417 -0.646828743 -1.932719897
##  [81] -0.654367150 -0.736231374 -0.512775984 -1.178239465 -2.491811288
##  [86] -1.468680169 -1.412525932 -0.779383689  0.228675243  1.429457566
##  [91]  0.951437457 -0.738407735  0.679455127 -0.521027869  0.831148632
##  [96] -0.392321001  1.027024400  1.044483278  1.320793202  1.398183204
## [101] -0.053968464  0.870279347 -0.281542656  0.600579792  1.254008083
## [106]  1.983280000  0.434380958  2.252030355  2.494636578  1.645526980
## [111]  2.112408810  0.513638425 -0.248494834 -0.759507313  0.552981593
## [116] -0.742550338  1.257420039  1.952889009  1.441923171  1.780223030
## [121]  1.663598806  1.977092938  2.811486998  1.615732162  0.270585613
## [126]  1.300737311  0.259218777 -1.024407605 -0.188230925  0.758795331
## [131] -0.238155081 -0.664508544 -2.319440026 -1.809798337 -1.944033708
## [136]  0.415737494  0.251533355  0.803151768 -0.002954494  0.356191367
## [141] -1.294687668 -0.555517088 -1.588497703  0.348626193  0.304087875
## [146]  1.743817428  0.671570924 -1.204329630 -0.287764963 -1.606278981
## [151] -1.336252858 -0.350985659 -2.940554116 -2.508363697 -0.218935815
## [156] -0.329636209  0.767289279  0.877416652  0.593640716  0.497552323
## [161] -0.405884944  0.365509442 -0.955155275 -1.707772857 -2.184188936
## [166] -2.618999860  0.324972582  0.804592356  1.428067784  1.936095067
## [171]  1.268961662  3.160515013  3.199276524  1.965440416  3.031093235
## [176]  1.380683356  1.328931023 -0.315741963 -1.145620675 -3.255881063
## [181] -3.579650362 -2.540847296 -1.913200938 -2.277334637 -1.375824057
## [186] -1.423704990  0.428721624 -0.564711654 -0.109006398  1.045151871
## [191]  0.287862455  0.544382218  1.510162304  1.484624045 -1.295720697
## [196] -0.471106852  1.049615156  0.017815817 -0.891363346  0.229453872
## [201] -0.774494504 -2.854257508 -0.731788183 -2.603027190 -3.175628345
## [206] -0.128681079 -0.162409980 -1.058525795 -0.534004363  0.327107996
## [211]  1.050522326  0.650963765  1.849193088  0.548918607  1.054338023
## [216]  1.910605778  2.115910041  1.553870795  1.273646596  1.829774557
## [221]  0.855603421  1.135061923  1.217332953  1.462802992  0.559296780
## [226] -0.286046290 -2.647399257 -0.293231260  0.324736612  0.916821592
## [231]  1.096076142 -0.835335279 -0.093636347 -1.237545429 -0.920801410
## [236] -1.561225148  0.144966732 -0.331461714  0.115087968  0.932564405
## [241]  0.476096447 -0.060396091  0.929262499 -1.520610939 -0.348883293
## [246]  0.145226538  0.429826559  0.003117157 -0.370782310 -1.210689600
## [251] -1.548993672 -0.343513104 -2.163874992 -0.974019981 -3.350688609
## [256] -3.327816731 -2.251139147 -1.480657835 -2.272831866 -0.861468811
## [261] -1.618398733 -2.446439648 -1.403459929 -0.480577260 -1.543547546
## [266] -0.614570295 -0.909202432 -0.339243436 -0.328120063  0.475111109
## [271] -1.911167985 -3.379165529 -2.311992834 -1.075837285 -0.846228618
## [276] -1.341411876 -1.541662624 -1.515489559 -0.179543314 -1.474802475
## [281] -1.422076341 -0.200772981 -0.348277583  0.708385868 -0.816871759
## [286]  1.329235053 -0.952546203  1.015823972 -1.700592384  0.092217559
## [291] -0.531606579  0.127451215 -0.205326825  1.179778754  1.038048079
## [296]  1.118985127 -1.739628715 -1.089895751
#Yt-2
yt_2_ar <- ar[-c(299,300)]
yt_2_ar
##   [1]  1.000000000  2.000000000  1.090614090  0.303740953  1.220706614
##   [6]  0.055431893 -0.860069177 -0.763814548 -1.013104606 -1.024746573
##  [11] -0.190749421 -1.964440185 -1.084168557 -2.546830537 -0.163805092
##  [16] -2.625470071 -0.520565413 -2.330562320 -0.356683887 -1.293448679
##  [21] -0.696296818 -2.817508246 -2.228774904 -1.242679372 -0.477166856
##  [26] -0.948397369 -0.548562602 -0.677155524 -0.040557833  0.248900606
##  [31] -0.876912990 -0.414899587  0.700514003  1.226727082  0.173029045
##  [36]  1.077658886 -0.478859773  0.240171913 -1.029739786 -0.857744472
##  [41] -1.652991974 -1.371925429 -2.527689711 -2.006414485 -1.697042317
##  [46] -4.309856156 -2.551632262 -2.375228952 -1.953904993 -0.773732617
##  [51] -1.467093687 -1.800803685 -2.689637876 -3.055145914 -3.524593363
##  [56] -2.487164257 -0.860483997 -2.657462237 -2.625111721 -0.810322492
##  [61] -0.751295282  0.852472193 -1.119201409 -0.217546339 -0.513197817
##  [66] -1.312676356 -1.499136967 -0.761234010 -0.106182052 -0.077174738
##  [71] -0.790783457 -0.772674611  1.164705837  1.845422234  1.431690401
##  [76] -0.250034220  1.069761837  1.248576592  0.910474198 -0.459115417
##  [81] -0.646828743 -1.932719897 -0.654367150 -0.736231374 -0.512775984
##  [86] -1.178239465 -2.491811288 -1.468680169 -1.412525932 -0.779383689
##  [91]  0.228675243  1.429457566  0.951437457 -0.738407735  0.679455127
##  [96] -0.521027869  0.831148632 -0.392321001  1.027024400  1.044483278
## [101]  1.320793202  1.398183204 -0.053968464  0.870279347 -0.281542656
## [106]  0.600579792  1.254008083  1.983280000  0.434380958  2.252030355
## [111]  2.494636578  1.645526980  2.112408810  0.513638425 -0.248494834
## [116] -0.759507313  0.552981593 -0.742550338  1.257420039  1.952889009
## [121]  1.441923171  1.780223030  1.663598806  1.977092938  2.811486998
## [126]  1.615732162  0.270585613  1.300737311  0.259218777 -1.024407605
## [131] -0.188230925  0.758795331 -0.238155081 -0.664508544 -2.319440026
## [136] -1.809798337 -1.944033708  0.415737494  0.251533355  0.803151768
## [141] -0.002954494  0.356191367 -1.294687668 -0.555517088 -1.588497703
## [146]  0.348626193  0.304087875  1.743817428  0.671570924 -1.204329630
## [151] -0.287764963 -1.606278981 -1.336252858 -0.350985659 -2.940554116
## [156] -2.508363697 -0.218935815 -0.329636209  0.767289279  0.877416652
## [161]  0.593640716  0.497552323 -0.405884944  0.365509442 -0.955155275
## [166] -1.707772857 -2.184188936 -2.618999860  0.324972582  0.804592356
## [171]  1.428067784  1.936095067  1.268961662  3.160515013  3.199276524
## [176]  1.965440416  3.031093235  1.380683356  1.328931023 -0.315741963
## [181] -1.145620675 -3.255881063 -3.579650362 -2.540847296 -1.913200938
## [186] -2.277334637 -1.375824057 -1.423704990  0.428721624 -0.564711654
## [191] -0.109006398  1.045151871  0.287862455  0.544382218  1.510162304
## [196]  1.484624045 -1.295720697 -0.471106852  1.049615156  0.017815817
## [201] -0.891363346  0.229453872 -0.774494504 -2.854257508 -0.731788183
## [206] -2.603027190 -3.175628345 -0.128681079 -0.162409980 -1.058525795
## [211] -0.534004363  0.327107996  1.050522326  0.650963765  1.849193088
## [216]  0.548918607  1.054338023  1.910605778  2.115910041  1.553870795
## [221]  1.273646596  1.829774557  0.855603421  1.135061923  1.217332953
## [226]  1.462802992  0.559296780 -0.286046290 -2.647399257 -0.293231260
## [231]  0.324736612  0.916821592  1.096076142 -0.835335279 -0.093636347
## [236] -1.237545429 -0.920801410 -1.561225148  0.144966732 -0.331461714
## [241]  0.115087968  0.932564405  0.476096447 -0.060396091  0.929262499
## [246] -1.520610939 -0.348883293  0.145226538  0.429826559  0.003117157
## [251] -0.370782310 -1.210689600 -1.548993672 -0.343513104 -2.163874992
## [256] -0.974019981 -3.350688609 -3.327816731 -2.251139147 -1.480657835
## [261] -2.272831866 -0.861468811 -1.618398733 -2.446439648 -1.403459929
## [266] -0.480577260 -1.543547546 -0.614570295 -0.909202432 -0.339243436
## [271] -0.328120063  0.475111109 -1.911167985 -3.379165529 -2.311992834
## [276] -1.075837285 -0.846228618 -1.341411876 -1.541662624 -1.515489559
## [281] -0.179543314 -1.474802475 -1.422076341 -0.200772981 -0.348277583
## [286]  0.708385868 -0.816871759  1.329235053 -0.952546203  1.015823972
## [291] -1.700592384  0.092217559 -0.531606579  0.127451215 -0.205326825
## [296]  1.179778754  1.038048079  1.118985127
plot(y=yt_ar2,x=yt_2_ar)

