White Noise

set.seed(1002)
wn <- rnorm(300)
ts.plot(wn)

Dapat terlihat bahwa white noise tidak memiliki autokorelasi dari ACF. Perhatikan bahwa lag ke-0 adalah korelasi observasi ke-t dengan dirinya sendiri. Nilai korelasi tersebut pasti 1. Sebagai alternatif, lag pertama di plot ACF dapat ditetapkan sebagai 1 (alih-alih 0) dengan menambahkan argumen xlim(1, lag akhir). Plot tersebut dapat disandingkan bersamaan dengan membuat matriks \(1 \times 2\) dengan par(mfrow = c(1,2)).

par(mfrow = c(1, 2)) 
acf(wn)
acf(wn, xlim = c(1, 20))

Proses MA

Proses MA dapat dituliskan sebagai berikut:

\[ y_{t} = c + e_t + \theta_{1}e_{t-1} + \theta_{2}e_{t-2} + \dots + \theta_{q}e_{t-q} = c+{e_t+\sum_{i=1}^p \theta_ie_{t-i}} \] Terlihat bahwa \(e_t\), atau white noise, berperan penting dalam pembangkitan proses MA.

Pembangkitan Proses MA(2)

Akan dicoba membangkitkan proses MA paling sederhana, yaitu MA(2) dengan \(\theta_1 = 0.4\) dan \(\theta_2 = 0.6\)sebanyak 300 observasi dan \(c=0\). Karena diperlukan satu nilai awal untuk \(e_{t-2}\), masukkan nilai pertama white noise sebagai nilai awal tersebut.

set.seed(1002)
ma<- wn[c(1,2)]
ma
## [1] -0.1382882  0.2846285

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

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

set.seed(1002)
for(i in 3:300){
   ma[i] <- wn[i] + 0.4 * wn[i - 1] +  0.6 * wn[i - 2] 
}
ma
##   [1] -0.1382881842  0.2846285351 -0.2913725396  1.9471847822  0.2039450696
##   [6]  1.2931078276  0.0480891236 -1.3443863362 -0.2071210815  0.6596565425
##  [11]  0.2030366571  1.2024391609  0.7593035708  0.7033449886  1.9403469147
##  [16]  0.3925484551  0.6674976688 -0.3446283632  1.9084081647  0.3019882409
##  [21]  0.0756044605 -1.2845018549 -0.7347703151  1.1684735578 -0.7022092018
##  [26]  0.8164260215 -0.0005709686  1.9069194491  1.2030284748  0.0707856096
##  [31] -1.3810693189 -1.6142778433 -0.6245852823 -0.8725018478  0.2341620404
##  [36] -0.6939341378 -0.4827299922  1.3884701207 -0.9152117468  0.0387632465
##  [41] -1.6400317856  1.0005821561  0.7046606538  0.1053001179 -0.7675444479
##  [46] -0.3746294673  0.0867119079  0.0624423465  1.0284534633  0.5889407161
##  [51]  2.0826487470  0.8222595799  0.9659892717  1.3617771939  0.2808865606
##  [56]  0.2927791590 -1.2425251238 -0.6145897515  0.2305059778 -0.0008796766
##  [61] -0.3538948232 -1.3370825139 -1.0768203043 -0.8889290122  0.7482329302
##  [66] -0.4956215950  0.8665308492  0.6985899983  0.5059316503  3.4378466046
##  [71]  1.1085522764  0.6293708571 -0.3546625549 -0.6117615042  1.0054429401
##  [76]  2.0239920538  0.9722914878  1.7884856065 -0.9500941082 -1.2890124481
##  [81]  0.1920572179 -0.3562315333  1.9317168346  0.0930827747  0.7722635840
##  [86] -1.3645812477  1.1925189739 -0.1266541905  1.9254811223  0.3148387204
##  [91] -0.4656714742 -0.5976814383 -0.1252779443  2.0231193708  2.4625345920
##  [96]  2.1910596217  1.4214113024  0.8766225940  0.9267589084 -0.8232050274
## [101] -1.6264722750 -2.0437599459  0.0593472813 -0.4766026587 -0.4274172270
## [106]  0.5865156735 -2.5723728557  0.2018284826 -1.3864904483 -0.2671476548
## [111] -0.1622579378 -1.8886213965  0.0963531485 -0.5773190694  1.9487790570
## [116]  1.3912223790  1.6739861739  0.8671740946  0.9379216612 -1.2430639940
## [121] -1.2425258378 -3.7908666936  0.1054106417 -1.0097051137 -0.1444730816
## [126] -1.3360990732 -0.7395354999 -0.5234724890  1.1519528340 -0.7542851340
## [131]  0.5545346831  1.0773612788  2.1864016426  1.3575846676 -0.0603187191
## [136] -1.3182072883 -1.4831605057 -2.2369214890 -1.5564018418 -1.5200332576
## [141]  0.5518822885 -0.5403428041 -1.0113170122 -0.4044165025  0.3765462648
## [146] -0.5139685156  0.2227773739 -0.8298204850  0.1493382246  0.4209347510
## [151]  1.5354375656  1.5069008021  1.4404986178 -1.1516092916 -0.2291156817
## [156] -1.8238967982 -1.2169569496 -0.3471614692  0.8206307081  1.2674616742
## [161]  2.3185736810 -0.6890438106  0.2954115052 -0.0694363757  0.8270306299
## [166]  1.2112715185 -1.3932545390 -0.6249472403 -0.5380299092 -0.0956441836
## [171]  0.0714389431 -1.5618061241  0.0605293549 -0.5223492304  0.2232705480
## [176]  1.1938956098  0.3911999599  1.4792286808  0.5822047003  1.5292924790
## [181]  0.9925623705  2.2805912681  0.6918573713  1.2662349029 -0.6728839038
## [186]  0.5485919729  1.3758753904  1.2765154339  1.6191261090 -0.5721040622
## [191]  0.6914655381 -2.4633202551 -1.7141729685 -4.3145435835 -2.1094561668
## [196] -1.1148026417  0.5188166714  0.4280945822  0.6413359989  1.7023184786
## [201]  1.5466777022  2.4972648386  1.8464181654  0.4783098581  0.2668014391
## [206]  0.6609506233 -2.6271836829 -1.0271632093  0.7188278491 -1.4071705984
## [211]  2.5029596596 -2.1767000016  0.2261918704 -1.3393432359  0.7714065328
## [216]  0.4177407565 -1.8540075065 -1.2359973739 -1.3729928044 -0.6071069445
## [221]  0.2325083951 -0.8897303942  0.7797076467 -0.5835862514  0.3875298318
## [226] -1.5752881050 -1.6394575680 -0.6532492389 -0.3842339593  0.9968224736
## [231] -0.8086459427  0.8868701042 -0.3780727327  2.5758449791  1.7148315670
## [236]  2.7324272009  0.8332397531  1.0009507824  1.9685409632  2.3697016706
## [241]  1.3812051877  2.6212638095  1.9812571526  0.7688579152  0.2944286504
## [246]  0.2373890442  0.0905573537  0.1444155868  0.2068117180 -0.1686321278
## [251]  0.5768913360  0.6174192653  0.2471049651  2.1248481028 -0.8621236553
## [256]  1.8551046478 -0.7396138335  0.9953012828  1.1706687453 -0.2612307520
## [261]  1.0922108791 -1.6247741546 -0.0303707421 -2.2773534114  0.2039318009
## [266] -0.9852282256 -0.8710586780 -0.3454705217 -0.7734511977 -0.8588926361
## [271]  0.5258935590 -0.6277777871  0.1381115635  0.3688323198  0.5049496838
## [276]  0.1912585536 -0.4319266648 -1.3755588492 -0.3239822272 -0.4062433845
## [281]  0.7200298762  0.1349736491 -0.3088818566 -0.2619393812 -0.9094469352
## [286] -0.6455037033  0.4139233572  1.2062168717  2.4547921170  1.4016281232
## [291]  0.0525150278 -0.2901311561  0.0027978397  0.5333436989  0.5582367761
## [296]  0.1770709978 -0.0980639856  0.3733346775 -1.7322856400  0.7996808082

Selain menggunakan cara di atas, pembangkitan proses MA(2) dapat dilakukan dengan fungsi arima.sim() sebagai berikut.

set.seed(1002)
ma2 <- arima.sim(list(order=c(0,0,2), ma=c(0.4,0.6)), n=300)
ma2
## Time Series:
## Start = 1 
## End = 300 
## Frequency = 1 
##   [1] -0.2913725396  1.9471847822  0.2039450696  1.2931078276  0.0480891236
##   [6] -1.3443863362 -0.2071210815  0.6596565425  0.2030366571  1.2024391609
##  [11]  0.7593035708  0.7033449886  1.9403469147  0.3925484551  0.6674976688
##  [16] -0.3446283632  1.9084081647  0.3019882409  0.0756044605 -1.2845018549
##  [21] -0.7347703151  1.1684735578 -0.7022092018  0.8164260215 -0.0005709686
##  [26]  1.9069194491  1.2030284748  0.0707856096 -1.3810693189 -1.6142778433
##  [31] -0.6245852823 -0.8725018478  0.2341620404 -0.6939341378 -0.4827299922
##  [36]  1.3884701207 -0.9152117468  0.0387632465 -1.6400317856  1.0005821561
##  [41]  0.7046606538  0.1053001179 -0.7675444479 -0.3746294673  0.0867119079
##  [46]  0.0624423465  1.0284534633  0.5889407161  2.0826487470  0.8222595799
##  [51]  0.9659892717  1.3617771939  0.2808865606  0.2927791590 -1.2425251238
##  [56] -0.6145897515  0.2305059778 -0.0008796766 -0.3538948232 -1.3370825139
##  [61] -1.0768203043 -0.8889290122  0.7482329302 -0.4956215950  0.8665308492
##  [66]  0.6985899983  0.5059316503  3.4378466046  1.1085522764  0.6293708571
##  [71] -0.3546625549 -0.6117615042  1.0054429401  2.0239920538  0.9722914878
##  [76]  1.7884856065 -0.9500941082 -1.2890124481  0.1920572179 -0.3562315333
##  [81]  1.9317168346  0.0930827747  0.7722635840 -1.3645812477  1.1925189739
##  [86] -0.1266541905  1.9254811223  0.3148387204 -0.4656714742 -0.5976814383
##  [91] -0.1252779443  2.0231193708  2.4625345920  2.1910596217  1.4214113024
##  [96]  0.8766225940  0.9267589084 -0.8232050274 -1.6264722750 -2.0437599459
## [101]  0.0593472813 -0.4766026587 -0.4274172270  0.5865156735 -2.5723728557
## [106]  0.2018284826 -1.3864904483 -0.2671476548 -0.1622579378 -1.8886213965
## [111]  0.0963531485 -0.5773190694  1.9487790570  1.3912223790  1.6739861739
## [116]  0.8671740946  0.9379216612 -1.2430639940 -1.2425258378 -3.7908666936
## [121]  0.1054106417 -1.0097051137 -0.1444730816 -1.3360990732 -0.7395354999
## [126] -0.5234724890  1.1519528340 -0.7542851340  0.5545346831  1.0773612788
## [131]  2.1864016426  1.3575846676 -0.0603187191 -1.3182072883 -1.4831605057
## [136] -2.2369214890 -1.5564018418 -1.5200332576  0.5518822885 -0.5403428041
## [141] -1.0113170122 -0.4044165025  0.3765462648 -0.5139685156  0.2227773739
## [146] -0.8298204850  0.1493382246  0.4209347510  1.5354375656  1.5069008021
## [151]  1.4404986178 -1.1516092916 -0.2291156817 -1.8238967982 -1.2169569496
## [156] -0.3471614692  0.8206307081  1.2674616742  2.3185736810 -0.6890438106
## [161]  0.2954115052 -0.0694363757  0.8270306299  1.2112715185 -1.3932545390
## [166] -0.6249472403 -0.5380299092 -0.0956441836  0.0714389431 -1.5618061241
## [171]  0.0605293549 -0.5223492304  0.2232705480  1.1938956098  0.3911999599
## [176]  1.4792286808  0.5822047003  1.5292924790  0.9925623705  2.2805912681
## [181]  0.6918573713  1.2662349029 -0.6728839038  0.5485919729  1.3758753904
## [186]  1.2765154339  1.6191261090 -0.5721040622  0.6914655381 -2.4633202551
## [191] -1.7141729685 -4.3145435835 -2.1094561668 -1.1148026417  0.5188166714
## [196]  0.4280945822  0.6413359989  1.7023184786  1.5466777022  2.4972648386
## [201]  1.8464181654  0.4783098581  0.2668014391  0.6609506233 -2.6271836829
## [206] -1.0271632093  0.7188278491 -1.4071705984  2.5029596596 -2.1767000016
## [211]  0.2261918704 -1.3393432359  0.7714065328  0.4177407565 -1.8540075065
## [216] -1.2359973739 -1.3729928044 -0.6071069445  0.2325083951 -0.8897303942
## [221]  0.7797076467 -0.5835862514  0.3875298318 -1.5752881050 -1.6394575680
## [226] -0.6532492389 -0.3842339593  0.9968224736 -0.8086459427  0.8868701042
## [231] -0.3780727327  2.5758449791  1.7148315670  2.7324272009  0.8332397531
## [236]  1.0009507824  1.9685409632  2.3697016706  1.3812051877  2.6212638095
## [241]  1.9812571526  0.7688579152  0.2944286504  0.2373890442  0.0905573537
## [246]  0.1444155868  0.2068117180 -0.1686321278  0.5768913360  0.6174192653
## [251]  0.2471049651  2.1248481028 -0.8621236553  1.8551046478 -0.7396138335
## [256]  0.9953012828  1.1706687453 -0.2612307520  1.0922108791 -1.6247741546
## [261] -0.0303707421 -2.2773534114  0.2039318009 -0.9852282256 -0.8710586780
## [266] -0.3454705217 -0.7734511977 -0.8588926361  0.5258935590 -0.6277777871
## [271]  0.1381115635  0.3688323198  0.5049496838  0.1912585536 -0.4319266648
## [276] -1.3755588492 -0.3239822272 -0.4062433845  0.7200298762  0.1349736491
## [281] -0.3088818566 -0.2619393812 -0.9094469352 -0.6455037033  0.4139233572
## [286]  1.2062168717  2.4547921170  1.4016281232  0.0525150278 -0.2901311561
## [291]  0.0027978397  0.5333436989  0.5582367761  0.1770709978 -0.0980639856
## [296]  0.3733346775 -1.7322856400  0.7996808082 -1.0146825427  2.1128443720

Karakteristik MA(2)

Plot Time Series

ts.plot(ma2)

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

Plot ACF

acf(ma2,lag.max = 20)

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

Plot PACF

pacf(ma2)

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

Plot EACF

TSA::eacf(ma2)
## 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 x o x x o o o o o  o  o  o 
## 5 x x x x x x o o o o o  o  o  o 
## 6 x x x x o o x x o o o  o  o  o 
## 7 x x x x x o o x 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(2)