Berdasarkan scatterplot tersebut, terlihat bahwa terdapat hubungan positif yang lemah antara \(Y_t\) dengan \(Y_{t-2}\). Hal ini sesuai dengan teori yang ada

cor(yt_ar2,yt_2_ar)
## [1] 0.5738651

Korelasi antara \(Y_t\) dengan \(Y_{t-2}\) dari hasil simulasi mendekati perhitungan teoritis yaitu

\[ \rho_2=\frac{\phi_{2}(1-\phi_{2})+\phi_{1}^2}{1-\phi_{2}}=\frac{0.2(1-0.2)+0.5^2}{1-0.2}=0.512 \]

Korelasi antara \(Y_t\) dengan \(Y_{t-3}\)

#Yt
yt_ar3 <- ar[-c(1,2,3)]
yt_ar3
##   [1]  0.303740953  1.220706614  0.055431893 -0.860069177 -0.763814548
##   [6] -1.013104606 -1.024746573 -0.190749421 -1.964440185 -1.084168557
##  [11] -2.546830537 -0.163805092 -2.625470071 -0.520565413 -2.330562320
##  [16] -0.356683887 -1.293448679 -0.696296818 -2.817508246 -2.228774904
##  [21] -1.242679372 -0.477166856 -0.948397369 -0.548562602 -0.677155524
##  [26] -0.040557833  0.248900606 -0.876912990 -0.414899587  0.700514003
##  [31]  1.226727082  0.173029045  1.077658886 -0.478859773  0.240171913
##  [36] -1.029739786 -0.857744472 -1.652991974 -1.371925429 -2.527689711
##  [41] -2.006414485 -1.697042317 -4.309856156 -2.551632262 -2.375228952
##  [46] -1.953904993 -0.773732617 -1.467093687 -1.800803685 -2.689637876
##  [51] -3.055145914 -3.524593363 -2.487164257 -0.860483997 -2.657462237
##  [56] -2.625111721 -0.810322492 -0.751295282  0.852472193 -1.119201409
##  [61] -0.217546339 -0.513197817 -1.312676356 -1.499136967 -0.761234010
##  [66] -0.106182052 -0.077174738 -0.790783457 -0.772674611  1.164705837
##  [71]  1.845422234  1.431690401 -0.250034220  1.069761837  1.248576592
##  [76]  0.910474198 -0.459115417 -0.646828743 -1.932719897 -0.654367150
##  [81] -0.736231374 -0.512775984 -1.178239465 -2.491811288 -1.468680169
##  [86] -1.412525932 -0.779383689  0.228675243  1.429457566  0.951437457
##  [91] -0.738407735  0.679455127 -0.521027869  0.831148632 -0.392321001
##  [96]  1.027024400  1.044483278  1.320793202  1.398183204 -0.053968464
## [101]  0.870279347 -0.281542656  0.600579792  1.254008083  1.983280000
## [106]  0.434380958  2.252030355  2.494636578  1.645526980  2.112408810
## [111]  0.513638425 -0.248494834 -0.759507313  0.552981593 -0.742550338
## [116]  1.257420039  1.952889009  1.441923171  1.780223030  1.663598806
## [121]  1.977092938  2.811486998  1.615732162  0.270585613  1.300737311
## [126]  0.259218777 -1.024407605 -0.188230925  0.758795331 -0.238155081
## [131] -0.664508544 -2.319440026 -1.809798337 -1.944033708  0.415737494
## [136]  0.251533355  0.803151768 -0.002954494  0.356191367 -1.294687668
## [141] -0.555517088 -1.588497703  0.348626193  0.304087875  1.743817428
## [146]  0.671570924 -1.204329630 -0.287764963 -1.606278981 -1.336252858
## [151] -0.350985659 -2.940554116 -2.508363697 -0.218935815 -0.329636209
## [156]  0.767289279  0.877416652  0.593640716  0.497552323 -0.405884944
## [161]  0.365509442 -0.955155275 -1.707772857 -2.184188936 -2.618999860
## [166]  0.324972582  0.804592356  1.428067784  1.936095067  1.268961662
## [171]  3.160515013  3.199276524  1.965440416  3.031093235  1.380683356
## [176]  1.328931023 -0.315741963 -1.145620675 -3.255881063 -3.579650362
## [181] -2.540847296 -1.913200938 -2.277334637 -1.375824057 -1.423704990
## [186]  0.428721624 -0.564711654 -0.109006398  1.045151871  0.287862455
## [191]  0.544382218  1.510162304  1.484624045 -1.295720697 -0.471106852
## [196]  1.049615156  0.017815817 -0.891363346  0.229453872 -0.774494504
## [201] -2.854257508 -0.731788183 -2.603027190 -3.175628345 -0.128681079
## [206] -0.162409980 -1.058525795 -0.534004363  0.327107996  1.050522326
## [211]  0.650963765  1.849193088  0.548918607  1.054338023  1.910605778
## [216]  2.115910041  1.553870795  1.273646596  1.829774557  0.855603421
## [221]  1.135061923  1.217332953  1.462802992  0.559296780 -0.286046290
## [226] -2.647399257 -0.293231260  0.324736612  0.916821592  1.096076142
## [231] -0.835335279 -0.093636347 -1.237545429 -0.920801410 -1.561225148
## [236]  0.144966732 -0.331461714  0.115087968  0.932564405  0.476096447
## [241] -0.060396091  0.929262499 -1.520610939 -0.348883293  0.145226538
## [246]  0.429826559  0.003117157 -0.370782310 -1.210689600 -1.548993672
## [251] -0.343513104 -2.163874992 -0.974019981 -3.350688609 -3.327816731
## [256] -2.251139147 -1.480657835 -2.272831866 -0.861468811 -1.618398733
## [261] -2.446439648 -1.403459929 -0.480577260 -1.543547546 -0.614570295
## [266] -0.909202432 -0.339243436 -0.328120063  0.475111109 -1.911167985
## [271] -3.379165529 -2.311992834 -1.075837285 -0.846228618 -1.341411876
## [276] -1.541662624 -1.515489559 -0.179543314 -1.474802475 -1.422076341
## [281] -0.200772981 -0.348277583  0.708385868 -0.816871759  1.329235053
## [286] -0.952546203  1.015823972 -1.700592384  0.092217559 -0.531606579
## [291]  0.127451215 -0.205326825  1.179778754  1.038048079  1.118985127
## [296] -1.739628715 -1.089895751
#Yt-3
yt_3_ar <- ar[-c(298,299,300)]
yt_3_ar
##   [1]  1.000000000  2.000000000  1.090614090  0.303740953  1.220706614
##   [6]  0.055431893 -0.860069177 -0.763814548 -1.013104606 -1.024746573
##  [11] -0.190749421 -1.964440185 -1.084168557 -2.546830537 -0.163805092
##  [16] -2.625470071 -0.520565413 -2.330562320 -0.356683887 -1.293448679
##  [21] -0.696296818 -2.817508246 -2.228774904 -1.242679372 -0.477166856
##  [26] -0.948397369 -0.548562602 -0.677155524 -0.040557833  0.248900606
##  [31] -0.876912990 -0.414899587  0.700514003  1.226727082  0.173029045
##  [36]  1.077658886 -0.478859773  0.240171913 -1.029739786 -0.857744472
##  [41] -1.652991974 -1.371925429 -2.527689711 -2.006414485 -1.697042317
##  [46] -4.309856156 -2.551632262 -2.375228952 -1.953904993 -0.773732617
##  [51] -1.467093687 -1.800803685 -2.689637876 -3.055145914 -3.524593363
##  [56] -2.487164257 -0.860483997 -2.657462237 -2.625111721 -0.810322492
##  [61] -0.751295282  0.852472193 -1.119201409 -0.217546339 -0.513197817
##  [66] -1.312676356 -1.499136967 -0.761234010 -0.106182052 -0.077174738
##  [71] -0.790783457 -0.772674611  1.164705837  1.845422234  1.431690401
##  [76] -0.250034220  1.069761837  1.248576592  0.910474198 -0.459115417
##  [81] -0.646828743 -1.932719897 -0.654367150 -0.736231374 -0.512775984
##  [86] -1.178239465 -2.491811288 -1.468680169 -1.412525932 -0.779383689
##  [91]  0.228675243  1.429457566  0.951437457 -0.738407735  0.679455127
##  [96] -0.521027869  0.831148632 -0.392321001  1.027024400  1.044483278
## [101]  1.320793202  1.398183204 -0.053968464  0.870279347 -0.281542656
## [106]  0.600579792  1.254008083  1.983280000  0.434380958  2.252030355
## [111]  2.494636578  1.645526980  2.112408810  0.513638425 -0.248494834
## [116] -0.759507313  0.552981593 -0.742550338  1.257420039  1.952889009
## [121]  1.441923171  1.780223030  1.663598806  1.977092938  2.811486998
## [126]  1.615732162  0.270585613  1.300737311  0.259218777 -1.024407605
## [131] -0.188230925  0.758795331 -0.238155081 -0.664508544 -2.319440026
## [136] -1.809798337 -1.944033708  0.415737494  0.251533355  0.803151768
## [141] -0.002954494  0.356191367 -1.294687668 -0.555517088 -1.588497703
## [146]  0.348626193  0.304087875  1.743817428  0.671570924 -1.204329630
## [151] -0.287764963 -1.606278981 -1.336252858 -0.350985659 -2.940554116
## [156] -2.508363697 -0.218935815 -0.329636209  0.767289279  0.877416652
## [161]  0.593640716  0.497552323 -0.405884944  0.365509442 -0.955155275
## [166] -1.707772857 -2.184188936 -2.618999860  0.324972582  0.804592356
## [171]  1.428067784  1.936095067  1.268961662  3.160515013  3.199276524
## [176]  1.965440416  3.031093235  1.380683356  1.328931023 -0.315741963
## [181] -1.145620675 -3.255881063 -3.579650362 -2.540847296 -1.913200938
## [186] -2.277334637 -1.375824057 -1.423704990  0.428721624 -0.564711654
## [191] -0.109006398  1.045151871  0.287862455  0.544382218  1.510162304
## [196]  1.484624045 -1.295720697 -0.471106852  1.049615156  0.017815817
## [201] -0.891363346  0.229453872 -0.774494504 -2.854257508 -0.731788183
## [206] -2.603027190 -3.175628345 -0.128681079 -0.162409980 -1.058525795
## [211] -0.534004363  0.327107996  1.050522326  0.650963765  1.849193088
## [216]  0.548918607  1.054338023  1.910605778  2.115910041  1.553870795
## [221]  1.273646596  1.829774557  0.855603421  1.135061923  1.217332953
## [226]  1.462802992  0.559296780 -0.286046290 -2.647399257 -0.293231260
## [231]  0.324736612  0.916821592  1.096076142 -0.835335279 -0.093636347
## [236] -1.237545429 -0.920801410 -1.561225148  0.144966732 -0.331461714
## [241]  0.115087968  0.932564405  0.476096447 -0.060396091  0.929262499
## [246] -1.520610939 -0.348883293  0.145226538  0.429826559  0.003117157
## [251] -0.370782310 -1.210689600 -1.548993672 -0.343513104 -2.163874992
## [256] -0.974019981 -3.350688609 -3.327816731 -2.251139147 -1.480657835
## [261] -2.272831866 -0.861468811 -1.618398733 -2.446439648 -1.403459929
## [266] -0.480577260 -1.543547546 -0.614570295 -0.909202432 -0.339243436
## [271] -0.328120063  0.475111109 -1.911167985 -3.379165529 -2.311992834
## [276] -1.075837285 -0.846228618 -1.341411876 -1.541662624 -1.515489559
## [281] -0.179543314 -1.474802475 -1.422076341 -0.200772981 -0.348277583
## [286]  0.708385868 -0.816871759  1.329235053 -0.952546203  1.015823972
## [291] -1.700592384  0.092217559 -0.531606579  0.127451215 -0.205326825
## [296]  1.179778754  1.038048079
plot(y=yt_ar3,x=yt_3_ar)