Scatterplot Antar Lag

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

#Yt
yt_ma2 <- ma2[-1]
yt_ma2
##   [1]  1.9471847822  0.2039450696  1.2931078276  0.0480891236 -1.3443863362
##   [6] -0.2071210815  0.6596565425  0.2030366571  1.2024391609  0.7593035708
##  [11]  0.7033449886  1.9403469147  0.3925484551  0.6674976688 -0.3446283632
##  [16]  1.9084081647  0.3019882409  0.0756044605 -1.2845018549 -0.7347703151
##  [21]  1.1684735578 -0.7022092018  0.8164260215 -0.0005709686  1.9069194491
##  [26]  1.2030284748  0.0707856096 -1.3810693189 -1.6142778433 -0.6245852823
##  [31] -0.8725018478  0.2341620404 -0.6939341378 -0.4827299922  1.3884701207
##  [36] -0.9152117468  0.0387632465 -1.6400317856  1.0005821561  0.7046606538
##  [41]  0.1053001179 -0.7675444479 -0.3746294673  0.0867119079  0.0624423465
##  [46]  1.0284534633  0.5889407161  2.0826487470  0.8222595799  0.9659892717
##  [51]  1.3617771939  0.2808865606  0.2927791590 -1.2425251238 -0.6145897515
##  [56]  0.2305059778 -0.0008796766 -0.3538948232 -1.3370825139 -1.0768203043
##  [61] -0.8889290122  0.7482329302 -0.4956215950  0.8665308492  0.6985899983
##  [66]  0.5059316503  3.4378466046  1.1085522764  0.6293708571 -0.3546625549
##  [71] -0.6117615042  1.0054429401  2.0239920538  0.9722914878  1.7884856065
##  [76] -0.9500941082 -1.2890124481  0.1920572179 -0.3562315333  1.9317168346
##  [81]  0.0930827747  0.7722635840 -1.3645812477  1.1925189739 -0.1266541905
##  [86]  1.9254811223  0.3148387204 -0.4656714742 -0.5976814383 -0.1252779443
##  [91]  2.0231193708  2.4625345920  2.1910596217  1.4214113024  0.8766225940
##  [96]  0.9267589084 -0.8232050274 -1.6264722750 -2.0437599459  0.0593472813
## [101] -0.4766026587 -0.4274172270  0.5865156735 -2.5723728557  0.2018284826
## [106] -1.3864904483 -0.2671476548 -0.1622579378 -1.8886213965  0.0963531485
## [111] -0.5773190694  1.9487790570  1.3912223790  1.6739861739  0.8671740946
## [116]  0.9379216612 -1.2430639940 -1.2425258378 -3.7908666936  0.1054106417
## [121] -1.0097051137 -0.1444730816 -1.3360990732 -0.7395354999 -0.5234724890
## [126]  1.1519528340 -0.7542851340  0.5545346831  1.0773612788  2.1864016426
## [131]  1.3575846676 -0.0603187191 -1.3182072883 -1.4831605057 -2.2369214890
## [136] -1.5564018418 -1.5200332576  0.5518822885 -0.5403428041 -1.0113170122
## [141] -0.4044165025  0.3765462648 -0.5139685156  0.2227773739 -0.8298204850
## [146]  0.1493382246  0.4209347510  1.5354375656  1.5069008021  1.4404986178
## [151] -1.1516092916 -0.2291156817 -1.8238967982 -1.2169569496 -0.3471614692
## [156]  0.8206307081  1.2674616742  2.3185736810 -0.6890438106  0.2954115052
## [161] -0.0694363757  0.8270306299  1.2112715185 -1.3932545390 -0.6249472403
## [166] -0.5380299092 -0.0956441836  0.0714389431 -1.5618061241  0.0605293549
## [171] -0.5223492304  0.2232705480  1.1938956098  0.3911999599  1.4792286808
## [176]  0.5822047003  1.5292924790  0.9925623705  2.2805912681  0.6918573713
## [181]  1.2662349029 -0.6728839038  0.5485919729  1.3758753904  1.2765154339
## [186]  1.6191261090 -0.5721040622  0.6914655381 -2.4633202551 -1.7141729685
## [191] -4.3145435835 -2.1094561668 -1.1148026417  0.5188166714  0.4280945822
## [196]  0.6413359989  1.7023184786  1.5466777022  2.4972648386  1.8464181654
## [201]  0.4783098581  0.2668014391  0.6609506233 -2.6271836829 -1.0271632093
## [206]  0.7188278491 -1.4071705984  2.5029596596 -2.1767000016  0.2261918704
## [211] -1.3393432359  0.7714065328  0.4177407565 -1.8540075065 -1.2359973739
## [216] -1.3729928044 -0.6071069445  0.2325083951 -0.8897303942  0.7797076467
## [221] -0.5835862514  0.3875298318 -1.5752881050 -1.6394575680 -0.6532492389
## [226] -0.3842339593  0.9968224736 -0.8086459427  0.8868701042 -0.3780727327
## [231]  2.5758449791  1.7148315670  2.7324272009  0.8332397531  1.0009507824
## [236]  1.9685409632  2.3697016706  1.3812051877  2.6212638095  1.9812571526
## [241]  0.7688579152  0.2944286504  0.2373890442  0.0905573537  0.1444155868
## [246]  0.2068117180 -0.1686321278  0.5768913360  0.6174192653  0.2471049651
## [251]  2.1248481028 -0.8621236553  1.8551046478 -0.7396138335  0.9953012828
## [256]  1.1706687453 -0.2612307520  1.0922108791 -1.6247741546 -0.0303707421
## [261] -2.2773534114  0.2039318009 -0.9852282256 -0.8710586780 -0.3454705217
## [266] -0.7734511977 -0.8588926361  0.5258935590 -0.6277777871  0.1381115635
## [271]  0.3688323198  0.5049496838  0.1912585536 -0.4319266648 -1.3755588492
## [276] -0.3239822272 -0.4062433845  0.7200298762  0.1349736491 -0.3088818566
## [281] -0.2619393812 -0.9094469352 -0.6455037033  0.4139233572  1.2062168717
## [286]  2.4547921170  1.4016281232  0.0525150278 -0.2901311561  0.0027978397
## [291]  0.5333436989  0.5582367761  0.1770709978 -0.0980639856  0.3733346775
## [296] -1.7322856400  0.7996808082 -1.0146825427  2.1128443720
#Yt-1
yt_1_ma2 <- ma2[-300]
yt_1_ma2
##   [1] -0.2913725396  1.9471847822  0.2039450696  1.2931078276  0.0480891236
##   [6] -1.3443863362 -0.2071210815  0.6596565425  0.2030366571  1.2024391609
##  [11]  0.7593035708  0.7033449886  1.9403469147  0.3925484551  0.6674976688
##  [16] -0.3446283632  1.9084081647  0.3019882409  0.0756044605 -1.2845018549
##  [21] -0.7347703151  1.1684735578 -0.7022092018  0.8164260215 -0.0005709686
##  [26]  1.9069194491  1.2030284748  0.0707856096 -1.3810693189 -1.6142778433
##  [31] -0.6245852823 -0.8725018478  0.2341620404 -0.6939341378 -0.4827299922
##  [36]  1.3884701207 -0.9152117468  0.0387632465 -1.6400317856  1.0005821561
##  [41]  0.7046606538  0.1053001179 -0.7675444479 -0.3746294673  0.0867119079
##  [46]  0.0624423465  1.0284534633  0.5889407161  2.0826487470  0.8222595799
##  [51]  0.9659892717  1.3617771939  0.2808865606  0.2927791590 -1.2425251238
##  [56] -0.6145897515  0.2305059778 -0.0008796766 -0.3538948232 -1.3370825139
##  [61] -1.0768203043 -0.8889290122  0.7482329302 -0.4956215950  0.8665308492
##  [66]  0.6985899983  0.5059316503  3.4378466046  1.1085522764  0.6293708571
##  [71] -0.3546625549 -0.6117615042  1.0054429401  2.0239920538  0.9722914878
##  [76]  1.7884856065 -0.9500941082 -1.2890124481  0.1920572179 -0.3562315333
##  [81]  1.9317168346  0.0930827747  0.7722635840 -1.3645812477  1.1925189739
##  [86] -0.1266541905  1.9254811223  0.3148387204 -0.4656714742 -0.5976814383
##  [91] -0.1252779443  2.0231193708  2.4625345920  2.1910596217  1.4214113024
##  [96]  0.8766225940  0.9267589084 -0.8232050274 -1.6264722750 -2.0437599459
## [101]  0.0593472813 -0.4766026587 -0.4274172270  0.5865156735 -2.5723728557
## [106]  0.2018284826 -1.3864904483 -0.2671476548 -0.1622579378 -1.8886213965
## [111]  0.0963531485 -0.5773190694  1.9487790570  1.3912223790  1.6739861739
## [116]  0.8671740946  0.9379216612 -1.2430639940 -1.2425258378 -3.7908666936
## [121]  0.1054106417 -1.0097051137 -0.1444730816 -1.3360990732 -0.7395354999
## [126] -0.5234724890  1.1519528340 -0.7542851340  0.5545346831  1.0773612788
## [131]  2.1864016426  1.3575846676 -0.0603187191 -1.3182072883 -1.4831605057
## [136] -2.2369214890 -1.5564018418 -1.5200332576  0.5518822885 -0.5403428041
## [141] -1.0113170122 -0.4044165025  0.3765462648 -0.5139685156  0.2227773739
## [146] -0.8298204850  0.1493382246  0.4209347510  1.5354375656  1.5069008021
## [151]  1.4404986178 -1.1516092916 -0.2291156817 -1.8238967982 -1.2169569496
## [156] -0.3471614692  0.8206307081  1.2674616742  2.3185736810 -0.6890438106
## [161]  0.2954115052 -0.0694363757  0.8270306299  1.2112715185 -1.3932545390
## [166] -0.6249472403 -0.5380299092 -0.0956441836  0.0714389431 -1.5618061241
## [171]  0.0605293549 -0.5223492304  0.2232705480  1.1938956098  0.3911999599
## [176]  1.4792286808  0.5822047003  1.5292924790  0.9925623705  2.2805912681
## [181]  0.6918573713  1.2662349029 -0.6728839038  0.5485919729  1.3758753904
## [186]  1.2765154339  1.6191261090 -0.5721040622  0.6914655381 -2.4633202551
## [191] -1.7141729685 -4.3145435835 -2.1094561668 -1.1148026417  0.5188166714
## [196]  0.4280945822  0.6413359989  1.7023184786  1.5466777022  2.4972648386
## [201]  1.8464181654  0.4783098581  0.2668014391  0.6609506233 -2.6271836829
## [206] -1.0271632093  0.7188278491 -1.4071705984  2.5029596596 -2.1767000016
## [211]  0.2261918704 -1.3393432359  0.7714065328  0.4177407565 -1.8540075065
## [216] -1.2359973739 -1.3729928044 -0.6071069445  0.2325083951 -0.8897303942
## [221]  0.7797076467 -0.5835862514  0.3875298318 -1.5752881050 -1.6394575680
## [226] -0.6532492389 -0.3842339593  0.9968224736 -0.8086459427  0.8868701042
## [231] -0.3780727327  2.5758449791  1.7148315670  2.7324272009  0.8332397531
## [236]  1.0009507824  1.9685409632  2.3697016706  1.3812051877  2.6212638095
## [241]  1.9812571526  0.7688579152  0.2944286504  0.2373890442  0.0905573537
## [246]  0.1444155868  0.2068117180 -0.1686321278  0.5768913360  0.6174192653
## [251]  0.2471049651  2.1248481028 -0.8621236553  1.8551046478 -0.7396138335
## [256]  0.9953012828  1.1706687453 -0.2612307520  1.0922108791 -1.6247741546
## [261] -0.0303707421 -2.2773534114  0.2039318009 -0.9852282256 -0.8710586780
## [266] -0.3454705217 -0.7734511977 -0.8588926361  0.5258935590 -0.6277777871
## [271]  0.1381115635  0.3688323198  0.5049496838  0.1912585536 -0.4319266648
## [276] -1.3755588492 -0.3239822272 -0.4062433845  0.7200298762  0.1349736491
## [281] -0.3088818566 -0.2619393812 -0.9094469352 -0.6455037033  0.4139233572
## [286]  1.2062168717  2.4547921170  1.4016281232  0.0525150278 -0.2901311561
## [291]  0.0027978397  0.5333436989  0.5582367761  0.1770709978 -0.0980639856
## [296]  0.3733346775 -1.7322856400  0.7996808082 -1.0146825427
cor(yt_ma2,yt_1_ma2)
## [1] 0.3298152

Korelasi antara \(Y_t\) dengan \(Y_{t-1}\) hasil simulasi yaitu 0.3298152

plot(y=yt_ma2,x=yt_1_ma2)

Berdasarkan scatterplot tersebut, terlihat bahwa cenderung terdapat hubungan positif lemah antara \(Y_t\) dengan \(Y_{t-1}\).

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

#Yt
yt_ma2 <- ma2[-c(1,2)]
yt_ma2
##   [1]  0.2039450696  1.2931078276  0.0480891236 -1.3443863362 -0.2071210815
##   [6]  0.6596565425  0.2030366571  1.2024391609  0.7593035708  0.7033449886
##  [11]  1.9403469147  0.3925484551  0.6674976688 -0.3446283632  1.9084081647
##  [16]  0.3019882409  0.0756044605 -1.2845018549 -0.7347703151  1.1684735578
##  [21] -0.7022092018  0.8164260215 -0.0005709686  1.9069194491  1.2030284748
##  [26]  0.0707856096 -1.3810693189 -1.6142778433 -0.6245852823 -0.8725018478
##  [31]  0.2341620404 -0.6939341378 -0.4827299922  1.3884701207 -0.9152117468
##  [36]  0.0387632465 -1.6400317856  1.0005821561  0.7046606538  0.1053001179
##  [41] -0.7675444479 -0.3746294673  0.0867119079  0.0624423465  1.0284534633
##  [46]  0.5889407161  2.0826487470  0.8222595799  0.9659892717  1.3617771939
##  [51]  0.2808865606  0.2927791590 -1.2425251238 -0.6145897515  0.2305059778
##  [56] -0.0008796766 -0.3538948232 -1.3370825139 -1.0768203043 -0.8889290122
##  [61]  0.7482329302 -0.4956215950  0.8665308492  0.6985899983  0.5059316503
##  [66]  3.4378466046  1.1085522764  0.6293708571 -0.3546625549 -0.6117615042
##  [71]  1.0054429401  2.0239920538  0.9722914878  1.7884856065 -0.9500941082
##  [76] -1.2890124481  0.1920572179 -0.3562315333  1.9317168346  0.0930827747
##  [81]  0.7722635840 -1.3645812477  1.1925189739 -0.1266541905  1.9254811223
##  [86]  0.3148387204 -0.4656714742 -0.5976814383 -0.1252779443  2.0231193708
##  [91]  2.4625345920  2.1910596217  1.4214113024  0.8766225940  0.9267589084
##  [96] -0.8232050274 -1.6264722750 -2.0437599459  0.0593472813 -0.4766026587
## [101] -0.4274172270  0.5865156735 -2.5723728557  0.2018284826 -1.3864904483
## [106] -0.2671476548 -0.1622579378 -1.8886213965  0.0963531485 -0.5773190694
## [111]  1.9487790570  1.3912223790  1.6739861739  0.8671740946  0.9379216612
## [116] -1.2430639940 -1.2425258378 -3.7908666936  0.1054106417 -1.0097051137
## [121] -0.1444730816 -1.3360990732 -0.7395354999 -0.5234724890  1.1519528340
## [126] -0.7542851340  0.5545346831  1.0773612788  2.1864016426  1.3575846676
## [131] -0.0603187191 -1.3182072883 -1.4831605057 -2.2369214890 -1.5564018418
## [136] -1.5200332576  0.5518822885 -0.5403428041 -1.0113170122 -0.4044165025
## [141]  0.3765462648 -0.5139685156  0.2227773739 -0.8298204850  0.1493382246
## [146]  0.4209347510  1.5354375656  1.5069008021  1.4404986178 -1.1516092916
## [151] -0.2291156817 -1.8238967982 -1.2169569496 -0.3471614692  0.8206307081
## [156]  1.2674616742  2.3185736810 -0.6890438106  0.2954115052 -0.0694363757
## [161]  0.8270306299  1.2112715185 -1.3932545390 -0.6249472403 -0.5380299092
## [166] -0.0956441836  0.0714389431 -1.5618061241  0.0605293549 -0.5223492304
## [171]  0.2232705480  1.1938956098  0.3911999599  1.4792286808  0.5822047003
## [176]  1.5292924790  0.9925623705  2.2805912681  0.6918573713  1.2662349029
## [181] -0.6728839038  0.5485919729  1.3758753904  1.2765154339  1.6191261090
## [186] -0.5721040622  0.6914655381 -2.4633202551 -1.7141729685 -4.3145435835
## [191] -2.1094561668 -1.1148026417  0.5188166714  0.4280945822  0.6413359989
## [196]  1.7023184786  1.5466777022  2.4972648386  1.8464181654  0.4783098581
## [201]  0.2668014391  0.6609506233 -2.6271836829 -1.0271632093  0.7188278491
## [206] -1.4071705984  2.5029596596 -2.1767000016  0.2261918704 -1.3393432359
## [211]  0.7714065328  0.4177407565 -1.8540075065 -1.2359973739 -1.3729928044
## [216] -0.6071069445  0.2325083951 -0.8897303942  0.7797076467 -0.5835862514
## [221]  0.3875298318 -1.5752881050 -1.6394575680 -0.6532492389 -0.3842339593
## [226]  0.9968224736 -0.8086459427  0.8868701042 -0.3780727327  2.5758449791
## [231]  1.7148315670  2.7324272009  0.8332397531  1.0009507824  1.9685409632
## [236]  2.3697016706  1.3812051877  2.6212638095  1.9812571526  0.7688579152
## [241]  0.2944286504  0.2373890442  0.0905573537  0.1444155868  0.2068117180
## [246] -0.1686321278  0.5768913360  0.6174192653  0.2471049651  2.1248481028
## [251] -0.8621236553  1.8551046478 -0.7396138335  0.9953012828  1.1706687453
## [256] -0.2612307520  1.0922108791 -1.6247741546 -0.0303707421 -2.2773534114
## [261]  0.2039318009 -0.9852282256 -0.8710586780 -0.3454705217 -0.7734511977
## [266] -0.8588926361  0.5258935590 -0.6277777871  0.1381115635  0.3688323198
## [271]  0.5049496838  0.1912585536 -0.4319266648 -1.3755588492 -0.3239822272
## [276] -0.4062433845  0.7200298762  0.1349736491 -0.3088818566 -0.2619393812
## [281] -0.9094469352 -0.6455037033  0.4139233572  1.2062168717  2.4547921170
## [286]  1.4016281232  0.0525150278 -0.2901311561  0.0027978397  0.5333436989
## [291]  0.5582367761  0.1770709978 -0.0980639856  0.3733346775 -1.7322856400
## [296]  0.7996808082 -1.0146825427  2.1128443720
#Yt-2
yt_2_ma2 <- ma2[-c(299,300)]
yt_2_ma2
##   [1] -0.2913725396  1.9471847822  0.2039450696  1.2931078276  0.0480891236
##   [6] -1.3443863362 -0.2071210815  0.6596565425  0.2030366571  1.2024391609
##  [11]  0.7593035708  0.7033449886  1.9403469147  0.3925484551  0.6674976688
##  [16] -0.3446283632  1.9084081647  0.3019882409  0.0756044605 -1.2845018549
##  [21] -0.7347703151  1.1684735578 -0.7022092018  0.8164260215 -0.0005709686
##  [26]  1.9069194491  1.2030284748  0.0707856096 -1.3810693189 -1.6142778433
##  [31] -0.6245852823 -0.8725018478  0.2341620404 -0.6939341378 -0.4827299922
##  [36]  1.3884701207 -0.9152117468  0.0387632465 -1.6400317856  1.0005821561
##  [41]  0.7046606538  0.1053001179 -0.7675444479 -0.3746294673  0.0867119079
##  [46]  0.0624423465  1.0284534633  0.5889407161  2.0826487470  0.8222595799
##  [51]  0.9659892717  1.3617771939  0.2808865606  0.2927791590 -1.2425251238
##  [56] -0.6145897515  0.2305059778 -0.0008796766 -0.3538948232 -1.3370825139
##  [61] -1.0768203043 -0.8889290122  0.7482329302 -0.4956215950  0.8665308492
##  [66]  0.6985899983  0.5059316503  3.4378466046  1.1085522764  0.6293708571
##  [71] -0.3546625549 -0.6117615042  1.0054429401  2.0239920538  0.9722914878
##  [76]  1.7884856065 -0.9500941082 -1.2890124481  0.1920572179 -0.3562315333
##  [81]  1.9317168346  0.0930827747  0.7722635840 -1.3645812477  1.1925189739
##  [86] -0.1266541905  1.9254811223  0.3148387204 -0.4656714742 -0.5976814383
##  [91] -0.1252779443  2.0231193708  2.4625345920  2.1910596217  1.4214113024
##  [96]  0.8766225940  0.9267589084 -0.8232050274 -1.6264722750 -2.0437599459
## [101]  0.0593472813 -0.4766026587 -0.4274172270  0.5865156735 -2.5723728557
## [106]  0.2018284826 -1.3864904483 -0.2671476548 -0.1622579378 -1.8886213965
## [111]  0.0963531485 -0.5773190694  1.9487790570  1.3912223790  1.6739861739
## [116]  0.8671740946  0.9379216612 -1.2430639940 -1.2425258378 -3.7908666936
## [121]  0.1054106417 -1.0097051137 -0.1444730816 -1.3360990732 -0.7395354999
## [126] -0.5234724890  1.1519528340 -0.7542851340  0.5545346831  1.0773612788
## [131]  2.1864016426  1.3575846676 -0.0603187191 -1.3182072883 -1.4831605057
## [136] -2.2369214890 -1.5564018418 -1.5200332576  0.5518822885 -0.5403428041
## [141] -1.0113170122 -0.4044165025  0.3765462648 -0.5139685156  0.2227773739
## [146] -0.8298204850  0.1493382246  0.4209347510  1.5354375656  1.5069008021
## [151]  1.4404986178 -1.1516092916 -0.2291156817 -1.8238967982 -1.2169569496
## [156] -0.3471614692  0.8206307081  1.2674616742  2.3185736810 -0.6890438106
## [161]  0.2954115052 -0.0694363757  0.8270306299  1.2112715185 -1.3932545390
## [166] -0.6249472403 -0.5380299092 -0.0956441836  0.0714389431 -1.5618061241
## [171]  0.0605293549 -0.5223492304  0.2232705480  1.1938956098  0.3911999599
## [176]  1.4792286808  0.5822047003  1.5292924790  0.9925623705  2.2805912681
## [181]  0.6918573713  1.2662349029 -0.6728839038  0.5485919729  1.3758753904
## [186]  1.2765154339  1.6191261090 -0.5721040622  0.6914655381 -2.4633202551
## [191] -1.7141729685 -4.3145435835 -2.1094561668 -1.1148026417  0.5188166714
## [196]  0.4280945822  0.6413359989  1.7023184786  1.5466777022  2.4972648386
## [201]  1.8464181654  0.4783098581  0.2668014391  0.6609506233 -2.6271836829
## [206] -1.0271632093  0.7188278491 -1.4071705984  2.5029596596 -2.1767000016
## [211]  0.2261918704 -1.3393432359  0.7714065328  0.4177407565 -1.8540075065
## [216] -1.2359973739 -1.3729928044 -0.6071069445  0.2325083951 -0.8897303942
## [221]  0.7797076467 -0.5835862514  0.3875298318 -1.5752881050 -1.6394575680
## [226] -0.6532492389 -0.3842339593  0.9968224736 -0.8086459427  0.8868701042
## [231] -0.3780727327  2.5758449791  1.7148315670  2.7324272009  0.8332397531
## [236]  1.0009507824  1.9685409632  2.3697016706  1.3812051877  2.6212638095
## [241]  1.9812571526  0.7688579152  0.2944286504  0.2373890442  0.0905573537
## [246]  0.1444155868  0.2068117180 -0.1686321278  0.5768913360  0.6174192653
## [251]  0.2471049651  2.1248481028 -0.8621236553  1.8551046478 -0.7396138335
## [256]  0.9953012828  1.1706687453 -0.2612307520  1.0922108791 -1.6247741546
## [261] -0.0303707421 -2.2773534114  0.2039318009 -0.9852282256 -0.8710586780
## [266] -0.3454705217 -0.7734511977 -0.8588926361  0.5258935590 -0.6277777871
## [271]  0.1381115635  0.3688323198  0.5049496838  0.1912585536 -0.4319266648
## [276] -1.3755588492 -0.3239822272 -0.4062433845  0.7200298762  0.1349736491
## [281] -0.3088818566 -0.2619393812 -0.9094469352 -0.6455037033  0.4139233572
## [286]  1.2062168717  2.4547921170  1.4016281232  0.0525150278 -0.2901311561
## [291]  0.0027978397  0.5333436989  0.5582367761  0.1770709978 -0.0980639856
## [296]  0.3733346775 -1.7322856400  0.7996808082
cor(yt_ma2,yt_2_ma2)
## [1] 0.3985644

Korelasi antara \(Y_t\) dengan \(Y_{t-2}\) hasil simulasi 0.3985644

plot(y=yt_ma2,x=yt_2_ma2)

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

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

#Yt
yt_ma2 <- ma2[-c(1,2,3)]
yt_ma2
##   [1]  1.2931078276  0.0480891236 -1.3443863362 -0.2071210815  0.6596565425
##   [6]  0.2030366571  1.2024391609  0.7593035708  0.7033449886  1.9403469147
##  [11]  0.3925484551  0.6674976688 -0.3446283632  1.9084081647  0.3019882409
##  [16]  0.0756044605 -1.2845018549 -0.7347703151  1.1684735578 -0.7022092018
##  [21]  0.8164260215 -0.0005709686  1.9069194491  1.2030284748  0.0707856096
##  [26] -1.3810693189 -1.6142778433 -0.6245852823 -0.8725018478  0.2341620404
##  [31] -0.6939341378 -0.4827299922  1.3884701207 -0.9152117468  0.0387632465
##  [36] -1.6400317856  1.0005821561  0.7046606538  0.1053001179 -0.7675444479
##  [41] -0.3746294673  0.0867119079  0.0624423465  1.0284534633  0.5889407161
##  [46]  2.0826487470  0.8222595799  0.9659892717  1.3617771939  0.2808865606
##  [51]  0.2927791590 -1.2425251238 -0.6145897515  0.2305059778 -0.0008796766
##  [56] -0.3538948232 -1.3370825139 -1.0768203043 -0.8889290122  0.7482329302
##  [61] -0.4956215950  0.8665308492  0.6985899983  0.5059316503  3.4378466046
##  [66]  1.1085522764  0.6293708571 -0.3546625549 -0.6117615042  1.0054429401
##  [71]  2.0239920538  0.9722914878  1.7884856065 -0.9500941082 -1.2890124481
##  [76]  0.1920572179 -0.3562315333  1.9317168346  0.0930827747  0.7722635840
##  [81] -1.3645812477  1.1925189739 -0.1266541905  1.9254811223  0.3148387204
##  [86] -0.4656714742 -0.5976814383 -0.1252779443  2.0231193708  2.4625345920
##  [91]  2.1910596217  1.4214113024  0.8766225940  0.9267589084 -0.8232050274
##  [96] -1.6264722750 -2.0437599459  0.0593472813 -0.4766026587 -0.4274172270
## [101]  0.5865156735 -2.5723728557  0.2018284826 -1.3864904483 -0.2671476548
## [106] -0.1622579378 -1.8886213965  0.0963531485 -0.5773190694  1.9487790570
## [111]  1.3912223790  1.6739861739  0.8671740946  0.9379216612 -1.2430639940
## [116] -1.2425258378 -3.7908666936  0.1054106417 -1.0097051137 -0.1444730816
## [121] -1.3360990732 -0.7395354999 -0.5234724890  1.1519528340 -0.7542851340
## [126]  0.5545346831  1.0773612788  2.1864016426  1.3575846676 -0.0603187191
## [131] -1.3182072883 -1.4831605057 -2.2369214890 -1.5564018418 -1.5200332576
## [136]  0.5518822885 -0.5403428041 -1.0113170122 -0.4044165025  0.3765462648
## [141] -0.5139685156  0.2227773739 -0.8298204850  0.1493382246  0.4209347510
## [146]  1.5354375656  1.5069008021  1.4404986178 -1.1516092916 -0.2291156817
## [151] -1.8238967982 -1.2169569496 -0.3471614692  0.8206307081  1.2674616742
## [156]  2.3185736810 -0.6890438106  0.2954115052 -0.0694363757  0.8270306299
## [161]  1.2112715185 -1.3932545390 -0.6249472403 -0.5380299092 -0.0956441836
## [166]  0.0714389431 -1.5618061241  0.0605293549 -0.5223492304  0.2232705480
## [171]  1.1938956098  0.3911999599  1.4792286808  0.5822047003  1.5292924790
## [176]  0.9925623705  2.2805912681  0.6918573713  1.2662349029 -0.6728839038
## [181]  0.5485919729  1.3758753904  1.2765154339  1.6191261090 -0.5721040622
## [186]  0.6914655381 -2.4633202551 -1.7141729685 -4.3145435835 -2.1094561668
## [191] -1.1148026417  0.5188166714  0.4280945822  0.6413359989  1.7023184786
## [196]  1.5466777022  2.4972648386  1.8464181654  0.4783098581  0.2668014391
## [201]  0.6609506233 -2.6271836829 -1.0271632093  0.7188278491 -1.4071705984
## [206]  2.5029596596 -2.1767000016  0.2261918704 -1.3393432359  0.7714065328
## [211]  0.4177407565 -1.8540075065 -1.2359973739 -1.3729928044 -0.6071069445
## [216]  0.2325083951 -0.8897303942  0.7797076467 -0.5835862514  0.3875298318
## [221] -1.5752881050 -1.6394575680 -0.6532492389 -0.3842339593  0.9968224736
## [226] -0.8086459427  0.8868701042 -0.3780727327  2.5758449791  1.7148315670
## [231]  2.7324272009  0.8332397531  1.0009507824  1.9685409632  2.3697016706
## [236]  1.3812051877  2.6212638095  1.9812571526  0.7688579152  0.2944286504
## [241]  0.2373890442  0.0905573537  0.1444155868  0.2068117180 -0.1686321278
## [246]  0.5768913360  0.6174192653  0.2471049651  2.1248481028 -0.8621236553
## [251]  1.8551046478 -0.7396138335  0.9953012828  1.1706687453 -0.2612307520
## [256]  1.0922108791 -1.6247741546 -0.0303707421 -2.2773534114  0.2039318009
## [261] -0.9852282256 -0.8710586780 -0.3454705217 -0.7734511977 -0.8588926361
## [266]  0.5258935590 -0.6277777871  0.1381115635  0.3688323198  0.5049496838
## [271]  0.1912585536 -0.4319266648 -1.3755588492 -0.3239822272 -0.4062433845
## [276]  0.7200298762  0.1349736491 -0.3088818566 -0.2619393812 -0.9094469352
## [281] -0.6455037033  0.4139233572  1.2062168717  2.4547921170  1.4016281232
## [286]  0.0525150278 -0.2901311561  0.0027978397  0.5333436989  0.5582367761
## [291]  0.1770709978 -0.0980639856  0.3733346775 -1.7322856400  0.7996808082
## [296] -1.0146825427  2.1128443720
#Yt-2
yt_3_ma2 <- ma2[-c(298,299,300)]
yt_3_ma2
##   [1] -0.2913725396  1.9471847822  0.2039450696  1.2931078276  0.0480891236
##   [6] -1.3443863362 -0.2071210815  0.6596565425  0.2030366571  1.2024391609
##  [11]  0.7593035708  0.7033449886  1.9403469147  0.3925484551  0.6674976688
##  [16] -0.3446283632  1.9084081647  0.3019882409  0.0756044605 -1.2845018549
##  [21] -0.7347703151  1.1684735578 -0.7022092018  0.8164260215 -0.0005709686
##  [26]  1.9069194491  1.2030284748  0.0707856096 -1.3810693189 -1.6142778433
##  [31] -0.6245852823 -0.8725018478  0.2341620404 -0.6939341378 -0.4827299922
##  [36]  1.3884701207 -0.9152117468  0.0387632465 -1.6400317856  1.0005821561
##  [41]  0.7046606538  0.1053001179 -0.7675444479 -0.3746294673  0.0867119079
##  [46]  0.0624423465  1.0284534633  0.5889407161  2.0826487470  0.8222595799
##  [51]  0.9659892717  1.3617771939  0.2808865606  0.2927791590 -1.2425251238
##  [56] -0.6145897515  0.2305059778 -0.0008796766 -0.3538948232 -1.3370825139
##  [61] -1.0768203043 -0.8889290122  0.7482329302 -0.4956215950  0.8665308492
##  [66]  0.6985899983  0.5059316503  3.4378466046  1.1085522764  0.6293708571
##  [71] -0.3546625549 -0.6117615042  1.0054429401  2.0239920538  0.9722914878
##  [76]  1.7884856065 -0.9500941082 -1.2890124481  0.1920572179 -0.3562315333
##  [81]  1.9317168346  0.0930827747  0.7722635840 -1.3645812477  1.1925189739
##  [86] -0.1266541905  1.9254811223  0.3148387204 -0.4656714742 -0.5976814383
##  [91] -0.1252779443  2.0231193708  2.4625345920  2.1910596217  1.4214113024
##  [96]  0.8766225940  0.9267589084 -0.8232050274 -1.6264722750 -2.0437599459
## [101]  0.0593472813 -0.4766026587 -0.4274172270  0.5865156735 -2.5723728557
## [106]  0.2018284826 -1.3864904483 -0.2671476548 -0.1622579378 -1.8886213965
## [111]  0.0963531485 -0.5773190694  1.9487790570  1.3912223790  1.6739861739
## [116]  0.8671740946  0.9379216612 -1.2430639940 -1.2425258378 -3.7908666936
## [121]  0.1054106417 -1.0097051137 -0.1444730816 -1.3360990732 -0.7395354999
## [126] -0.5234724890  1.1519528340 -0.7542851340  0.5545346831  1.0773612788
## [131]  2.1864016426  1.3575846676 -0.0603187191 -1.3182072883 -1.4831605057
## [136] -2.2369214890 -1.5564018418 -1.5200332576  0.5518822885 -0.5403428041
## [141] -1.0113170122 -0.4044165025  0.3765462648 -0.5139685156  0.2227773739
## [146] -0.8298204850  0.1493382246  0.4209347510  1.5354375656  1.5069008021
## [151]  1.4404986178 -1.1516092916 -0.2291156817 -1.8238967982 -1.2169569496
## [156] -0.3471614692  0.8206307081  1.2674616742  2.3185736810 -0.6890438106
## [161]  0.2954115052 -0.0694363757  0.8270306299  1.2112715185 -1.3932545390
## [166] -0.6249472403 -0.5380299092 -0.0956441836  0.0714389431 -1.5618061241
## [171]  0.0605293549 -0.5223492304  0.2232705480  1.1938956098  0.3911999599
## [176]  1.4792286808  0.5822047003  1.5292924790  0.9925623705  2.2805912681
## [181]  0.6918573713  1.2662349029 -0.6728839038  0.5485919729  1.3758753904
## [186]  1.2765154339  1.6191261090 -0.5721040622  0.6914655381 -2.4633202551
## [191] -1.7141729685 -4.3145435835 -2.1094561668 -1.1148026417  0.5188166714
## [196]  0.4280945822  0.6413359989  1.7023184786  1.5466777022  2.4972648386
## [201]  1.8464181654  0.4783098581  0.2668014391  0.6609506233 -2.6271836829
## [206] -1.0271632093  0.7188278491 -1.4071705984  2.5029596596 -2.1767000016
## [211]  0.2261918704 -1.3393432359  0.7714065328  0.4177407565 -1.8540075065
## [216] -1.2359973739 -1.3729928044 -0.6071069445  0.2325083951 -0.8897303942
## [221]  0.7797076467 -0.5835862514  0.3875298318 -1.5752881050 -1.6394575680
## [226] -0.6532492389 -0.3842339593  0.9968224736 -0.8086459427  0.8868701042
## [231] -0.3780727327  2.5758449791  1.7148315670  2.7324272009  0.8332397531
## [236]  1.0009507824  1.9685409632  2.3697016706  1.3812051877  2.6212638095
## [241]  1.9812571526  0.7688579152  0.2944286504  0.2373890442  0.0905573537
## [246]  0.1444155868  0.2068117180 -0.1686321278  0.5768913360  0.6174192653
## [251]  0.2471049651  2.1248481028 -0.8621236553  1.8551046478 -0.7396138335
## [256]  0.9953012828  1.1706687453 -0.2612307520  1.0922108791 -1.6247741546
## [261] -0.0303707421 -2.2773534114  0.2039318009 -0.9852282256 -0.8710586780
## [266] -0.3454705217 -0.7734511977 -0.8588926361  0.5258935590 -0.6277777871
## [271]  0.1381115635  0.3688323198  0.5049496838  0.1912585536 -0.4319266648
## [276] -1.3755588492 -0.3239822272 -0.4062433845  0.7200298762  0.1349736491
## [281] -0.3088818566 -0.2619393812 -0.9094469352 -0.6455037033  0.4139233572
## [286]  1.2062168717  2.4547921170  1.4016281232  0.0525150278 -0.2901311561
## [291]  0.0027978397  0.5333436989  0.5582367761  0.1770709978 -0.0980639856
## [296]  0.3733346775 -1.7322856400
cor(yt_ma2,yt_3_ma2)
## [1] -0.01106738