Berdasarkan scatterplot tersebut, terlihat bahwa terdapat hubungan positif yang lemah antara \(Y_t\) dengan \(Y_{t-3}\). Hal ini sesuai dengan teori yang ada

cor(yt_ar3,yt_3_ar)
## [1] 0.4163187

2. ARMA(2,2)

Bangkitkan model AR(2) dengan 𝜃1 = 0.5, 𝜃2 = 0.2 ,𝜙1 = 0.3 dan𝜙2 = 0.7 sebanyak 300 data (Manual dan arima.sim)

Pembangkitan proses ARMA

set.seed(023)
n = length(wn)
phi1 = 0.5
phi2 = 0.2

theta1 = 0.4
theta2 = 0.6

y.arma=c(1:n)
for (i in 3:n){y.arma[i] = phi1*y.arma[i-1] + phi2*y.arma[i-2] + theta1*wn[i-1] + theta2*wn[i-2] + wn[i]}
head(y.arma)
## [1] 1.000000 2.000000 2.472939 2.685799 2.365943 1.059807

Pembangkitan ARMA(p,q) juga dapat dilakukan dengan fungsi arima.sim sebagai berikut.

arma22 <- arima.sim(list(order=c(2,0,2), ar = c(0.5,0.2), ma = c(0.4,0.6)), n=300)
arma22
## Time Series:
## Start = 1 
## End = 300 
## Frequency = 1 
##   [1]  0.06795477 -0.73270762  0.29534872 -0.88177243 -0.40494262 -1.81814223
##   [7] -2.63974439 -3.07358274 -2.71804095 -0.71635658 -1.61516276  0.15764457
##  [13] -0.47266329  1.44725419  2.51482053  3.64981261  2.51808704  0.94646378
##  [19] -1.73007867 -1.96463282 -2.29104663 -0.97842919 -0.98485685  0.78966693
##  [25]  0.32630064 -1.01519362 -0.68344715 -0.24220047 -0.19974042 -0.31979622
##  [31] -0.65860929  0.35018410  1.55062920  1.41188175  1.42666841  0.38973575
##  [37]  0.37200962  1.89051914  0.67059914  0.39926045 -2.05092604 -1.31421244
##  [43] -2.78184816 -0.96490651 -1.90637179 -1.01510832 -0.16831790  0.05284366
##  [49]  1.04785331  1.99941115 -0.43399489 -1.38465073 -3.25854344 -2.91053917
##  [55] -1.76146875  0.77132686  1.66259968  2.88184263  0.21059943 -0.37362893
##  [61] -2.17441288 -1.19599837 -1.30894285  0.91325166  1.90309705  3.17119697
##  [67]  2.87791790  2.00341061  1.09212683  1.91294317  2.58804162  3.64831854
##  [73]  3.84743593  3.69994307  4.04401256  1.44729195  1.38058144 -0.99201821
##  [79] -0.89626703 -0.67820990  0.73087800 -1.14706567 -0.95979023 -2.28773374
##  [85] -0.24989283  1.59612400  2.88040043  3.40185649  2.50481229  2.54370604
##  [91]  0.89249915  1.09894149  0.10822216 -0.90252578 -0.53864078 -1.03624384
##  [97] -0.57577877 -0.67681618 -1.74513073  0.67628703  0.21038958  2.81161890
## [103]  2.22238345  2.32035776  2.37308350  2.50952306  1.47892482  1.47543711
## [109]  2.06517091  2.91325997  4.12070753  1.08129055  1.34265399 -0.03034826
## [115]  1.58161673  1.66842633  2.58216181  1.59036645  2.16766846  1.10571250
## [121]  0.92123175 -0.44436437  0.91812334  1.72636619  0.54817175 -0.19740926
## [127] -1.54665694  0.03626248  0.16167768 -0.04133858 -1.18947866 -3.89570896
## [133] -4.79057199 -5.77699246 -4.60217289 -4.88761164 -3.98554798 -3.03872271
## [139] -2.80998811 -1.44132266 -2.17291500 -2.40676588 -2.84347224 -2.32878333
## [145] -3.01154797 -1.82230200 -1.69734749 -0.47155171  0.85442493  1.03733790
## [151]  0.60693501 -0.15610918 -1.01559798 -1.95738330 -1.64614024 -1.50531770
## [157] -0.66186877 -1.00750139 -0.22500658 -0.41753690  1.46537894  1.84696103
## [163]  3.05104849  1.14862156  0.79741988  0.88564357  0.25584872 -0.52801495
## [169] -0.63772209 -0.65327301  0.94384513  1.26127308  0.05832024  0.43588999
## [175] -2.66514227 -1.52240584 -1.97469214 -2.09330772 -1.60977783 -2.89279610
## [181] -2.55997257 -2.53149694 -2.15291713 -2.80010949 -1.11754905 -1.74508690
## [187] -0.93427842 -1.82930492  0.76478285 -0.37012447 -1.14499624 -2.41457013
## [193] -2.29506360 -1.87158883 -2.26566828 -4.00425945 -2.41131053 -4.07193819
## [199] -2.76653027 -4.48958572 -2.35194592 -1.16855276  0.05553665  0.72921129
## [205]  0.41890750  0.12189364  0.62374580  0.85113904  2.78306741  2.84234571
## [211]  4.55635930  3.23028105  2.88841993  2.21274152  2.07295624  0.84317889
## [217]  0.76793337  0.71050188 -1.00180768 -0.92098902 -2.11086345 -2.52248045
## [223] -3.76711115 -2.87728783 -3.08165719 -0.56416149 -1.37296037 -0.29866717
## [229] -0.99486310  0.83658518  0.44637035 -0.24053062 -1.53720361 -0.87694665
## [235]  0.49538436  0.42296975  1.23669465  0.77650740  0.05085706  0.23560050
## [241] -2.26267459 -0.70950264  0.70066651  1.00134215  2.11352780 -0.05575784
## [247] -0.20758140 -2.32469687 -1.70617184 -2.78454904 -0.18042756 -1.31716520
## [253] -0.71516138 -0.71309205 -1.56092168 -0.44596508 -0.17042927  0.28518997
## [259]  0.58688487  0.85486879  0.80260266  0.77318877  0.34019578  0.87299986
## [265] -1.02635811  1.06502545  0.05616615  0.20862475 -1.30253261 -1.20830410
## [271] -2.19631112 -0.99099370  1.07980433  0.92405556  3.16320833  1.78124349
## [277]  0.64779121 -1.35036514 -2.07845220 -1.32305313 -1.27809227  0.24410092
## [283]  1.46611225  1.60229903  2.43127654  2.59614799 -0.51087158  0.23979796
## [289] -1.62996428  0.42477237  0.46521931  0.96451855 -1.95597236 -1.10360702
## [295] -2.31620671 -2.49021348 -2.73523686 -2.52266639 -0.96657601 -0.45523786

##Buat plot time series, plot ACF, plot PACF dan plot EACF. Idenifikasi apakah data tersebut stasioner

Plot Time Series

par(mfrow = c(1, 2))
ts.plot(y.arma)
ts.plot(arma22)

par(mfrow = c(1, 1))

Berdasarkan plot time series tersebut, terlihat bahwa model ARMA(2,2) cenderung stasioner dalam rataan

Plot ACF

par(mfrow = c(1, 2))
acf(y.arma)
acf(arma22)

par(mfrow = c(1, 1))

Berdasarkan plot ACF tersebut, terlihat bahwa model ARMA(1,1) hasil simulasi memiliki plot ACF yang tails off, sesuai dengan teori yang ada

Plot PACF

par(mfrow = c(1, 2))
pacf(y.arma)
pacf(arma22)

par(mfrow = c(1, 1))

Berdasarkan plot PACF tersebut, terlihat bahwa model ARMA(1,1) hasil simulasi memiliki plot PACF yang tails off, sesuai dengan teori

Plot EACF

TSA::eacf(y.arma)
## AR/MA
##   0 1 2 3 4 5 6 7 8 9 10 11 12 13
## 0 x x x x x x x o o o o  o  o  o 
## 1 o x x x o x o o o o o  o  o  o 
## 2 x x x x o x o o o o o  o  o  o 
## 3 x x x x o x o o o o o  o  o  o 
## 4 x x x x x x o o o o o  o  o  o 
## 5 x x x o o o o o o o o  o  o  o 
## 6 x x x o o o o o o o o  o  o  o 
## 7 x x x o o o o o o o o  o  o  o
TSA::eacf(arma22)
## AR/MA
##   0 1 2 3 4 5 6 7 8 9 10 11 12 13
## 0 x x x x x x x x o o o  o  o  o 
## 1 o x x o x o o o o o o  o  o  o 
## 2 o x o o x o o o o o o  o  o  o 
## 3 x x o x x o o o o o o  o  o  o 
## 4 x x o x x o o o o o o  o  o  o 
## 5 x x x o x o o o o o o  o  o  o 
## 6 x x o o x x o o o o o  o  o  o 
## 7 x o o x o x o x o o o  o  o  o

Berdasarkan pola segitiga nol pada plot EACF, terlihat bahwa segitiga nol berada pada ordo AR(1) dan ordo MA(5)

Dapat disimpulkan bahwa data tersebut stasioner

Buat scatterplot dan korelasi antara \(Y_t\) dengan \(Y_{t-1}\), \(Y_t\) dengan \(Y_{t-2}\), serta \(Y_t\) dengan \(Y_{t-3}\)

Korelasi antara \(Y_t\) dengan \(Y_{t-1}\)