Korelasi antara \(Y_t\) dengan \(Y_{t-3}\) hasil simulasi mendekati teori yang ada yaitu -0.01106738

plot(y=yt_ma2,x=yt_3_ma2)

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

Proses AR

Proses AR dapat dituliskan sebagai berikut:

\[ y_{t} = c + e_t + \phi_{1}Y_{t-1} + \phi_{2}Y_{t-2} + \dots + \phi_{q}Y_{t-q} = c+{e_t+\sum_{i=1}^p \phi_iY_{t-i}} \] Terlihat bahwa \(Y_t\) berperan penting dalam pembangkitan proses AR.

Pembangkitan Proses AR

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

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

set.seed(1002)
n<-length(wn)
n
## [1] 300
ar <- c(2:n) 
for (i in 3:n) {ar[i]<-wn[i]+0.5*ar[i-1]+0.2*ar[i-2]}
ar
##   [1]  2.0000000000  3.0000000000  1.5777489568  3.2941825568  1.5978135339
##   [6]  1.7535972732  1.3450053906 -0.5581342021  0.3261690081  1.5254340049
##  [11]  0.2396559060  0.9782860694  1.4280061994  0.9246097195  2.1477140618
##  [16]  1.0824346015  0.8689107540  0.4528603017  2.4489628800  0.9163907073
##  [21] -0.0461928397 -0.4874501497 -0.1321727478  1.3451599187 -0.7320328580
##  [26]  0.3654710899  0.6776827513  1.7848402105  1.2970110168  0.1448946455
##  [31] -0.8664208476 -1.0228538455 -0.3428852101 -1.0140721643 -0.2913230970
##  [36] -0.7732908559 -0.9282881060  1.2179080447 -0.9365726180 -0.7440200072
##  [41] -1.1757087785  0.8220666502  0.6268927577 -0.5324756731 -0.7748702931
##  [46] -0.0087541161  0.1136969301 -0.2827849295  0.8811245850  0.7757645000
##  [51]  1.8901856384  1.1570183945  1.1041794437  2.0521537420  0.9317553126
##  [56]  0.5339543378 -0.4631607973 -0.1673712310  0.6211143001 -0.0172205828
##  [61] -0.5990201049 -1.1776015215 -1.0067865409 -0.9837814718  0.3318411004
##  [66] -0.7895722587  0.2265540591  0.8872056975  0.2891248820  3.2806598247
##  [71]  1.7431179347  0.3638828245  0.6144478598  0.4329707110  1.2733000647
##  [76]  2.3418840437  1.1900824926  1.9749275569  0.0520940933 -0.9455311177
##  [81]  0.9803676582  0.1876985183  1.4013626213  0.4547553092  0.7264361466
##  [86] -0.8278470766  1.3054175689  0.5000733545  1.4869953924  0.7602406157
##  [91] -0.3403685081 -0.1586993606  0.3942567023  2.0561737540  2.4881506489
##  [96]  2.1594135594  1.9683793594  1.8338159151  1.8356198584  0.0007075591
## [101] -1.0604699200 -1.2323549937  0.3687490214 -0.5961504203 -1.1563333613
## [106]  0.5823544504 -2.4651580155 -0.6721029368 -0.8781344511 -1.0874180244
## [111] -0.6465909279 -2.1501403282 -0.5079376822 -0.5742794875  1.0982944086
## [116]  1.1648745588  1.2916360209  1.1118011217  1.3652222306 -0.6982953603
## [121] -1.0079190711 -3.0997989464 -0.1045110079 -0.8670011155 -1.5091448797
## [126] -1.7253033946 -0.9522386083 -0.9511508590  0.4105727942 -1.0918847612
## [131] -0.1124743113  1.3263703587  1.9758860667  1.1161327929  0.1466411658
## [136] -0.6167685819 -0.9129288077 -2.0152010753 -1.7921113090 -1.7171293502
## [141] -0.1367362503 -1.1334169855 -1.9648739708 -0.6322357996  0.2591906744
## [146] -1.2442644354 -0.4295216849 -0.6012956061 -0.2666046035  0.2020034393
## [151]  1.3289238978  1.4259272819  1.3620753210 -0.7713557220  0.1226569167
## [156] -0.9686600663 -1.4680204754 -0.3461845617  0.7262443519  0.7352360331
## [161]  1.9391358235 -0.4077467286  0.2333486824  0.8605477752  0.9441682128
## [166]  1.1733216766 -1.1097460174 -0.5085365235  0.1922280646 -0.2556189579
## [171] -0.3189819666 -1.5305582475 -0.1027979128 -0.3784047944 -0.4139003189
## [176]  1.0054563402  0.4183960863  1.1172863248  0.9426594865  1.6797464363
## [181]  1.4467814506  2.5816050898  1.4120843743  1.6424688459  0.3635698141
## [186]  1.1028398582  2.2070336998  1.6119036231  1.8016172551  0.2566905276
## [191]  1.2341785606 -1.5131975128 -1.7985919608 -3.6919725607 -2.5458486583
## [196] -1.4960416420 -0.7403983695 -0.7571961238 -0.1603016025  1.3768511657
## [201]  1.3398408079  2.2041005425  2.3028273087  0.9421341274  0.8987884932
## [206]  1.7019690895 -2.0023942272 -1.1132007272  1.7625894950 -1.5649450191
## [211]  1.3306436751 -1.1944467094 -0.5425499034 -0.8368576901  0.5020182359
## [216]  0.2858115497 -2.3089419094 -1.4337098680 -0.8857248322 -1.2520379937
## [221] -0.5374332169 -1.2016867375  0.1849641988 -0.6792216656 -0.2385181208
## [226] -1.5372115969 -1.9813836327 -0.7160887685 -0.6723286910  0.1354161862
## [231] -1.1705183538  0.4013194768 -0.1330584065  2.0537282110  1.9588552681
## [236]  2.5151632283  1.4574347337  1.6344739973  3.0313260751  3.2015842648
## [241]  1.8910906862  3.5180968134  3.5352098463  1.5215641097  1.3033507636
## [246]  1.8289626578  1.0152030100  0.5580043396  0.9109794516  0.4161176122
## [251]  0.7701732172  1.0243457770  0.4629471262  2.3088735960 -0.2421535396
## [256]  1.6679559758  0.4085380936  0.8876103835  1.7824870110  0.0948950650
## [261]  1.1315195004 -0.7467429074 -0.0813903669 -1.6947790487 -0.0972479954
## [266] -0.7765347037 -1.5830454318 -0.5887958482 -0.8224746430 -1.5181223592
## [271]  0.1248683775 -0.6948623436 -0.6319318000  0.3098869089  0.4132612494
## [276] -0.1529102684 -0.4879447321 -1.1995455649 -0.3548623894 -0.4055887408
## [281]  0.2360627975 -0.0390954987 -0.5567111742 -0.2687581847 -0.8115092727
## [286] -0.8891446997  0.3183772907  1.0752590349  2.0633864637  1.4072009691
## [291]  0.2273615401  0.3642827445  0.7760965501  0.7933583066  0.6480641244
## [296]  0.4218363672  0.2091145687  0.6513462250 -1.4709084168  0.6524046217

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

set.seed(1002)
ar2 <- arima.sim(list(order=c(2,0,0), ar=c(0.5,0.2)), n=300)
ar2
## Time Series:
## Start = 1 
## End = 300 
## Frequency = 1 
##   [1]  0.3617754456  0.6748653860  1.7826923989  1.2953736379  0.1436463938
##   [6] -0.8673724492 -1.0235792966 -0.3434382560 -1.0144937775 -0.2916445128
##  [11] -0.7735358864 -0.9284749044  1.2177656394 -0.9366811803 -0.7441027694
##  [16] -1.1757718721  0.8220185510  0.6268560893 -0.5325036271 -0.7748916038
##  [21] -0.0087703622  0.1136845449 -0.2827943713  0.8811173871  0.7757590126
##  [26]  1.8901814551  1.1570152054  1.1041770125  2.0521518885  0.9317538996
##  [31]  0.5339532607 -0.4631616185 -0.1673718570  0.6211138228 -0.0172209466
##  [36] -0.5990203823 -1.1776017330 -1.0067867021 -0.9837815947  0.3318410068
##  [41] -0.7895723302  0.2265540046  0.8872056560  0.2891248503  3.2806598006
##  [46]  1.7431179163  0.3638828105  0.6144478491  0.4329707028  1.2733000585
##  [51]  2.3418840390  1.1900824890  1.9749275542  0.0520940912 -0.9455311193
##  [56]  0.9803676570  0.1876985174  1.4013626206  0.4547553087  0.7264361462
##  [61] -0.8278470769  1.3054175687  0.5000733543  1.4869953923  0.7602406156
##  [66] -0.3403685082 -0.1586993606  0.3942567023  2.0561737539  2.4881506489
##  [71]  2.1594135594  1.9683793593  1.8338159151  1.8356198584  0.0007075591
##  [76] -1.0604699200 -1.2323549937  0.3687490214 -0.5961504203 -1.1563333613
##  [81]  0.5823544503 -2.4651580155 -0.6721029368 -0.8781344511 -1.0874180244
##  [86] -0.6465909279 -2.1501403282 -0.5079376822 -0.5742794875  1.0982944086
##  [91]  1.1648745588  1.2916360209  1.1118011217  1.3652222306 -0.6982953603
##  [96] -1.0079190711 -3.0997989464 -0.1045110079 -0.8670011155 -1.5091448797
## [101] -1.7253033946 -0.9522386083 -0.9511508590  0.4105727942 -1.0918847612
## [106] -0.1124743113  1.3263703587  1.9758860667  1.1161327929  0.1466411658
## [111] -0.6167685819 -0.9129288077 -2.0152010753 -1.7921113090 -1.7171293502
## [116] -0.1367362503 -1.1334169855 -1.9648739708 -0.6322357996  0.2591906744
## [121] -1.2442644354 -0.4295216849 -0.6012956061 -0.2666046035  0.2020034393
## [126]  1.3289238978  1.4259272819  1.3620753210 -0.7713557220  0.1226569167
## [131] -0.9686600663 -1.4680204754 -0.3461845617  0.7262443519  0.7352360331
## [136]  1.9391358235 -0.4077467286  0.2333486824  0.8605477752  0.9441682128
## [141]  1.1733216766 -1.1097460174 -0.5085365235  0.1922280646 -0.2556189579
## [146] -0.3189819666 -1.5305582475 -0.1027979128 -0.3784047944 -0.4139003189
## [151]  1.0054563402  0.4183960863  1.1172863248  0.9426594865  1.6797464363
## [156]  1.4467814506  2.5816050898  1.4120843743  1.6424688459  0.3635698141
## [161]  1.1028398582  2.2070336998  1.6119036231  1.8016172551  0.2566905276
## [166]  1.2341785606 -1.5131975128 -1.7985919608 -3.6919725607 -2.5458486583
## [171] -1.4960416420 -0.7403983695 -0.7571961238 -0.1603016025  1.3768511657
## [176]  1.3398408079  2.2041005425  2.3028273087  0.9421341274  0.8987884932
## [181]  1.7019690895 -2.0023942272 -1.1132007272  1.7625894950 -1.5649450191
## [186]  1.3306436751 -1.1944467094 -0.5425499034 -0.8368576901  0.5020182359
## [191]  0.2858115497 -2.3089419094 -1.4337098680 -0.8857248322 -1.2520379937
## [196] -0.5374332169 -1.2016867375  0.1849641988 -0.6792216656 -0.2385181208
## [201] -1.5372115969 -1.9813836327 -0.7160887685 -0.6723286910  0.1354161862
## [206] -1.1705183538  0.4013194768 -0.1330584065  2.0537282110  1.9588552681
## [211]  2.5151632283  1.4574347337  1.6344739973  3.0313260751  3.2015842648
## [216]  1.8910906862  3.5180968134  3.5352098463  1.5215641097  1.3033507636
## [221]  1.8289626578  1.0152030100  0.5580043396  0.9109794516  0.4161176122
## [226]  0.7701732172  1.0243457770  0.4629471262  2.3088735960 -0.2421535396
## [231]  1.6679559758  0.4085380936  0.8876103835  1.7824870110  0.0948950650
## [236]  1.1315195004 -0.7467429074 -0.0813903669 -1.6947790487 -0.0972479954
## [241] -0.7765347037 -1.5830454318 -0.5887958482 -0.8224746430 -1.5181223592
## [246]  0.1248683775 -0.6948623436 -0.6319318000  0.3098869089  0.4132612494
## [251] -0.1529102684 -0.4879447321 -1.1995455649 -0.3548623894 -0.4055887408
## [256]  0.2360627975 -0.0390954987 -0.5567111742 -0.2687581847 -0.8115092727
## [261] -0.8891446997  0.3183772907  1.0752590349  2.0633864637  1.4072009691
## [266]  0.2273615401  0.3642827445  0.7760965501  0.7933583066  0.6480641244
## [271]  0.4218363672  0.2091145687  0.6513462250 -1.4709084168  0.6524046217
## [276] -0.3826550834  1.4633142879  0.7169196898 -0.3157065182 -0.8610409829
## [281]  0.2494666233 -1.2014939550 -0.1312093416 -0.0839659963  1.4356598933
## [286]  0.5068877271  0.7486908492  1.0053755569  1.6392870638  2.3148615884
## [291]  2.5494925896  1.5025221432 -0.0820571327  0.8241497586 -0.6585846350
## [296]  1.2699916168  0.2566299169  0.5587826461 -0.3150394184  1.7862124219

Karakteristik AR(2)

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 o o o o o o  o  o  o 
## 1 x x o 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 o 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 x x 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 x x o o o o o o  o  o  o

Berdasarkan pola segitiga nol pada plot EACF, tidak terlihat bahwa segitiga nol berada pada ordo AR(2) dan ordo MA(0)

Scatterplot Antar Lag

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

#Yt
yt_ar <- ar[-1]
yt_ar
##   [1]  3.0000000000  1.5777489568  3.2941825568  1.5978135339  1.7535972732
##   [6]  1.3450053906 -0.5581342021  0.3261690081  1.5254340049  0.2396559060
##  [11]  0.9782860694  1.4280061994  0.9246097195  2.1477140618  1.0824346015
##  [16]  0.8689107540  0.4528603017  2.4489628800  0.9163907073 -0.0461928397
##  [21] -0.4874501497 -0.1321727478  1.3451599187 -0.7320328580  0.3654710899
##  [26]  0.6776827513  1.7848402105  1.2970110168  0.1448946455 -0.8664208476
##  [31] -1.0228538455 -0.3428852101 -1.0140721643 -0.2913230970 -0.7732908559
##  [36] -0.9282881060  1.2179080447 -0.9365726180 -0.7440200072 -1.1757087785
##  [41]  0.8220666502  0.6268927577 -0.5324756731 -0.7748702931 -0.0087541161
##  [46]  0.1136969301 -0.2827849295  0.8811245850  0.7757645000  1.8901856384
##  [51]  1.1570183945  1.1041794437  2.0521537420  0.9317553126  0.5339543378
##  [56] -0.4631607973 -0.1673712310  0.6211143001 -0.0172205828 -0.5990201049
##  [61] -1.1776015215 -1.0067865409 -0.9837814718  0.3318411004 -0.7895722587
##  [66]  0.2265540591  0.8872056975  0.2891248820  3.2806598247  1.7431179347
##  [71]  0.3638828245  0.6144478598  0.4329707110  1.2733000647  2.3418840437
##  [76]  1.1900824926  1.9749275569  0.0520940933 -0.9455311177  0.9803676582
##  [81]  0.1876985183  1.4013626213  0.4547553092  0.7264361466 -0.8278470766
##  [86]  1.3054175689  0.5000733545  1.4869953924  0.7602406157 -0.3403685081
##  [91] -0.1586993606  0.3942567023  2.0561737540  2.4881506489  2.1594135594
##  [96]  1.9683793594  1.8338159151  1.8356198584  0.0007075591 -1.0604699200
## [101] -1.2323549937  0.3687490214 -0.5961504203 -1.1563333613  0.5823544504
## [106] -2.4651580155 -0.6721029368 -0.8781344511 -1.0874180244 -0.6465909279
## [111] -2.1501403282 -0.5079376822 -0.5742794875  1.0982944086  1.1648745588
## [116]  1.2916360209  1.1118011217  1.3652222306 -0.6982953603 -1.0079190711
## [121] -3.0997989464 -0.1045110079 -0.8670011155 -1.5091448797 -1.7253033946
## [126] -0.9522386083 -0.9511508590  0.4105727942 -1.0918847612 -0.1124743113
## [131]  1.3263703587  1.9758860667  1.1161327929  0.1466411658 -0.6167685819
## [136] -0.9129288077 -2.0152010753 -1.7921113090 -1.7171293502 -0.1367362503
## [141] -1.1334169855 -1.9648739708 -0.6322357996  0.2591906744 -1.2442644354
## [146] -0.4295216849 -0.6012956061 -0.2666046035  0.2020034393  1.3289238978
## [151]  1.4259272819  1.3620753210 -0.7713557220  0.1226569167 -0.9686600663
## [156] -1.4680204754 -0.3461845617  0.7262443519  0.7352360331  1.9391358235
## [161] -0.4077467286  0.2333486824  0.8605477752  0.9441682128  1.1733216766
## [166] -1.1097460174 -0.5085365235  0.1922280646 -0.2556189579 -0.3189819666
## [171] -1.5305582475 -0.1027979128 -0.3784047944 -0.4139003189  1.0054563402
## [176]  0.4183960863  1.1172863248  0.9426594865  1.6797464363  1.4467814506
## [181]  2.5816050898  1.4120843743  1.6424688459  0.3635698141  1.1028398582
## [186]  2.2070336998  1.6119036231  1.8016172551  0.2566905276  1.2341785606
## [191] -1.5131975128 -1.7985919608 -3.6919725607 -2.5458486583 -1.4960416420
## [196] -0.7403983695 -0.7571961238 -0.1603016025  1.3768511657  1.3398408079
## [201]  2.2041005425  2.3028273087  0.9421341274  0.8987884932  1.7019690895
## [206] -2.0023942272 -1.1132007272  1.7625894950 -1.5649450191  1.3306436751
## [211] -1.1944467094 -0.5425499034 -0.8368576901  0.5020182359  0.2858115497
## [216] -2.3089419094 -1.4337098680 -0.8857248322 -1.2520379937 -0.5374332169
## [221] -1.2016867375  0.1849641988 -0.6792216656 -0.2385181208 -1.5372115969
## [226] -1.9813836327 -0.7160887685 -0.6723286910  0.1354161862 -1.1705183538
## [231]  0.4013194768 -0.1330584065  2.0537282110  1.9588552681  2.5151632283
## [236]  1.4574347337  1.6344739973  3.0313260751  3.2015842648  1.8910906862
## [241]  3.5180968134  3.5352098463  1.5215641097  1.3033507636  1.8289626578
## [246]  1.0152030100  0.5580043396  0.9109794516  0.4161176122  0.7701732172
## [251]  1.0243457770  0.4629471262  2.3088735960 -0.2421535396  1.6679559758
## [256]  0.4085380936  0.8876103835  1.7824870110  0.0948950650  1.1315195004
## [261] -0.7467429074 -0.0813903669 -1.6947790487 -0.0972479954 -0.7765347037
## [266] -1.5830454318 -0.5887958482 -0.8224746430 -1.5181223592  0.1248683775
## [271] -0.6948623436 -0.6319318000  0.3098869089  0.4132612494 -0.1529102684
## [276] -0.4879447321 -1.1995455649 -0.3548623894 -0.4055887408  0.2360627975
## [281] -0.0390954987 -0.5567111742 -0.2687581847 -0.8115092727 -0.8891446997
## [286]  0.3183772907  1.0752590349  2.0633864637  1.4072009691  0.2273615401
## [291]  0.3642827445  0.7760965501  0.7933583066  0.6480641244  0.4218363672
## [296]  0.2091145687  0.6513462250 -1.4709084168  0.6524046217
#Yt-1
yt_1_ar <- ar[-300]
yt_1_ar
##   [1]  2.0000000000  3.0000000000  1.5777489568  3.2941825568  1.5978135339
##   [6]  1.7535972732  1.3450053906 -0.5581342021  0.3261690081  1.5254340049
##  [11]  0.2396559060  0.9782860694  1.4280061994  0.9246097195  2.1477140618
##  [16]  1.0824346015  0.8689107540  0.4528603017  2.4489628800  0.9163907073
##  [21] -0.0461928397 -0.4874501497 -0.1321727478  1.3451599187 -0.7320328580
##  [26]  0.3654710899  0.6776827513  1.7848402105  1.2970110168  0.1448946455
##  [31] -0.8664208476 -1.0228538455 -0.3428852101 -1.0140721643 -0.2913230970
##  [36] -0.7732908559 -0.9282881060  1.2179080447 -0.9365726180 -0.7440200072
##  [41] -1.1757087785  0.8220666502  0.6268927577 -0.5324756731 -0.7748702931
##  [46] -0.0087541161  0.1136969301 -0.2827849295  0.8811245850  0.7757645000
##  [51]  1.8901856384  1.1570183945  1.1041794437  2.0521537420  0.9317553126
##  [56]  0.5339543378 -0.4631607973 -0.1673712310  0.6211143001 -0.0172205828
##  [61] -0.5990201049 -1.1776015215 -1.0067865409 -0.9837814718  0.3318411004
##  [66] -0.7895722587  0.2265540591  0.8872056975  0.2891248820  3.2806598247
##  [71]  1.7431179347  0.3638828245  0.6144478598  0.4329707110  1.2733000647
##  [76]  2.3418840437  1.1900824926  1.9749275569  0.0520940933 -0.9455311177
##  [81]  0.9803676582  0.1876985183  1.4013626213  0.4547553092  0.7264361466
##  [86] -0.8278470766  1.3054175689  0.5000733545  1.4869953924  0.7602406157
##  [91] -0.3403685081 -0.1586993606  0.3942567023  2.0561737540  2.4881506489
##  [96]  2.1594135594  1.9683793594  1.8338159151  1.8356198584  0.0007075591
## [101] -1.0604699200 -1.2323549937  0.3687490214 -0.5961504203 -1.1563333613
## [106]  0.5823544504 -2.4651580155 -0.6721029368 -0.8781344511 -1.0874180244
## [111] -0.6465909279 -2.1501403282 -0.5079376822 -0.5742794875  1.0982944086
## [116]  1.1648745588  1.2916360209  1.1118011217  1.3652222306 -0.6982953603
## [121] -1.0079190711 -3.0997989464 -0.1045110079 -0.8670011155 -1.5091448797
## [126] -1.7253033946 -0.9522386083 -0.9511508590  0.4105727942 -1.0918847612
## [131] -0.1124743113  1.3263703587  1.9758860667  1.1161327929  0.1466411658
## [136] -0.6167685819 -0.9129288077 -2.0152010753 -1.7921113090 -1.7171293502
## [141] -0.1367362503 -1.1334169855 -1.9648739708 -0.6322357996  0.2591906744
## [146] -1.2442644354 -0.4295216849 -0.6012956061 -0.2666046035  0.2020034393
## [151]  1.3289238978  1.4259272819  1.3620753210 -0.7713557220  0.1226569167
## [156] -0.9686600663 -1.4680204754 -0.3461845617  0.7262443519  0.7352360331
## [161]  1.9391358235 -0.4077467286  0.2333486824  0.8605477752  0.9441682128
## [166]  1.1733216766 -1.1097460174 -0.5085365235  0.1922280646 -0.2556189579
## [171] -0.3189819666 -1.5305582475 -0.1027979128 -0.3784047944 -0.4139003189
## [176]  1.0054563402  0.4183960863  1.1172863248  0.9426594865  1.6797464363
## [181]  1.4467814506  2.5816050898  1.4120843743  1.6424688459  0.3635698141
## [186]  1.1028398582  2.2070336998  1.6119036231  1.8016172551  0.2566905276
## [191]  1.2341785606 -1.5131975128 -1.7985919608 -3.6919725607 -2.5458486583
## [196] -1.4960416420 -0.7403983695 -0.7571961238 -0.1603016025  1.3768511657
## [201]  1.3398408079  2.2041005425  2.3028273087  0.9421341274  0.8987884932
## [206]  1.7019690895 -2.0023942272 -1.1132007272  1.7625894950 -1.5649450191
## [211]  1.3306436751 -1.1944467094 -0.5425499034 -0.8368576901  0.5020182359
## [216]  0.2858115497 -2.3089419094 -1.4337098680 -0.8857248322 -1.2520379937
## [221] -0.5374332169 -1.2016867375  0.1849641988 -0.6792216656 -0.2385181208
## [226] -1.5372115969 -1.9813836327 -0.7160887685 -0.6723286910  0.1354161862
## [231] -1.1705183538  0.4013194768 -0.1330584065  2.0537282110  1.9588552681
## [236]  2.5151632283  1.4574347337  1.6344739973  3.0313260751  3.2015842648
## [241]  1.8910906862  3.5180968134  3.5352098463  1.5215641097  1.3033507636
## [246]  1.8289626578  1.0152030100  0.5580043396  0.9109794516  0.4161176122
## [251]  0.7701732172  1.0243457770  0.4629471262  2.3088735960 -0.2421535396
## [256]  1.6679559758  0.4085380936  0.8876103835  1.7824870110  0.0948950650
## [261]  1.1315195004 -0.7467429074 -0.0813903669 -1.6947790487 -0.0972479954
## [266] -0.7765347037 -1.5830454318 -0.5887958482 -0.8224746430 -1.5181223592
## [271]  0.1248683775 -0.6948623436 -0.6319318000  0.3098869089  0.4132612494
## [276] -0.1529102684 -0.4879447321 -1.1995455649 -0.3548623894 -0.4055887408
## [281]  0.2360627975 -0.0390954987 -0.5567111742 -0.2687581847 -0.8115092727
## [286] -0.8891446997  0.3183772907  1.0752590349  2.0633864637  1.4072009691
## [291]  0.2273615401  0.3642827445  0.7760965501  0.7933583066  0.6480641244
## [296]  0.4218363672  0.2091145687  0.6513462250 -1.4709084168
cor(yt_ar,yt_1_ar)
## [1] 0.5799812

Korelasi antara \(Y_t\) dengan \(Y_{t-1}\) dari hasil simulasi sebesar 0.5799812

plot(y=yt_ar,x=yt_1_ar)

Berdasarkan scatterplot tersebut, terlihat bahwa cenderung terdapat hubungan positif antara \(Y_t\) dengan \(Y_{t-1}\).