#Yt
yt_arma <- arma22[-1]
yt_arma
##   [1] -0.73270762  0.29534872 -0.88177243 -0.40494262 -1.81814223 -2.63974439
##   [7] -3.07358274 -2.71804095 -0.71635658 -1.61516276  0.15764457 -0.47266329
##  [13]  1.44725419  2.51482053  3.64981261  2.51808704  0.94646378 -1.73007867
##  [19] -1.96463282 -2.29104663 -0.97842919 -0.98485685  0.78966693  0.32630064
##  [25] -1.01519362 -0.68344715 -0.24220047 -0.19974042 -0.31979622 -0.65860929
##  [31]  0.35018410  1.55062920  1.41188175  1.42666841  0.38973575  0.37200962
##  [37]  1.89051914  0.67059914  0.39926045 -2.05092604 -1.31421244 -2.78184816
##  [43] -0.96490651 -1.90637179 -1.01510832 -0.16831790  0.05284366  1.04785331
##  [49]  1.99941115 -0.43399489 -1.38465073 -3.25854344 -2.91053917 -1.76146875
##  [55]  0.77132686  1.66259968  2.88184263  0.21059943 -0.37362893 -2.17441288
##  [61] -1.19599837 -1.30894285  0.91325166  1.90309705  3.17119697  2.87791790
##  [67]  2.00341061  1.09212683  1.91294317  2.58804162  3.64831854  3.84743593
##  [73]  3.69994307  4.04401256  1.44729195  1.38058144 -0.99201821 -0.89626703
##  [79] -0.67820990  0.73087800 -1.14706567 -0.95979023 -2.28773374 -0.24989283
##  [85]  1.59612400  2.88040043  3.40185649  2.50481229  2.54370604  0.89249915
##  [91]  1.09894149  0.10822216 -0.90252578 -0.53864078 -1.03624384 -0.57577877
##  [97] -0.67681618 -1.74513073  0.67628703  0.21038958  2.81161890  2.22238345
## [103]  2.32035776  2.37308350  2.50952306  1.47892482  1.47543711  2.06517091
## [109]  2.91325997  4.12070753  1.08129055  1.34265399 -0.03034826  1.58161673
## [115]  1.66842633  2.58216181  1.59036645  2.16766846  1.10571250  0.92123175
## [121] -0.44436437  0.91812334  1.72636619  0.54817175 -0.19740926 -1.54665694
## [127]  0.03626248  0.16167768 -0.04133858 -1.18947866 -3.89570896 -4.79057199
## [133] -5.77699246 -4.60217289 -4.88761164 -3.98554798 -3.03872271 -2.80998811
## [139] -1.44132266 -2.17291500 -2.40676588 -2.84347224 -2.32878333 -3.01154797
## [145] -1.82230200 -1.69734749 -0.47155171  0.85442493  1.03733790  0.60693501
## [151] -0.15610918 -1.01559798 -1.95738330 -1.64614024 -1.50531770 -0.66186877
## [157] -1.00750139 -0.22500658 -0.41753690  1.46537894  1.84696103  3.05104849
## [163]  1.14862156  0.79741988  0.88564357  0.25584872 -0.52801495 -0.63772209
## [169] -0.65327301  0.94384513  1.26127308  0.05832024  0.43588999 -2.66514227
## [175] -1.52240584 -1.97469214 -2.09330772 -1.60977783 -2.89279610 -2.55997257
## [181] -2.53149694 -2.15291713 -2.80010949 -1.11754905 -1.74508690 -0.93427842
## [187] -1.82930492  0.76478285 -0.37012447 -1.14499624 -2.41457013 -2.29506360
## [193] -1.87158883 -2.26566828 -4.00425945 -2.41131053 -4.07193819 -2.76653027
## [199] -4.48958572 -2.35194592 -1.16855276  0.05553665  0.72921129  0.41890750
## [205]  0.12189364  0.62374580  0.85113904  2.78306741  2.84234571  4.55635930
## [211]  3.23028105  2.88841993  2.21274152  2.07295624  0.84317889  0.76793337
## [217]  0.71050188 -1.00180768 -0.92098902 -2.11086345 -2.52248045 -3.76711115
## [223] -2.87728783 -3.08165719 -0.56416149 -1.37296037 -0.29866717 -0.99486310
## [229]  0.83658518  0.44637035 -0.24053062 -1.53720361 -0.87694665  0.49538436
## [235]  0.42296975  1.23669465  0.77650740  0.05085706  0.23560050 -2.26267459
## [241] -0.70950264  0.70066651  1.00134215  2.11352780 -0.05575784 -0.20758140
## [247] -2.32469687 -1.70617184 -2.78454904 -0.18042756 -1.31716520 -0.71516138
## [253] -0.71309205 -1.56092168 -0.44596508 -0.17042927  0.28518997  0.58688487
## [259]  0.85486879  0.80260266  0.77318877  0.34019578  0.87299986 -1.02635811
## [265]  1.06502545  0.05616615  0.20862475 -1.30253261 -1.20830410 -2.19631112
## [271] -0.99099370  1.07980433  0.92405556  3.16320833  1.78124349  0.64779121
## [277] -1.35036514 -2.07845220 -1.32305313 -1.27809227  0.24410092  1.46611225
## [283]  1.60229903  2.43127654  2.59614799 -0.51087158  0.23979796 -1.62996428
## [289]  0.42477237  0.46521931  0.96451855 -1.95597236 -1.10360702 -2.31620671
## [295] -2.49021348 -2.73523686 -2.52266639 -0.96657601 -0.45523786
#Yt-1
yt_1_arma <- arma22[-300]
yt_1_arma
##   [1]  0.06795477 -0.73270762  0.29534872 -0.88177243 -0.40494262 -1.81814223
##   [7] -2.63974439 -3.07358274 -2.71804095 -0.71635658 -1.61516276  0.15764457
##  [13] -0.47266329  1.44725419  2.51482053  3.64981261  2.51808704  0.94646378
##  [19] -1.73007867 -1.96463282 -2.29104663 -0.97842919 -0.98485685  0.78966693
##  [25]  0.32630064 -1.01519362 -0.68344715 -0.24220047 -0.19974042 -0.31979622
##  [31] -0.65860929  0.35018410  1.55062920  1.41188175  1.42666841  0.38973575
##  [37]  0.37200962  1.89051914  0.67059914  0.39926045 -2.05092604 -1.31421244
##  [43] -2.78184816 -0.96490651 -1.90637179 -1.01510832 -0.16831790  0.05284366
##  [49]  1.04785331  1.99941115 -0.43399489 -1.38465073 -3.25854344 -2.91053917
##  [55] -1.76146875  0.77132686  1.66259968  2.88184263  0.21059943 -0.37362893
##  [61] -2.17441288 -1.19599837 -1.30894285  0.91325166  1.90309705  3.17119697
##  [67]  2.87791790  2.00341061  1.09212683  1.91294317  2.58804162  3.64831854
##  [73]  3.84743593  3.69994307  4.04401256  1.44729195  1.38058144 -0.99201821
##  [79] -0.89626703 -0.67820990  0.73087800 -1.14706567 -0.95979023 -2.28773374
##  [85] -0.24989283  1.59612400  2.88040043  3.40185649  2.50481229  2.54370604
##  [91]  0.89249915  1.09894149  0.10822216 -0.90252578 -0.53864078 -1.03624384
##  [97] -0.57577877 -0.67681618 -1.74513073  0.67628703  0.21038958  2.81161890
## [103]  2.22238345  2.32035776  2.37308350  2.50952306  1.47892482  1.47543711
## [109]  2.06517091  2.91325997  4.12070753  1.08129055  1.34265399 -0.03034826
## [115]  1.58161673  1.66842633  2.58216181  1.59036645  2.16766846  1.10571250
## [121]  0.92123175 -0.44436437  0.91812334  1.72636619  0.54817175 -0.19740926
## [127] -1.54665694  0.03626248  0.16167768 -0.04133858 -1.18947866 -3.89570896
## [133] -4.79057199 -5.77699246 -4.60217289 -4.88761164 -3.98554798 -3.03872271
## [139] -2.80998811 -1.44132266 -2.17291500 -2.40676588 -2.84347224 -2.32878333
## [145] -3.01154797 -1.82230200 -1.69734749 -0.47155171  0.85442493  1.03733790
## [151]  0.60693501 -0.15610918 -1.01559798 -1.95738330 -1.64614024 -1.50531770
## [157] -0.66186877 -1.00750139 -0.22500658 -0.41753690  1.46537894  1.84696103
## [163]  3.05104849  1.14862156  0.79741988  0.88564357  0.25584872 -0.52801495
## [169] -0.63772209 -0.65327301  0.94384513  1.26127308  0.05832024  0.43588999
## [175] -2.66514227 -1.52240584 -1.97469214 -2.09330772 -1.60977783 -2.89279610
## [181] -2.55997257 -2.53149694 -2.15291713 -2.80010949 -1.11754905 -1.74508690
## [187] -0.93427842 -1.82930492  0.76478285 -0.37012447 -1.14499624 -2.41457013
## [193] -2.29506360 -1.87158883 -2.26566828 -4.00425945 -2.41131053 -4.07193819
## [199] -2.76653027 -4.48958572 -2.35194592 -1.16855276  0.05553665  0.72921129
## [205]  0.41890750  0.12189364  0.62374580  0.85113904  2.78306741  2.84234571
## [211]  4.55635930  3.23028105  2.88841993  2.21274152  2.07295624  0.84317889
## [217]  0.76793337  0.71050188 -1.00180768 -0.92098902 -2.11086345 -2.52248045
## [223] -3.76711115 -2.87728783 -3.08165719 -0.56416149 -1.37296037 -0.29866717
## [229] -0.99486310  0.83658518  0.44637035 -0.24053062 -1.53720361 -0.87694665
## [235]  0.49538436  0.42296975  1.23669465  0.77650740  0.05085706  0.23560050
## [241] -2.26267459 -0.70950264  0.70066651  1.00134215  2.11352780 -0.05575784
## [247] -0.20758140 -2.32469687 -1.70617184 -2.78454904 -0.18042756 -1.31716520
## [253] -0.71516138 -0.71309205 -1.56092168 -0.44596508 -0.17042927  0.28518997
## [259]  0.58688487  0.85486879  0.80260266  0.77318877  0.34019578  0.87299986
## [265] -1.02635811  1.06502545  0.05616615  0.20862475 -1.30253261 -1.20830410
## [271] -2.19631112 -0.99099370  1.07980433  0.92405556  3.16320833  1.78124349
## [277]  0.64779121 -1.35036514 -2.07845220 -1.32305313 -1.27809227  0.24410092
## [283]  1.46611225  1.60229903  2.43127654  2.59614799 -0.51087158  0.23979796
## [289] -1.62996428  0.42477237  0.46521931  0.96451855 -1.95597236 -1.10360702
## [295] -2.31620671 -2.49021348 -2.73523686 -2.52266639 -0.96657601
plot(y=yt_arma,x=yt_1_arma)

Berdasarkan scatterplot tersebut, terlihat bahwa terdapat hubungan positif antara \(Y_t\) dengan \(Y_{t-1}\). Hal ini sesuai dengan teori yang ada

cor(yt_arma,yt_1_arma)
## [1] 0.7981987

Korelasi antara \(Y_t\) dengan \(Y_{t-2}\)

#Yt
yt_arma2 <- arma22[-c(1,2)]
yt_arma2
##   [1]  0.29534872 -0.88177243 -0.40494262 -1.81814223 -2.63974439 -3.07358274
##   [7] -2.71804095 -0.71635658 -1.61516276  0.15764457 -0.47266329  1.44725419
##  [13]  2.51482053  3.64981261  2.51808704  0.94646378 -1.73007867 -1.96463282
##  [19] -2.29104663 -0.97842919 -0.98485685  0.78966693  0.32630064 -1.01519362
##  [25] -0.68344715 -0.24220047 -0.19974042 -0.31979622 -0.65860929  0.35018410
##  [31]  1.55062920  1.41188175  1.42666841  0.38973575  0.37200962  1.89051914
##  [37]  0.67059914  0.39926045 -2.05092604 -1.31421244 -2.78184816 -0.96490651
##  [43] -1.90637179 -1.01510832 -0.16831790  0.05284366  1.04785331  1.99941115
##  [49] -0.43399489 -1.38465073 -3.25854344 -2.91053917 -1.76146875  0.77132686
##  [55]  1.66259968  2.88184263  0.21059943 -0.37362893 -2.17441288 -1.19599837
##  [61] -1.30894285  0.91325166  1.90309705  3.17119697  2.87791790  2.00341061
##  [67]  1.09212683  1.91294317  2.58804162  3.64831854  3.84743593  3.69994307
##  [73]  4.04401256  1.44729195  1.38058144 -0.99201821 -0.89626703 -0.67820990
##  [79]  0.73087800 -1.14706567 -0.95979023 -2.28773374 -0.24989283  1.59612400
##  [85]  2.88040043  3.40185649  2.50481229  2.54370604  0.89249915  1.09894149
##  [91]  0.10822216 -0.90252578 -0.53864078 -1.03624384 -0.57577877 -0.67681618
##  [97] -1.74513073  0.67628703  0.21038958  2.81161890  2.22238345  2.32035776
## [103]  2.37308350  2.50952306  1.47892482  1.47543711  2.06517091  2.91325997
## [109]  4.12070753  1.08129055  1.34265399 -0.03034826  1.58161673  1.66842633
## [115]  2.58216181  1.59036645  2.16766846  1.10571250  0.92123175 -0.44436437
## [121]  0.91812334  1.72636619  0.54817175 -0.19740926 -1.54665694  0.03626248
## [127]  0.16167768 -0.04133858 -1.18947866 -3.89570896 -4.79057199 -5.77699246
## [133] -4.60217289 -4.88761164 -3.98554798 -3.03872271 -2.80998811 -1.44132266
## [139] -2.17291500 -2.40676588 -2.84347224 -2.32878333 -3.01154797 -1.82230200
## [145] -1.69734749 -0.47155171  0.85442493  1.03733790  0.60693501 -0.15610918
## [151] -1.01559798 -1.95738330 -1.64614024 -1.50531770 -0.66186877 -1.00750139
## [157] -0.22500658 -0.41753690  1.46537894  1.84696103  3.05104849  1.14862156
## [163]  0.79741988  0.88564357  0.25584872 -0.52801495 -0.63772209 -0.65327301
## [169]  0.94384513  1.26127308  0.05832024  0.43588999 -2.66514227 -1.52240584
## [175] -1.97469214 -2.09330772 -1.60977783 -2.89279610 -2.55997257 -2.53149694
## [181] -2.15291713 -2.80010949 -1.11754905 -1.74508690 -0.93427842 -1.82930492
## [187]  0.76478285 -0.37012447 -1.14499624 -2.41457013 -2.29506360 -1.87158883
## [193] -2.26566828 -4.00425945 -2.41131053 -4.07193819 -2.76653027 -4.48958572
## [199] -2.35194592 -1.16855276  0.05553665  0.72921129  0.41890750  0.12189364
## [205]  0.62374580  0.85113904  2.78306741  2.84234571  4.55635930  3.23028105
## [211]  2.88841993  2.21274152  2.07295624  0.84317889  0.76793337  0.71050188
## [217] -1.00180768 -0.92098902 -2.11086345 -2.52248045 -3.76711115 -2.87728783
## [223] -3.08165719 -0.56416149 -1.37296037 -0.29866717 -0.99486310  0.83658518
## [229]  0.44637035 -0.24053062 -1.53720361 -0.87694665  0.49538436  0.42296975
## [235]  1.23669465  0.77650740  0.05085706  0.23560050 -2.26267459 -0.70950264
## [241]  0.70066651  1.00134215  2.11352780 -0.05575784 -0.20758140 -2.32469687
## [247] -1.70617184 -2.78454904 -0.18042756 -1.31716520 -0.71516138 -0.71309205
## [253] -1.56092168 -0.44596508 -0.17042927  0.28518997  0.58688487  0.85486879
## [259]  0.80260266  0.77318877  0.34019578  0.87299986 -1.02635811  1.06502545
## [265]  0.05616615  0.20862475 -1.30253261 -1.20830410 -2.19631112 -0.99099370
## [271]  1.07980433  0.92405556  3.16320833  1.78124349  0.64779121 -1.35036514
## [277] -2.07845220 -1.32305313 -1.27809227  0.24410092  1.46611225  1.60229903
## [283]  2.43127654  2.59614799 -0.51087158  0.23979796 -1.62996428  0.42477237
## [289]  0.46521931  0.96451855 -1.95597236 -1.10360702 -2.31620671 -2.49021348
## [295] -2.73523686 -2.52266639 -0.96657601 -0.45523786
#Yt-2
yt_2_arma <- arma22[-c(299,300)]
yt_2_arma
##   [1]  0.06795477 -0.73270762  0.29534872 -0.88177243 -0.40494262 -1.81814223
##   [7] -2.63974439 -3.07358274 -2.71804095 -0.71635658 -1.61516276  0.15764457
##  [13] -0.47266329  1.44725419  2.51482053  3.64981261  2.51808704  0.94646378
##  [19] -1.73007867 -1.96463282 -2.29104663 -0.97842919 -0.98485685  0.78966693
##  [25]  0.32630064 -1.01519362 -0.68344715 -0.24220047 -0.19974042 -0.31979622
##  [31] -0.65860929  0.35018410  1.55062920  1.41188175  1.42666841  0.38973575
##  [37]  0.37200962  1.89051914  0.67059914  0.39926045 -2.05092604 -1.31421244
##  [43] -2.78184816 -0.96490651 -1.90637179 -1.01510832 -0.16831790  0.05284366
##  [49]  1.04785331  1.99941115 -0.43399489 -1.38465073 -3.25854344 -2.91053917
##  [55] -1.76146875  0.77132686  1.66259968  2.88184263  0.21059943 -0.37362893
##  [61] -2.17441288 -1.19599837 -1.30894285  0.91325166  1.90309705  3.17119697
##  [67]  2.87791790  2.00341061  1.09212683  1.91294317  2.58804162  3.64831854
##  [73]  3.84743593  3.69994307  4.04401256  1.44729195  1.38058144 -0.99201821
##  [79] -0.89626703 -0.67820990  0.73087800 -1.14706567 -0.95979023 -2.28773374
##  [85] -0.24989283  1.59612400  2.88040043  3.40185649  2.50481229  2.54370604
##  [91]  0.89249915  1.09894149  0.10822216 -0.90252578 -0.53864078 -1.03624384
##  [97] -0.57577877 -0.67681618 -1.74513073  0.67628703  0.21038958  2.81161890
## [103]  2.22238345  2.32035776  2.37308350  2.50952306  1.47892482  1.47543711
## [109]  2.06517091  2.91325997  4.12070753  1.08129055  1.34265399 -0.03034826
## [115]  1.58161673  1.66842633  2.58216181  1.59036645  2.16766846  1.10571250
## [121]  0.92123175 -0.44436437  0.91812334  1.72636619  0.54817175 -0.19740926
## [127] -1.54665694  0.03626248  0.16167768 -0.04133858 -1.18947866 -3.89570896
## [133] -4.79057199 -5.77699246 -4.60217289 -4.88761164 -3.98554798 -3.03872271
## [139] -2.80998811 -1.44132266 -2.17291500 -2.40676588 -2.84347224 -2.32878333
## [145] -3.01154797 -1.82230200 -1.69734749 -0.47155171  0.85442493  1.03733790
## [151]  0.60693501 -0.15610918 -1.01559798 -1.95738330 -1.64614024 -1.50531770
## [157] -0.66186877 -1.00750139 -0.22500658 -0.41753690  1.46537894  1.84696103
## [163]  3.05104849  1.14862156  0.79741988  0.88564357  0.25584872 -0.52801495
## [169] -0.63772209 -0.65327301  0.94384513  1.26127308  0.05832024  0.43588999
## [175] -2.66514227 -1.52240584 -1.97469214 -2.09330772 -1.60977783 -2.89279610
## [181] -2.55997257 -2.53149694 -2.15291713 -2.80010949 -1.11754905 -1.74508690
## [187] -0.93427842 -1.82930492  0.76478285 -0.37012447 -1.14499624 -2.41457013
## [193] -2.29506360 -1.87158883 -2.26566828 -4.00425945 -2.41131053 -4.07193819
## [199] -2.76653027 -4.48958572 -2.35194592 -1.16855276  0.05553665  0.72921129
## [205]  0.41890750  0.12189364  0.62374580  0.85113904  2.78306741  2.84234571
## [211]  4.55635930  3.23028105  2.88841993  2.21274152  2.07295624  0.84317889
## [217]  0.76793337  0.71050188 -1.00180768 -0.92098902 -2.11086345 -2.52248045
## [223] -3.76711115 -2.87728783 -3.08165719 -0.56416149 -1.37296037 -0.29866717
## [229] -0.99486310  0.83658518  0.44637035 -0.24053062 -1.53720361 -0.87694665
## [235]  0.49538436  0.42296975  1.23669465  0.77650740  0.05085706  0.23560050
## [241] -2.26267459 -0.70950264  0.70066651  1.00134215  2.11352780 -0.05575784
## [247] -0.20758140 -2.32469687 -1.70617184 -2.78454904 -0.18042756 -1.31716520
## [253] -0.71516138 -0.71309205 -1.56092168 -0.44596508 -0.17042927  0.28518997
## [259]  0.58688487  0.85486879  0.80260266  0.77318877  0.34019578  0.87299986
## [265] -1.02635811  1.06502545  0.05616615  0.20862475 -1.30253261 -1.20830410
## [271] -2.19631112 -0.99099370  1.07980433  0.92405556  3.16320833  1.78124349
## [277]  0.64779121 -1.35036514 -2.07845220 -1.32305313 -1.27809227  0.24410092
## [283]  1.46611225  1.60229903  2.43127654  2.59614799 -0.51087158  0.23979796
## [289] -1.62996428  0.42477237  0.46521931  0.96451855 -1.95597236 -1.10360702
## [295] -2.31620671 -2.49021348 -2.73523686 -2.52266639
plot(y=yt_arma2,x=yt_2_arma)