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

#Yt
yt2_ar <- ar[-c(1,2)]
yt2_ar
##   [1]  1.5777489568  3.2941825568  1.5978135339  1.7535972732  1.3450053906
##   [6] -0.5581342021  0.3261690081  1.5254340049  0.2396559060  0.9782860694
##  [11]  1.4280061994  0.9246097195  2.1477140618  1.0824346015  0.8689107540
##  [16]  0.4528603017  2.4489628800  0.9163907073 -0.0461928397 -0.4874501497
##  [21] -0.1321727478  1.3451599187 -0.7320328580  0.3654710899  0.6776827513
##  [26]  1.7848402105  1.2970110168  0.1448946455 -0.8664208476 -1.0228538455
##  [31] -0.3428852101 -1.0140721643 -0.2913230970 -0.7732908559 -0.9282881060
##  [36]  1.2179080447 -0.9365726180 -0.7440200072 -1.1757087785  0.8220666502
##  [41]  0.6268927577 -0.5324756731 -0.7748702931 -0.0087541161  0.1136969301
##  [46] -0.2827849295  0.8811245850  0.7757645000  1.8901856384  1.1570183945
##  [51]  1.1041794437  2.0521537420  0.9317553126  0.5339543378 -0.4631607973
##  [56] -0.1673712310  0.6211143001 -0.0172205828 -0.5990201049 -1.1776015215
##  [61] -1.0067865409 -0.9837814718  0.3318411004 -0.7895722587  0.2265540591
##  [66]  0.8872056975  0.2891248820  3.2806598247  1.7431179347  0.3638828245
##  [71]  0.6144478598  0.4329707110  1.2733000647  2.3418840437  1.1900824926
##  [76]  1.9749275569  0.0520940933 -0.9455311177  0.9803676582  0.1876985183
##  [81]  1.4013626213  0.4547553092  0.7264361466 -0.8278470766  1.3054175689
##  [86]  0.5000733545  1.4869953924  0.7602406157 -0.3403685081 -0.1586993606
##  [91]  0.3942567023  2.0561737540  2.4881506489  2.1594135594  1.9683793594
##  [96]  1.8338159151  1.8356198584  0.0007075591 -1.0604699200 -1.2323549937
## [101]  0.3687490214 -0.5961504203 -1.1563333613  0.5823544504 -2.4651580155
## [106] -0.6721029368 -0.8781344511 -1.0874180244 -0.6465909279 -2.1501403282
## [111] -0.5079376822 -0.5742794875  1.0982944086  1.1648745588  1.2916360209
## [116]  1.1118011217  1.3652222306 -0.6982953603 -1.0079190711 -3.0997989464
## [121] -0.1045110079 -0.8670011155 -1.5091448797 -1.7253033946 -0.9522386083
## [126] -0.9511508590  0.4105727942 -1.0918847612 -0.1124743113  1.3263703587
## [131]  1.9758860667  1.1161327929  0.1466411658 -0.6167685819 -0.9129288077
## [136] -2.0152010753 -1.7921113090 -1.7171293502 -0.1367362503 -1.1334169855
## [141] -1.9648739708 -0.6322357996  0.2591906744 -1.2442644354 -0.4295216849
## [146] -0.6012956061 -0.2666046035  0.2020034393  1.3289238978  1.4259272819
## [151]  1.3620753210 -0.7713557220  0.1226569167 -0.9686600663 -1.4680204754
## [156] -0.3461845617  0.7262443519  0.7352360331  1.9391358235 -0.4077467286
## [161]  0.2333486824  0.8605477752  0.9441682128  1.1733216766 -1.1097460174
## [166] -0.5085365235  0.1922280646 -0.2556189579 -0.3189819666 -1.5305582475
## [171] -0.1027979128 -0.3784047944 -0.4139003189  1.0054563402  0.4183960863
## [176]  1.1172863248  0.9426594865  1.6797464363  1.4467814506  2.5816050898
## [181]  1.4120843743  1.6424688459  0.3635698141  1.1028398582  2.2070336998
## [186]  1.6119036231  1.8016172551  0.2566905276  1.2341785606 -1.5131975128
## [191] -1.7985919608 -3.6919725607 -2.5458486583 -1.4960416420 -0.7403983695
## [196] -0.7571961238 -0.1603016025  1.3768511657  1.3398408079  2.2041005425
## [201]  2.3028273087  0.9421341274  0.8987884932  1.7019690895 -2.0023942272
## [206] -1.1132007272  1.7625894950 -1.5649450191  1.3306436751 -1.1944467094
## [211] -0.5425499034 -0.8368576901  0.5020182359  0.2858115497 -2.3089419094
## [216] -1.4337098680 -0.8857248322 -1.2520379937 -0.5374332169 -1.2016867375
## [221]  0.1849641988 -0.6792216656 -0.2385181208 -1.5372115969 -1.9813836327
## [226] -0.7160887685 -0.6723286910  0.1354161862 -1.1705183538  0.4013194768
## [231] -0.1330584065  2.0537282110  1.9588552681  2.5151632283  1.4574347337
## [236]  1.6344739973  3.0313260751  3.2015842648  1.8910906862  3.5180968134
## [241]  3.5352098463  1.5215641097  1.3033507636  1.8289626578  1.0152030100
## [246]  0.5580043396  0.9109794516  0.4161176122  0.7701732172  1.0243457770
## [251]  0.4629471262  2.3088735960 -0.2421535396  1.6679559758  0.4085380936
## [256]  0.8876103835  1.7824870110  0.0948950650  1.1315195004 -0.7467429074
## [261] -0.0813903669 -1.6947790487 -0.0972479954 -0.7765347037 -1.5830454318
## [266] -0.5887958482 -0.8224746430 -1.5181223592  0.1248683775 -0.6948623436
## [271] -0.6319318000  0.3098869089  0.4132612494 -0.1529102684 -0.4879447321
## [276] -1.1995455649 -0.3548623894 -0.4055887408  0.2360627975 -0.0390954987
## [281] -0.5567111742 -0.2687581847 -0.8115092727 -0.8891446997  0.3183772907
## [286]  1.0752590349  2.0633864637  1.4072009691  0.2273615401  0.3642827445
## [291]  0.7760965501  0.7933583066  0.6480641244  0.4218363672  0.2091145687
## [296]  0.6513462250 -1.4709084168  0.6524046217
#Yt-2
yt_2_ar <- ar[-c(299,300)]
yt_2_ar
##   [1]  2.0000000000  3.0000000000  1.5777489568  3.2941825568  1.5978135339
##   [6]  1.7535972732  1.3450053906 -0.5581342021  0.3261690081  1.5254340049
##  [11]  0.2396559060  0.9782860694  1.4280061994  0.9246097195  2.1477140618
##  [16]  1.0824346015  0.8689107540  0.4528603017  2.4489628800  0.9163907073
##  [21] -0.0461928397 -0.4874501497 -0.1321727478  1.3451599187 -0.7320328580
##  [26]  0.3654710899  0.6776827513  1.7848402105  1.2970110168  0.1448946455
##  [31] -0.8664208476 -1.0228538455 -0.3428852101 -1.0140721643 -0.2913230970
##  [36] -0.7732908559 -0.9282881060  1.2179080447 -0.9365726180 -0.7440200072
##  [41] -1.1757087785  0.8220666502  0.6268927577 -0.5324756731 -0.7748702931
##  [46] -0.0087541161  0.1136969301 -0.2827849295  0.8811245850  0.7757645000
##  [51]  1.8901856384  1.1570183945  1.1041794437  2.0521537420  0.9317553126
##  [56]  0.5339543378 -0.4631607973 -0.1673712310  0.6211143001 -0.0172205828
##  [61] -0.5990201049 -1.1776015215 -1.0067865409 -0.9837814718  0.3318411004
##  [66] -0.7895722587  0.2265540591  0.8872056975  0.2891248820  3.2806598247
##  [71]  1.7431179347  0.3638828245  0.6144478598  0.4329707110  1.2733000647
##  [76]  2.3418840437  1.1900824926  1.9749275569  0.0520940933 -0.9455311177
##  [81]  0.9803676582  0.1876985183  1.4013626213  0.4547553092  0.7264361466
##  [86] -0.8278470766  1.3054175689  0.5000733545  1.4869953924  0.7602406157
##  [91] -0.3403685081 -0.1586993606  0.3942567023  2.0561737540  2.4881506489
##  [96]  2.1594135594  1.9683793594  1.8338159151  1.8356198584  0.0007075591
## [101] -1.0604699200 -1.2323549937  0.3687490214 -0.5961504203 -1.1563333613
## [106]  0.5823544504 -2.4651580155 -0.6721029368 -0.8781344511 -1.0874180244
## [111] -0.6465909279 -2.1501403282 -0.5079376822 -0.5742794875  1.0982944086
## [116]  1.1648745588  1.2916360209  1.1118011217  1.3652222306 -0.6982953603
## [121] -1.0079190711 -3.0997989464 -0.1045110079 -0.8670011155 -1.5091448797
## [126] -1.7253033946 -0.9522386083 -0.9511508590  0.4105727942 -1.0918847612
## [131] -0.1124743113  1.3263703587  1.9758860667  1.1161327929  0.1466411658
## [136] -0.6167685819 -0.9129288077 -2.0152010753 -1.7921113090 -1.7171293502
## [141] -0.1367362503 -1.1334169855 -1.9648739708 -0.6322357996  0.2591906744
## [146] -1.2442644354 -0.4295216849 -0.6012956061 -0.2666046035  0.2020034393
## [151]  1.3289238978  1.4259272819  1.3620753210 -0.7713557220  0.1226569167
## [156] -0.9686600663 -1.4680204754 -0.3461845617  0.7262443519  0.7352360331
## [161]  1.9391358235 -0.4077467286  0.2333486824  0.8605477752  0.9441682128
## [166]  1.1733216766 -1.1097460174 -0.5085365235  0.1922280646 -0.2556189579
## [171] -0.3189819666 -1.5305582475 -0.1027979128 -0.3784047944 -0.4139003189
## [176]  1.0054563402  0.4183960863  1.1172863248  0.9426594865  1.6797464363
## [181]  1.4467814506  2.5816050898  1.4120843743  1.6424688459  0.3635698141
## [186]  1.1028398582  2.2070336998  1.6119036231  1.8016172551  0.2566905276
## [191]  1.2341785606 -1.5131975128 -1.7985919608 -3.6919725607 -2.5458486583
## [196] -1.4960416420 -0.7403983695 -0.7571961238 -0.1603016025  1.3768511657
## [201]  1.3398408079  2.2041005425  2.3028273087  0.9421341274  0.8987884932
## [206]  1.7019690895 -2.0023942272 -1.1132007272  1.7625894950 -1.5649450191
## [211]  1.3306436751 -1.1944467094 -0.5425499034 -0.8368576901  0.5020182359
## [216]  0.2858115497 -2.3089419094 -1.4337098680 -0.8857248322 -1.2520379937
## [221] -0.5374332169 -1.2016867375  0.1849641988 -0.6792216656 -0.2385181208
## [226] -1.5372115969 -1.9813836327 -0.7160887685 -0.6723286910  0.1354161862
## [231] -1.1705183538  0.4013194768 -0.1330584065  2.0537282110  1.9588552681
## [236]  2.5151632283  1.4574347337  1.6344739973  3.0313260751  3.2015842648
## [241]  1.8910906862  3.5180968134  3.5352098463  1.5215641097  1.3033507636
## [246]  1.8289626578  1.0152030100  0.5580043396  0.9109794516  0.4161176122
## [251]  0.7701732172  1.0243457770  0.4629471262  2.3088735960 -0.2421535396
## [256]  1.6679559758  0.4085380936  0.8876103835  1.7824870110  0.0948950650
## [261]  1.1315195004 -0.7467429074 -0.0813903669 -1.6947790487 -0.0972479954
## [266] -0.7765347037 -1.5830454318 -0.5887958482 -0.8224746430 -1.5181223592
## [271]  0.1248683775 -0.6948623436 -0.6319318000  0.3098869089  0.4132612494
## [276] -0.1529102684 -0.4879447321 -1.1995455649 -0.3548623894 -0.4055887408
## [281]  0.2360627975 -0.0390954987 -0.5567111742 -0.2687581847 -0.8115092727
## [286] -0.8891446997  0.3183772907  1.0752590349  2.0633864637  1.4072009691
## [291]  0.2273615401  0.3642827445  0.7760965501  0.7933583066  0.6480641244
## [296]  0.4218363672  0.2091145687  0.6513462250
cor(yt2_ar,yt_2_ar)
## [1] 0.5100164

Korelasi antara \(Y_t\) dengan \(Y_{t-2}\) dari hasil simulasi sebesar 0.5100164.

plot(y=yt2_ar,x=yt_2_ar)