Berdasarkan scatterplot tersebut, terlihat bahwa terdapat hubungan positif antara \(Y_t\) dengan \(Y_{t-1}\). Hal ini sesuai dengan teori yang ada

cor(yt_arma2,yt_2_arma)
## [1] 0.6546106

Korelasi antara \(Y_t\) dengan \(Y_{t-3}\)

#Yt
yt_arma3 <- arma22[-c(1,2,3)]
yt_arma3
##   [1] -0.88177243 -0.40494262 -1.81814223 -2.63974439 -3.07358274 -2.71804095
##   [7] -0.71635658 -1.61516276  0.15764457 -0.47266329  1.44725419  2.51482053
##  [13]  3.64981261  2.51808704  0.94646378 -1.73007867 -1.96463282 -2.29104663
##  [19] -0.97842919 -0.98485685  0.78966693  0.32630064 -1.01519362 -0.68344715
##  [25] -0.24220047 -0.19974042 -0.31979622 -0.65860929  0.35018410  1.55062920
##  [31]  1.41188175  1.42666841  0.38973575  0.37200962  1.89051914  0.67059914
##  [37]  0.39926045 -2.05092604 -1.31421244 -2.78184816 -0.96490651 -1.90637179
##  [43] -1.01510832 -0.16831790  0.05284366  1.04785331  1.99941115 -0.43399489
##  [49] -1.38465073 -3.25854344 -2.91053917 -1.76146875  0.77132686  1.66259968
##  [55]  2.88184263  0.21059943 -0.37362893 -2.17441288 -1.19599837 -1.30894285
##  [61]  0.91325166  1.90309705  3.17119697  2.87791790  2.00341061  1.09212683
##  [67]  1.91294317  2.58804162  3.64831854  3.84743593  3.69994307  4.04401256
##  [73]  1.44729195  1.38058144 -0.99201821 -0.89626703 -0.67820990  0.73087800
##  [79] -1.14706567 -0.95979023 -2.28773374 -0.24989283  1.59612400  2.88040043
##  [85]  3.40185649  2.50481229  2.54370604  0.89249915  1.09894149  0.10822216
##  [91] -0.90252578 -0.53864078 -1.03624384 -0.57577877 -0.67681618 -1.74513073
##  [97]  0.67628703  0.21038958  2.81161890  2.22238345  2.32035776  2.37308350
## [103]  2.50952306  1.47892482  1.47543711  2.06517091  2.91325997  4.12070753
## [109]  1.08129055  1.34265399 -0.03034826  1.58161673  1.66842633  2.58216181
## [115]  1.59036645  2.16766846  1.10571250  0.92123175 -0.44436437  0.91812334
## [121]  1.72636619  0.54817175 -0.19740926 -1.54665694  0.03626248  0.16167768
## [127] -0.04133858 -1.18947866 -3.89570896 -4.79057199 -5.77699246 -4.60217289
## [133] -4.88761164 -3.98554798 -3.03872271 -2.80998811 -1.44132266 -2.17291500
## [139] -2.40676588 -2.84347224 -2.32878333 -3.01154797 -1.82230200 -1.69734749
## [145] -0.47155171  0.85442493  1.03733790  0.60693501 -0.15610918 -1.01559798
## [151] -1.95738330 -1.64614024 -1.50531770 -0.66186877 -1.00750139 -0.22500658
## [157] -0.41753690  1.46537894  1.84696103  3.05104849  1.14862156  0.79741988
## [163]  0.88564357  0.25584872 -0.52801495 -0.63772209 -0.65327301  0.94384513
## [169]  1.26127308  0.05832024  0.43588999 -2.66514227 -1.52240584 -1.97469214
## [175] -2.09330772 -1.60977783 -2.89279610 -2.55997257 -2.53149694 -2.15291713
## [181] -2.80010949 -1.11754905 -1.74508690 -0.93427842 -1.82930492  0.76478285
## [187] -0.37012447 -1.14499624 -2.41457013 -2.29506360 -1.87158883 -2.26566828
## [193] -4.00425945 -2.41131053 -4.07193819 -2.76653027 -4.48958572 -2.35194592
## [199] -1.16855276  0.05553665  0.72921129  0.41890750  0.12189364  0.62374580
## [205]  0.85113904  2.78306741  2.84234571  4.55635930  3.23028105  2.88841993
## [211]  2.21274152  2.07295624  0.84317889  0.76793337  0.71050188 -1.00180768
## [217] -0.92098902 -2.11086345 -2.52248045 -3.76711115 -2.87728783 -3.08165719
## [223] -0.56416149 -1.37296037 -0.29866717 -0.99486310  0.83658518  0.44637035
## [229] -0.24053062 -1.53720361 -0.87694665  0.49538436  0.42296975  1.23669465
## [235]  0.77650740  0.05085706  0.23560050 -2.26267459 -0.70950264  0.70066651
## [241]  1.00134215  2.11352780 -0.05575784 -0.20758140 -2.32469687 -1.70617184
## [247] -2.78454904 -0.18042756 -1.31716520 -0.71516138 -0.71309205 -1.56092168
## [253] -0.44596508 -0.17042927  0.28518997  0.58688487  0.85486879  0.80260266
## [259]  0.77318877  0.34019578  0.87299986 -1.02635811  1.06502545  0.05616615
## [265]  0.20862475 -1.30253261 -1.20830410 -2.19631112 -0.99099370  1.07980433
## [271]  0.92405556  3.16320833  1.78124349  0.64779121 -1.35036514 -2.07845220
## [277] -1.32305313 -1.27809227  0.24410092  1.46611225  1.60229903  2.43127654
## [283]  2.59614799 -0.51087158  0.23979796 -1.62996428  0.42477237  0.46521931
## [289]  0.96451855 -1.95597236 -1.10360702 -2.31620671 -2.49021348 -2.73523686
## [295] -2.52266639 -0.96657601 -0.45523786
#Yt-3