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

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

#Yt
yt3_ar <- ar[-c(1,2,3)]
yt3_ar
##   [1]  3.2941825568  1.5978135339  1.7535972732  1.3450053906 -0.5581342021
##   [6]  0.3261690081  1.5254340049  0.2396559060  0.9782860694  1.4280061994
##  [11]  0.9246097195  2.1477140618  1.0824346015  0.8689107540  0.4528603017
##  [16]  2.4489628800  0.9163907073 -0.0461928397 -0.4874501497 -0.1321727478
##  [21]  1.3451599187 -0.7320328580  0.3654710899  0.6776827513  1.7848402105
##  [26]  1.2970110168  0.1448946455 -0.8664208476 -1.0228538455 -0.3428852101
##  [31] -1.0140721643 -0.2913230970 -0.7732908559 -0.9282881060  1.2179080447
##  [36] -0.9365726180 -0.7440200072 -1.1757087785  0.8220666502  0.6268927577
##  [41] -0.5324756731 -0.7748702931 -0.0087541161  0.1136969301 -0.2827849295
##  [46]  0.8811245850  0.7757645000  1.8901856384  1.1570183945  1.1041794437
##  [51]  2.0521537420  0.9317553126  0.5339543378 -0.4631607973 -0.1673712310
##  [56]  0.6211143001 -0.0172205828 -0.5990201049 -1.1776015215 -1.0067865409
##  [61] -0.9837814718  0.3318411004 -0.7895722587  0.2265540591  0.8872056975
##  [66]  0.2891248820  3.2806598247  1.7431179347  0.3638828245  0.6144478598
##  [71]  0.4329707110  1.2733000647  2.3418840437  1.1900824926  1.9749275569
##  [76]  0.0520940933 -0.9455311177  0.9803676582  0.1876985183  1.4013626213
##  [81]  0.4547553092  0.7264361466 -0.8278470766  1.3054175689  0.5000733545
##  [86]  1.4869953924  0.7602406157 -0.3403685081 -0.1586993606  0.3942567023
##  [91]  2.0561737540  2.4881506489  2.1594135594  1.9683793594  1.8338159151
##  [96]  1.8356198584  0.0007075591 -1.0604699200 -1.2323549937  0.3687490214
## [101] -0.5961504203 -1.1563333613  0.5823544504 -2.4651580155 -0.6721029368
## [106] -0.8781344511 -1.0874180244 -0.6465909279 -2.1501403282 -0.5079376822
## [111] -0.5742794875  1.0982944086  1.1648745588  1.2916360209  1.1118011217
## [116]  1.3652222306 -0.6982953603 -1.0079190711 -3.0997989464 -0.1045110079
## [121] -0.8670011155 -1.5091448797 -1.7253033946 -0.9522386083 -0.9511508590
## [126]  0.4105727942 -1.0918847612 -0.1124743113  1.3263703587  1.9758860667
## [131]  1.1161327929  0.1466411658 -0.6167685819 -0.9129288077 -2.0152010753
## [136] -1.7921113090 -1.7171293502 -0.1367362503 -1.1334169855 -1.9648739708
## [141] -0.6322357996  0.2591906744 -1.2442644354 -0.4295216849 -0.6012956061
## [146] -0.2666046035  0.2020034393  1.3289238978  1.4259272819  1.3620753210
## [151] -0.7713557220  0.1226569167 -0.9686600663 -1.4680204754 -0.3461845617
## [156]  0.7262443519  0.7352360331  1.9391358235 -0.4077467286  0.2333486824
## [161]  0.8605477752  0.9441682128  1.1733216766 -1.1097460174 -0.5085365235
## [166]  0.1922280646 -0.2556189579 -0.3189819666 -1.5305582475 -0.1027979128
## [171] -0.3784047944 -0.4139003189  1.0054563402  0.4183960863  1.1172863248
## [176]  0.9426594865  1.6797464363  1.4467814506  2.5816050898  1.4120843743
## [181]  1.6424688459  0.3635698141  1.1028398582  2.2070336998  1.6119036231
## [186]  1.8016172551  0.2566905276  1.2341785606 -1.5131975128 -1.7985919608
## [191] -3.6919725607 -2.5458486583 -1.4960416420 -0.7403983695 -0.7571961238
## [196] -0.1603016025  1.3768511657  1.3398408079  2.2041005425  2.3028273087
## [201]  0.9421341274  0.8987884932  1.7019690895 -2.0023942272 -1.1132007272
## [206]  1.7625894950 -1.5649450191  1.3306436751 -1.1944467094 -0.5425499034
## [211] -0.8368576901  0.5020182359  0.2858115497 -2.3089419094 -1.4337098680
## [216] -0.8857248322 -1.2520379937 -0.5374332169 -1.2016867375  0.1849641988
## [221] -0.6792216656 -0.2385181208 -1.5372115969 -1.9813836327 -0.7160887685
## [226] -0.6723286910  0.1354161862 -1.1705183538  0.4013194768 -0.1330584065
## [231]  2.0537282110  1.9588552681  2.5151632283  1.4574347337  1.6344739973
## [236]  3.0313260751  3.2015842648  1.8910906862  3.5180968134  3.5352098463
## [241]  1.5215641097  1.3033507636  1.8289626578  1.0152030100  0.5580043396
## [246]  0.9109794516  0.4161176122  0.7701732172  1.0243457770  0.4629471262
## [251]  2.3088735960 -0.2421535396  1.6679559758  0.4085380936  0.8876103835
## [256]  1.7824870110  0.0948950650  1.1315195004 -0.7467429074 -0.0813903669
## [261] -1.6947790487 -0.0972479954 -0.7765347037 -1.5830454318 -0.5887958482
## [266] -0.8224746430 -1.5181223592  0.1248683775 -0.6948623436 -0.6319318000
## [271]  0.3098869089  0.4132612494 -0.1529102684 -0.4879447321 -1.1995455649
## [276] -0.3548623894 -0.4055887408  0.2360627975 -0.0390954987 -0.5567111742
## [281] -0.2687581847 -0.8115092727 -0.8891446997  0.3183772907  1.0752590349
## [286]  2.0633864637  1.4072009691  0.2273615401  0.3642827445  0.7760965501
## [291]  0.7933583066  0.6480641244  0.4218363672  0.2091145687  0.6513462250
## [296] -1.4709084168  0.6524046217
#Yt-2
yt_3_ar <- ar[-c(298,299,300)]
yt_3_ar
##   [1]  2.0000000000  3.0000000000  1.5777489568  3.2941825568  1.5978135339
##   [6]  1.7535972732  1.3450053906 -0.5581342021  0.3261690081  1.5254340049
##  [11]  0.2396559060  0.9782860694  1.4280061994  0.9246097195  2.1477140618
##  [16]  1.0824346015  0.8689107540  0.4528603017  2.4489628800  0.9163907073
##  [21] -0.0461928397 -0.4874501497 -0.1321727478  1.3451599187 -0.7320328580
##  [26]  0.3654710899  0.6776827513  1.7848402105  1.2970110168  0.1448946455
##  [31] -0.8664208476 -1.0228538455 -0.3428852101 -1.0140721643 -0.2913230970
##  [36] -0.7732908559 -0.9282881060  1.2179080447 -0.9365726180 -0.7440200072
##  [41] -1.1757087785  0.8220666502  0.6268927577 -0.5324756731 -0.7748702931
##  [46] -0.0087541161  0.1136969301 -0.2827849295  0.8811245850  0.7757645000
##  [51]  1.8901856384  1.1570183945  1.1041794437  2.0521537420  0.9317553126
##  [56]  0.5339543378 -0.4631607973 -0.1673712310  0.6211143001 -0.0172205828
##  [61] -0.5990201049 -1.1776015215 -1.0067865409 -0.9837814718  0.3318411004
##  [66] -0.7895722587  0.2265540591  0.8872056975  0.2891248820  3.2806598247
##  [71]  1.7431179347  0.3638828245  0.6144478598  0.4329707110  1.2733000647
##  [76]  2.3418840437  1.1900824926  1.9749275569  0.0520940933 -0.9455311177
##  [81]  0.9803676582  0.1876985183  1.4013626213  0.4547553092  0.7264361466
##  [86] -0.8278470766  1.3054175689  0.5000733545  1.4869953924  0.7602406157
##  [91] -0.3403685081 -0.1586993606  0.3942567023  2.0561737540  2.4881506489
##  [96]  2.1594135594  1.9683793594  1.8338159151  1.8356198584  0.0007075591
## [101] -1.0604699200 -1.2323549937  0.3687490214 -0.5961504203 -1.1563333613
## [106]  0.5823544504 -2.4651580155 -0.6721029368 -0.8781344511 -1.0874180244
## [111] -0.6465909279 -2.1501403282 -0.5079376822 -0.5742794875  1.0982944086
## [116]  1.1648745588  1.2916360209  1.1118011217  1.3652222306 -0.6982953603
## [121] -1.0079190711 -3.0997989464 -0.1045110079 -0.8670011155 -1.5091448797
## [126] -1.7253033946 -0.9522386083 -0.9511508590  0.4105727942 -1.0918847612
## [131] -0.1124743113  1.3263703587  1.9758860667  1.1161327929  0.1466411658
## [136] -0.6167685819 -0.9129288077 -2.0152010753 -1.7921113090 -1.7171293502
## [141] -0.1367362503 -1.1334169855 -1.9648739708 -0.6322357996  0.2591906744
## [146] -1.2442644354 -0.4295216849 -0.6012956061 -0.2666046035  0.2020034393
## [151]  1.3289238978  1.4259272819  1.3620753210 -0.7713557220  0.1226569167
## [156] -0.9686600663 -1.4680204754 -0.3461845617  0.7262443519  0.7352360331
## [161]  1.9391358235 -0.4077467286  0.2333486824  0.8605477752  0.9441682128
## [166]  1.1733216766 -1.1097460174 -0.5085365235  0.1922280646 -0.2556189579
## [171] -0.3189819666 -1.5305582475 -0.1027979128 -0.3784047944 -0.4139003189
## [176]  1.0054563402  0.4183960863  1.1172863248  0.9426594865  1.6797464363
## [181]  1.4467814506  2.5816050898  1.4120843743  1.6424688459  0.3635698141
## [186]  1.1028398582  2.2070336998  1.6119036231  1.8016172551  0.2566905276
## [191]  1.2341785606 -1.5131975128 -1.7985919608 -3.6919725607 -2.5458486583
## [196] -1.4960416420 -0.7403983695 -0.7571961238 -0.1603016025  1.3768511657
## [201]  1.3398408079  2.2041005425  2.3028273087  0.9421341274  0.8987884932
## [206]  1.7019690895 -2.0023942272 -1.1132007272  1.7625894950 -1.5649450191
## [211]  1.3306436751 -1.1944467094 -0.5425499034 -0.8368576901  0.5020182359
## [216]  0.2858115497 -2.3089419094 -1.4337098680 -0.8857248322 -1.2520379937
## [221] -0.5374332169 -1.2016867375  0.1849641988 -0.6792216656 -0.2385181208
## [226] -1.5372115969 -1.9813836327 -0.7160887685 -0.6723286910  0.1354161862
## [231] -1.1705183538  0.4013194768 -0.1330584065  2.0537282110  1.9588552681
## [236]  2.5151632283  1.4574347337  1.6344739973  3.0313260751  3.2015842648
## [241]  1.8910906862  3.5180968134  3.5352098463  1.5215641097  1.3033507636
## [246]  1.8289626578  1.0152030100  0.5580043396  0.9109794516  0.4161176122
## [251]  0.7701732172  1.0243457770  0.4629471262  2.3088735960 -0.2421535396
## [256]  1.6679559758  0.4085380936  0.8876103835  1.7824870110  0.0948950650
## [261]  1.1315195004 -0.7467429074 -0.0813903669 -1.6947790487 -0.0972479954
## [266] -0.7765347037 -1.5830454318 -0.5887958482 -0.8224746430 -1.5181223592
## [271]  0.1248683775 -0.6948623436 -0.6319318000  0.3098869089  0.4132612494
## [276] -0.1529102684 -0.4879447321 -1.1995455649 -0.3548623894 -0.4055887408
## [281]  0.2360627975 -0.0390954987 -0.5567111742 -0.2687581847 -0.8115092727
## [286] -0.8891446997  0.3183772907  1.0752590349  2.0633864637  1.4072009691
## [291]  0.2273615401  0.3642827445  0.7760965501  0.7933583066  0.6480641244
## [296]  0.4218363672  0.2091145687
cor(yt3_ar,yt_3_ar)
## [1] 0.3544178

Korelasi antara \(Y_t\) dengan \(Y_{t-2}\) dari hasil simulasi sebesar 0.3544178.

plot(y=yt3_ar,x=yt_3_ar)

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

Fungsi pembangkitan ARMA

Setelah mengetahui cara membangkitkan data berpola AR, MA, bagaimana cara melakukan pembangkitan data berpola tersebut yang lebih kompleks? Apakah dapat dibuat suatu fungsi yang fleksibel yang memungkinan pembangkitan dengan berapapun jumlah koefisien?

Pertama, lihat kembali bentuk umum data berpola ARMA.

\[ y_{t} = c + \sum_{i=1}^p \phi_{i}y_{t-i} + \sum_{j=1}^q e_{t-j}+ e_{t} \]

Jika koefisien dan white noise/nilai deret waktu sebelumnya dapat diekstrak dalam bentuk vektor, dapat dilakukan perkalian matriks untuk mencari nilai bagian AR dan MA:

set.seed(1002)
coefs <- c(0.5, 0.2)
e <- c(1, 2)

coefs %*% e
##      [,1]
## [1,]  0.9

Atau, dapat dilakukan perkalian elementwise yang dijumlahkan:

coefs * e
## [1] 0.5 0.4
sum(coefs * e)
## [1] 0.9

Dari prinsip ini, dapat dibuat fungsi umum untuk membangkitkan data ARMA. Input dari fungsi adalah jumlah data yang hendak dibangkitkan, koefisien MA, dan koefisien AR

arma.sim <- function(n, macoef, arcoef){
  manum <- length(macoef)
  arnum <- length(arcoef)
  stopifnot(manum < n & arnum < n)
  
  wn <- rnorm(n, sd = 0.5)
  init <- max(manum, arnum)

  arma <- wn[1:init]
  for(i in {init+1}:n){
   mastart <- i - manum
   maend <- i-1
   arstart <- i - arnum
   arend <- i-1
   arma[i] <- sum(arcoef * arma[arstart:arend]) + sum(macoef * wn[mastart:maend])  + wn[i]
   }
  return(arma)
}

Terlihat bahwa komponen \(\sum_{i=1}^q y_{t-1}\) disimulasikan melalui sum(arcoef * arma[arstart:arend]). Jadi, koefisien dikalikan dengan data \(y\) dari \(t-q\) di mana q adalah jumlah koefisien AR, sampai data \(t-1\). Lalu komponen \(\sum_{j=1}^q e_{t-j}\) disimulasikan melalui sum(macoef * wn[mastart:maend]). Koefisien dikalikan dengan white noise \(e\) dari \(t-p\), p jumlah koefisien MA, sampai \(t-1\).

# beberapa contoh pembangkitan melalui fungsi

ma2 <- arma.sim(300, c(0.4, 0.6), 0)
ar2 <- arma.sim(300, 0, c(0.5, 0.2))

par(mfrow = c(2, 2))
acf(ma2)
pacf(ma2)
acf(ar2)
pacf(ar2)

#contoh untuk ARMA
arma22 <- arma.sim(300, c(0.5, 0.2), c(0.4,0.6))

arma22 |> arima(c(2,0,2))
## 
## Call:
## arima(x = arma22, order = c(2, 0, 2))
## 
## Coefficients:
##          ar1     ar2     ma1     ma2  intercept
##       0.4759  0.4968  0.2355  0.4966    -1.2354
## s.e.  0.0781  0.0781  0.0710  0.0594     1.4949
## 
## sigma^2 estimated as 0.221:  log likelihood = -201.48,  aic = 414.96
set.seed(1002)
n = length(wn)
phi1 = 0.5
theta1 = 0.4
phi2=0.2
theta2=0.6

y.arma=c(1:n)
for (i in 3:n){y.arma[i] = phi1*y.arma[i-1] + theta1*wn[i-1] + phi2*y.arma[i-2] + theta2*wn[i-2]+wn[i]}
y.arma
##   [1]  1.00000000  2.00000000  0.90862746  2.80149851  1.78641982  2.74661744
##   [7]  1.77868181  0.09427805  0.19575431  0.77638931  0.63038217  1.67290811
##  [13]  1.72183406  1.89884364  3.23413555  2.38938496  2.50901726  1.38775726
##  [19]  3.10409024  2.13158481  1.76221492  0.02292257 -0.37086605  0.98762505
##  [25] -0.28256989  0.87266609  0.37924810  2.27107672  2.41441645  1.73220918
##  [31] -0.03208144 -1.28387673 -1.27293993 -1.76574716 -0.90329953 -1.49873333
##  [37] -1.41275656  0.38234517 -1.00659047 -0.38806296 -2.03538136 -0.09472111
##  [43]  0.25022383  0.21146781 -0.61176578 -0.63821880 -0.35475065 -0.24257674
##  [49]  0.83621497  0.95853285  2.72915817  2.37854523  2.70109352  3.18803300
##  [55]  2.41512177  2.13794664  0.30947255 -0.03226415  0.27626841  0.13080170
##  [61] -0.23324029 -1.42754232 -1.83723952 -2.09305724 -0.66574359 -1.24710484
##  [67]  0.10982971  0.50408389  0.77993954  3.92863315  3.22885676  3.02952587
##  [73]  1.80587173  0.89707953  1.81515705  3.11098649  2.89081614  3.85609097
##  [79]  1.55611461  0.26026305  0.63341166  0.01252691  2.06466262  1.12791947
##  [85]  1.74915584 -0.26441943  1.41014043  0.52553214  2.47027528  1.65508279
##  [91]  0.85592497  0.16129761  0.12655585  2.11865682  3.54717417  4.38837807
##  [97]  4.32503517  3.91681579  3.75017384  1.83524505  0.04118502 -1.65611843
## [103] -0.76047493 -1.18806381 -1.17354412 -0.23786915 -2.92601625 -1.30875347
## [109] -2.62607044 -1.84193357 -1.60843881 -3.06122751 -1.75594837 -2.06753876
## [115]  0.56382000  1.25962463  2.41656249  2.32738027  2.58492429  0.51487420
## [121] -0.46810388 -3.92194379 -1.94918203 -2.76868489 -1.91865193 -2.84916202
## [127] -2.54784689 -2.36722834 -0.54123071 -1.49834616 -0.30288454  0.62624978
## [133]  2.43894962  2.70230943  1.77862592  0.11156756 -1.07165154 -2.75043375
## [139] -3.14594902 -3.64309452 -1.89885478 -2.21838910 -2.50028252 -2.09823558
## [145] -1.17262803 -1.51992965 -0.77171305 -1.51966294 -0.76483586 -0.26541577
## [151]  1.24976251  2.07869890  2.72980057  0.62903078  0.63135982 -1.38241073
## [157] -1.78189035 -1.51458879 -0.29304176  0.81802304  2.66897685  0.80904922
## [163]  1.23373149  0.70923921  1.42839653  2.06731763 -0.07391642 -0.24844192
## [169] -0.67703416 -0.48384965 -0.30589271 -1.81152241 -0.90641039 -1.33785891
## [175] -0.62694098  0.61285334  0.57223843  1.88791856  1.64061167  2.72718203
## [181]  2.68427572  4.16816553  3.31279528  3.75626565  1.86780798  2.23374909
## [187]  2.86631153  3.15642102  3.77059892  1.94447960  2.41782512 -0.86551177
## [193] -1.66336383 -5.31932785 -5.10179286 -4.72956464 -2.86632422 -1.95098046
## [199] -0.90741907  0.85841285  1.79440031  3.56614757  3.98837201  3.18572538
## [205]  2.65733853  2.62676496 -0.78233350 -0.89297696  0.11587267 -1.52782966
## [211]  1.76221936 -1.60115625 -0.22194238 -1.77054568 -0.15825478 -0.01549577
## [217] -1.89340635 -2.18579970 -2.84457393 -2.46655385 -1.56968331 -2.16788282
## [223] -0.61817043 -1.32624803 -0.39922827 -2.04015184 -2.73937914 -2.43096918
## [229] -2.14759438 -0.56316855 -1.51974909  0.01436185 -0.67484163  2.24129653
## [235]  2.70051151  4.53094226  3.63881319  3.72654583  4.55957651  5.39479909
## [241]  4.99052004  6.19548365  6.07710298  5.04650614  4.03310232  3.26324143
## [247]  2.52879853  2.06146314  1.74330299  1.11531200  1.48320793  1.58208563
## [253]  1.33478937  3.10865991  0.95916417  2.95641872  0.93042836  2.05179921
## [259]  2.38265402  1.34045610  2.23896973 -0.23719807  0.29882417 -2.17538094
## [265] -0.82399383 -1.83230133 -1.95200811 -1.68793484 -2.00782024 -2.20038973
## [271] -0.97586535 -1.55578841 -0.83495571 -0.35980322  0.15805693  0.19832638
## [277] -0.30115209 -1.48646962 -1.12744745 -1.26726104 -0.13909013 -0.18802362
## [283] -0.43071170 -0.51489995 -1.25303925 -1.37500332 -0.52418615  0.66912313
## [289]  2.68451645  2.87771098  2.02827381  1.29954794  1.05822657  1.32236657
## [295]  1.43106538  1.15707700  0.76668759  0.98809387 -1.08490119  0.45484899