yt_3_arma <- arma22[-c(288,289,300)]
yt_3_arma
##   [1]  0.06795477 -0.73270762  0.29534872 -0.88177243 -0.40494262 -1.81814223
##   [7] -2.63974439 -3.07358274 -2.71804095 -0.71635658 -1.61516276  0.15764457
##  [13] -0.47266329  1.44725419  2.51482053  3.64981261  2.51808704  0.94646378
##  [19] -1.73007867 -1.96463282 -2.29104663 -0.97842919 -0.98485685  0.78966693
##  [25]  0.32630064 -1.01519362 -0.68344715 -0.24220047 -0.19974042 -0.31979622
##  [31] -0.65860929  0.35018410  1.55062920  1.41188175  1.42666841  0.38973575
##  [37]  0.37200962  1.89051914  0.67059914  0.39926045 -2.05092604 -1.31421244
##  [43] -2.78184816 -0.96490651 -1.90637179 -1.01510832 -0.16831790  0.05284366
##  [49]  1.04785331  1.99941115 -0.43399489 -1.38465073 -3.25854344 -2.91053917
##  [55] -1.76146875  0.77132686  1.66259968  2.88184263  0.21059943 -0.37362893
##  [61] -2.17441288 -1.19599837 -1.30894285  0.91325166  1.90309705  3.17119697
##  [67]  2.87791790  2.00341061  1.09212683  1.91294317  2.58804162  3.64831854
##  [73]  3.84743593  3.69994307  4.04401256  1.44729195  1.38058144 -0.99201821
##  [79] -0.89626703 -0.67820990  0.73087800 -1.14706567 -0.95979023 -2.28773374
##  [85] -0.24989283  1.59612400  2.88040043  3.40185649  2.50481229  2.54370604
##  [91]  0.89249915  1.09894149  0.10822216 -0.90252578 -0.53864078 -1.03624384
##  [97] -0.57577877 -0.67681618 -1.74513073  0.67628703  0.21038958  2.81161890
## [103]  2.22238345  2.32035776  2.37308350  2.50952306  1.47892482  1.47543711
## [109]  2.06517091  2.91325997  4.12070753  1.08129055  1.34265399 -0.03034826
## [115]  1.58161673  1.66842633  2.58216181  1.59036645  2.16766846  1.10571250
## [121]  0.92123175 -0.44436437  0.91812334  1.72636619  0.54817175 -0.19740926
## [127] -1.54665694  0.03626248  0.16167768 -0.04133858 -1.18947866 -3.89570896
## [133] -4.79057199 -5.77699246 -4.60217289 -4.88761164 -3.98554798 -3.03872271
## [139] -2.80998811 -1.44132266 -2.17291500 -2.40676588 -2.84347224 -2.32878333
## [145] -3.01154797 -1.82230200 -1.69734749 -0.47155171  0.85442493  1.03733790
## [151]  0.60693501 -0.15610918 -1.01559798 -1.95738330 -1.64614024 -1.50531770
## [157] -0.66186877 -1.00750139 -0.22500658 -0.41753690  1.46537894  1.84696103
## [163]  3.05104849  1.14862156  0.79741988  0.88564357  0.25584872 -0.52801495
## [169] -0.63772209 -0.65327301  0.94384513  1.26127308  0.05832024  0.43588999
## [175] -2.66514227 -1.52240584 -1.97469214 -2.09330772 -1.60977783 -2.89279610
## [181] -2.55997257 -2.53149694 -2.15291713 -2.80010949 -1.11754905 -1.74508690
## [187] -0.93427842 -1.82930492  0.76478285 -0.37012447 -1.14499624 -2.41457013
## [193] -2.29506360 -1.87158883 -2.26566828 -4.00425945 -2.41131053 -4.07193819
## [199] -2.76653027 -4.48958572 -2.35194592 -1.16855276  0.05553665  0.72921129
## [205]  0.41890750  0.12189364  0.62374580  0.85113904  2.78306741  2.84234571
## [211]  4.55635930  3.23028105  2.88841993  2.21274152  2.07295624  0.84317889
## [217]  0.76793337  0.71050188 -1.00180768 -0.92098902 -2.11086345 -2.52248045
## [223] -3.76711115 -2.87728783 -3.08165719 -0.56416149 -1.37296037 -0.29866717
## [229] -0.99486310  0.83658518  0.44637035 -0.24053062 -1.53720361 -0.87694665
## [235]  0.49538436  0.42296975  1.23669465  0.77650740  0.05085706  0.23560050
## [241] -2.26267459 -0.70950264  0.70066651  1.00134215  2.11352780 -0.05575784
## [247] -0.20758140 -2.32469687 -1.70617184 -2.78454904 -0.18042756 -1.31716520
## [253] -0.71516138 -0.71309205 -1.56092168 -0.44596508 -0.17042927  0.28518997
## [259]  0.58688487  0.85486879  0.80260266  0.77318877  0.34019578  0.87299986
## [265] -1.02635811  1.06502545  0.05616615  0.20862475 -1.30253261 -1.20830410
## [271] -2.19631112 -0.99099370  1.07980433  0.92405556  3.16320833  1.78124349
## [277]  0.64779121 -1.35036514 -2.07845220 -1.32305313 -1.27809227  0.24410092
## [283]  1.46611225  1.60229903  2.43127654  2.59614799 -0.51087158  0.42477237
## [289]  0.46521931  0.96451855 -1.95597236 -1.10360702 -2.31620671 -2.49021348
## [295] -2.73523686 -2.52266639 -0.96657601
plot(y=yt_arma3,x=yt_3_arma)

Berdasarkan scatterplot tersebut, terlihat bahwa terdapat hubungan positif yang lemah antara \(Y_t\) dengan \(Y_{t-1}\). Hal ini sesuai dengan teori yang ada

cor(yt_arma3,yt_3_arma)
## [1] 0.4003797