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

set.seed(1002)
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]  2.26962428  2.41330919  1.73136506 -0.03272495 -1.28436730 -1.27331392
##   [7] -1.76603227 -0.90351688 -1.49889903 -1.41288288  0.38224887 -1.00666389
##  [13] -0.38811892 -2.03542402 -0.09475364  0.25019903  0.21144890 -0.61178019
##  [19] -0.63822978 -0.35475902 -0.24258312  0.83621010  0.95852914  2.72915534
##  [25]  2.37854308  2.70109188  3.18803175  2.41512081  2.13794591  0.30947200
##  [31] -0.03226457  0.27626809  0.13080145 -0.23324048 -1.42754246 -1.83723963
##  [37] -2.09305732 -0.66574366 -1.24710489  0.10982967  0.50408386  0.77993951
##  [43]  3.92863313  3.22885675  3.02952586  1.80587172  0.89707953  1.81515705
##  [49]  3.11098648  2.89081614  3.85609097  1.55611461  0.26026305  0.63341166
##  [55]  0.01252691  2.06466262  1.12791947  1.74915584 -0.26441943  1.41014043
##  [61]  0.52553214  2.47027528  1.65508279  0.85592497  0.16129761  0.12655585
##  [67]  2.11865682  3.54717417  4.38837807  4.32503517  3.91681579  3.75017384
##  [73]  1.83524505  0.04118502 -1.65611843 -0.76047493 -1.18806381 -1.17354412
##  [79] -0.23786915 -2.92601625 -1.30875347 -2.62607044 -1.84193357 -1.60843881
##  [85] -3.06122751 -1.75594837 -2.06753876  0.56382000  1.25962463  2.41656249
##  [91]  2.32738027  2.58492429  0.51487420 -0.46810388 -3.92194379 -1.94918203
##  [97] -2.76868489 -1.91865193 -2.84916202 -2.54784689 -2.36722834 -0.54123071
## [103] -1.49834616 -0.30288454  0.62624978  2.43894962  2.70230943  1.77862592
## [109]  0.11156756 -1.07165154 -2.75043375 -3.14594902 -3.64309452 -1.89885478
## [115] -2.21838910 -2.50028252 -2.09823558 -1.17262803 -1.51992965 -0.77171305
## [121] -1.51966294 -0.76483586 -0.26541577  1.24976251  2.07869890  2.72980057
## [127]  0.62903078  0.63135982 -1.38241073 -1.78189035 -1.51458879 -0.29304176
## [133]  0.81802304  2.66897685  0.80904922  1.23373149  0.70923921  1.42839653
## [139]  2.06731763 -0.07391642 -0.24844192 -0.67703416 -0.48384965 -0.30589271
## [145] -1.81152241 -0.90641039 -1.33785891 -0.62694098  0.61285334  0.57223843
## [151]  1.88791856  1.64061167  2.72718203  2.68427572  4.16816553  3.31279528
## [157]  3.75626565  1.86780798  2.23374909  2.86631153  3.15642102  3.77059892
## [163]  1.94447960  2.41782512 -0.86551177 -1.66336383 -5.31932785 -5.10179286
## [169] -4.72956464 -2.86632422 -1.95098046 -0.90741907  0.85841285  1.79440031
## [175]  3.56614757  3.98837201  3.18572538  2.65733853  2.62676496 -0.78233350
## [181] -0.89297696  0.11587267 -1.52782966  1.76221936 -1.60115625 -0.22194238
## [187] -1.77054568 -0.15825478 -0.01549577 -1.89340635 -2.18579970 -2.84457393
## [193] -2.46655385 -1.56968331 -2.16788282 -0.61817043 -1.32624803 -0.39922827
## [199] -2.04015184 -2.73937914 -2.43096918 -2.14759438 -0.56316855 -1.51974909
## [205]  0.01436185 -0.67484163  2.24129653  2.70051151  4.53094226  3.63881319
## [211]  3.72654583  4.55957651  5.39479909  4.99052004  6.19548365  6.07710298
## [217]  5.04650614  4.03310232  3.26324143  2.52879853  2.06146314  1.74330299
## [223]  1.11531200  1.48320793  1.58208563  1.33478937  3.10865991  0.95916417
## [229]  2.95641872  0.93042836  2.05179921  2.38265402  1.34045610  2.23896973
## [235] -0.23719807  0.29882417 -2.17538094 -0.82399383 -1.83230133 -1.95200811
## [241] -1.68793484 -2.00782024 -2.20038973 -0.97586535 -1.55578841 -0.83495571
## [247] -0.35980322  0.15805693  0.19832638 -0.30115209 -1.48646962 -1.12744745
## [253] -1.26726104 -0.13909013 -0.18802362 -0.43071170 -0.51489995 -1.25303925
## [259] -1.37500332 -0.52418615  0.66912313  2.68451645  2.87771098  2.02827381
## [265]  1.29954794  1.05822657  1.32236657  1.43106538  1.15707700  0.76668759
## [271]  0.98809387 -1.08490119  0.45484899 -1.00423828  1.70169503  1.07265235
## [277]  0.84904993 -0.55717178 -0.28437368 -1.61833190 -0.46212695 -0.85734611
## [283]  1.32334789  1.03077209  1.81284188  1.60898453  2.49065180  3.57380175
## [289]  4.45900946  3.91123613  2.04864728  1.69284019 -0.37815901  1.50104762
## [295]  0.36947578  1.42342958  0.06245159  1.99546624  1.08846122  1.36826417

Karakteristik ARMA(2,2)

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(2, 2))

Berdasarkan plot ACF tersebut, terlihat bahwa model ARMA(2,2) 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(2, 2))

Berdasarkan plot PACF tersebut, terlihat bahwa model ARMA(2,2) hasil simulasi memiliki plot PACF yang cuts off, tidak 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 o o o o o  o  o  o 
## 1 x x o o x o o o o o o  o  o  o 
## 2 x x x o x o o o o o o  o  o  o 
## 3 o x x x x o o o o o o  o  o  o 
## 4 x x x o x x o o o o o  o  o  o 
## 5 x x x x x x o o o o o  o  o  o 
## 6 x x o x o o o o o o o  o  o  o 
## 7 x x o x o o o x 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 o o o o o o  o  o  o 
## 1 x x o o x o o o o o o  o  o  o 
## 2 x x x o o o o o o o o  o  o  o 
## 3 o x x x x o o o o o o  o  o  o 
## 4 x x x o 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 x x x o o o o o o  o  o  o 
## 7 x x x o x x o o o o o  o  o  o

Berdasarkan pola segitiga nol pada plot EACF, tidak terlihat bahwa segitiga nol berada pada ordo AR(2) dan ordo MA(2)

Scatterplot Antar Lag

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

#Yt
yt1_arma <- arma22[-1]
yt1_arma
##   [1]  2.41330919  1.73136506 -0.03272495 -1.28436730 -1.27331392 -1.76603227
##   [7] -0.90351688 -1.49889903 -1.41288288  0.38224887 -1.00666389 -0.38811892
##  [13] -2.03542402 -0.09475364  0.25019903  0.21144890 -0.61178019 -0.63822978
##  [19] -0.35475902 -0.24258312  0.83621010  0.95852914  2.72915534  2.37854308
##  [25]  2.70109188  3.18803175  2.41512081  2.13794591  0.30947200 -0.03226457
##  [31]  0.27626809  0.13080145 -0.23324048 -1.42754246 -1.83723963 -2.09305732
##  [37] -0.66574366 -1.24710489  0.10982967  0.50408386  0.77993951  3.92863313
##  [43]  3.22885675  3.02952586  1.80587172  0.89707953  1.81515705  3.11098648
##  [49]  2.89081614  3.85609097  1.55611461  0.26026305  0.63341166  0.01252691
##  [55]  2.06466262  1.12791947  1.74915584 -0.26441943  1.41014043  0.52553214
##  [61]  2.47027528  1.65508279  0.85592497  0.16129761  0.12655585  2.11865682
##  [67]  3.54717417  4.38837807  4.32503517  3.91681579  3.75017384  1.83524505
##  [73]  0.04118502 -1.65611843 -0.76047493 -1.18806381 -1.17354412 -0.23786915
##  [79] -2.92601625 -1.30875347 -2.62607044 -1.84193357 -1.60843881 -3.06122751
##  [85] -1.75594837 -2.06753876  0.56382000  1.25962463  2.41656249  2.32738027
##  [91]  2.58492429  0.51487420 -0.46810388 -3.92194379 -1.94918203 -2.76868489
##  [97] -1.91865193 -2.84916202 -2.54784689 -2.36722834 -0.54123071 -1.49834616
## [103] -0.30288454  0.62624978  2.43894962  2.70230943  1.77862592  0.11156756
## [109] -1.07165154 -2.75043375 -3.14594902 -3.64309452 -1.89885478 -2.21838910
## [115] -2.50028252 -2.09823558 -1.17262803 -1.51992965 -0.77171305 -1.51966294
## [121] -0.76483586 -0.26541577  1.24976251  2.07869890  2.72980057  0.62903078
## [127]  0.63135982 -1.38241073 -1.78189035 -1.51458879 -0.29304176  0.81802304
## [133]  2.66897685  0.80904922  1.23373149  0.70923921  1.42839653  2.06731763
## [139] -0.07391642 -0.24844192 -0.67703416 -0.48384965 -0.30589271 -1.81152241
## [145] -0.90641039 -1.33785891 -0.62694098  0.61285334  0.57223843  1.88791856
## [151]  1.64061167  2.72718203  2.68427572  4.16816553  3.31279528  3.75626565
## [157]  1.86780798  2.23374909  2.86631153  3.15642102  3.77059892  1.94447960
## [163]  2.41782512 -0.86551177 -1.66336383 -5.31932785 -5.10179286 -4.72956464
## [169] -2.86632422 -1.95098046 -0.90741907  0.85841285  1.79440031  3.56614757
## [175]  3.98837201  3.18572538  2.65733853  2.62676496 -0.78233350 -0.89297696
## [181]  0.11587267 -1.52782966  1.76221936 -1.60115625 -0.22194238 -1.77054568
## [187] -0.15825478 -0.01549577 -1.89340635 -2.18579970 -2.84457393 -2.46655385
## [193] -1.56968331 -2.16788282 -0.61817043 -1.32624803 -0.39922827 -2.04015184
## [199] -2.73937914 -2.43096918 -2.14759438 -0.56316855 -1.51974909  0.01436185
## [205] -0.67484163  2.24129653  2.70051151  4.53094226  3.63881319  3.72654583
## [211]  4.55957651  5.39479909  4.99052004  6.19548365  6.07710298  5.04650614
## [217]  4.03310232  3.26324143  2.52879853  2.06146314  1.74330299  1.11531200
## [223]  1.48320793  1.58208563  1.33478937  3.10865991  0.95916417  2.95641872
## [229]  0.93042836  2.05179921  2.38265402  1.34045610  2.23896973 -0.23719807
## [235]  0.29882417 -2.17538094 -0.82399383 -1.83230133 -1.95200811 -1.68793484
## [241] -2.00782024 -2.20038973 -0.97586535 -1.55578841 -0.83495571 -0.35980322
## [247]  0.15805693  0.19832638 -0.30115209 -1.48646962 -1.12744745 -1.26726104
## [253] -0.13909013 -0.18802362 -0.43071170 -0.51489995 -1.25303925 -1.37500332
## [259] -0.52418615  0.66912313  2.68451645  2.87771098  2.02827381  1.29954794
## [265]  1.05822657  1.32236657  1.43106538  1.15707700  0.76668759  0.98809387
## [271] -1.08490119  0.45484899 -1.00423828  1.70169503  1.07265235  0.84904993
## [277] -0.55717178 -0.28437368 -1.61833190 -0.46212695 -0.85734611  1.32334789
## [283]  1.03077209  1.81284188  1.60898453  2.49065180  3.57380175  4.45900946
## [289]  3.91123613  2.04864728  1.69284019 -0.37815901  1.50104762  0.36947578
## [295]  1.42342958  0.06245159  1.99546624  1.08846122  1.36826417
#Yt-1
yt_1_arma <- arma22[-300]
yt_1_arma
##   [1]  2.26962428  2.41330919  1.73136506 -0.03272495 -1.28436730 -1.27331392
##   [7] -1.76603227 -0.90351688 -1.49889903 -1.41288288  0.38224887 -1.00666389
##  [13] -0.38811892 -2.03542402 -0.09475364  0.25019903  0.21144890 -0.61178019
##  [19] -0.63822978 -0.35475902 -0.24258312  0.83621010  0.95852914  2.72915534
##  [25]  2.37854308  2.70109188  3.18803175  2.41512081  2.13794591  0.30947200
##  [31] -0.03226457  0.27626809  0.13080145 -0.23324048 -1.42754246 -1.83723963
##  [37] -2.09305732 -0.66574366 -1.24710489  0.10982967  0.50408386  0.77993951
##  [43]  3.92863313  3.22885675  3.02952586  1.80587172  0.89707953  1.81515705
##  [49]  3.11098648  2.89081614  3.85609097  1.55611461  0.26026305  0.63341166
##  [55]  0.01252691  2.06466262  1.12791947  1.74915584 -0.26441943  1.41014043
##  [61]  0.52553214  2.47027528  1.65508279  0.85592497  0.16129761  0.12655585
##  [67]  2.11865682  3.54717417  4.38837807  4.32503517  3.91681579  3.75017384
##  [73]  1.83524505  0.04118502 -1.65611843 -0.76047493 -1.18806381 -1.17354412
##  [79] -0.23786915 -2.92601625 -1.30875347 -2.62607044 -1.84193357 -1.60843881
##  [85] -3.06122751 -1.75594837 -2.06753876  0.56382000  1.25962463  2.41656249
##  [91]  2.32738027  2.58492429  0.51487420 -0.46810388 -3.92194379 -1.94918203
##  [97] -2.76868489 -1.91865193 -2.84916202 -2.54784689 -2.36722834 -0.54123071
## [103] -1.49834616 -0.30288454  0.62624978  2.43894962  2.70230943  1.77862592
## [109]  0.11156756 -1.07165154 -2.75043375 -3.14594902 -3.64309452 -1.89885478
## [115] -2.21838910 -2.50028252 -2.09823558 -1.17262803 -1.51992965 -0.77171305
## [121] -1.51966294 -0.76483586 -0.26541577  1.24976251  2.07869890  2.72980057
## [127]  0.62903078  0.63135982 -1.38241073 -1.78189035 -1.51458879 -0.29304176
## [133]  0.81802304  2.66897685  0.80904922  1.23373149  0.70923921  1.42839653
## [139]  2.06731763 -0.07391642 -0.24844192 -0.67703416 -0.48384965 -0.30589271
## [145] -1.81152241 -0.90641039 -1.33785891 -0.62694098  0.61285334  0.57223843
## [151]  1.88791856  1.64061167  2.72718203  2.68427572  4.16816553  3.31279528
## [157]  3.75626565  1.86780798  2.23374909  2.86631153  3.15642102  3.77059892
## [163]  1.94447960  2.41782512 -0.86551177 -1.66336383 -5.31932785 -5.10179286
## [169] -4.72956464 -2.86632422 -1.95098046 -0.90741907  0.85841285  1.79440031
## [175]  3.56614757  3.98837201  3.18572538  2.65733853  2.62676496 -0.78233350
## [181] -0.89297696  0.11587267 -1.52782966  1.76221936 -1.60115625 -0.22194238
## [187] -1.77054568 -0.15825478 -0.01549577 -1.89340635 -2.18579970 -2.84457393
## [193] -2.46655385 -1.56968331 -2.16788282 -0.61817043 -1.32624803 -0.39922827
## [199] -2.04015184 -2.73937914 -2.43096918 -2.14759438 -0.56316855 -1.51974909
## [205]  0.01436185 -0.67484163  2.24129653  2.70051151  4.53094226  3.63881319
## [211]  3.72654583  4.55957651  5.39479909  4.99052004  6.19548365  6.07710298
## [217]  5.04650614  4.03310232  3.26324143  2.52879853  2.06146314  1.74330299
## [223]  1.11531200  1.48320793  1.58208563  1.33478937  3.10865991  0.95916417
## [229]  2.95641872  0.93042836  2.05179921  2.38265402  1.34045610  2.23896973
## [235] -0.23719807  0.29882417 -2.17538094 -0.82399383 -1.83230133 -1.95200811
## [241] -1.68793484 -2.00782024 -2.20038973 -0.97586535 -1.55578841 -0.83495571
## [247] -0.35980322  0.15805693  0.19832638 -0.30115209 -1.48646962 -1.12744745
## [253] -1.26726104 -0.13909013 -0.18802362 -0.43071170 -0.51489995 -1.25303925
## [259] -1.37500332 -0.52418615  0.66912313  2.68451645  2.87771098  2.02827381
## [265]  1.29954794  1.05822657  1.32236657  1.43106538  1.15707700  0.76668759
## [271]  0.98809387 -1.08490119  0.45484899 -1.00423828  1.70169503  1.07265235
## [277]  0.84904993 -0.55717178 -0.28437368 -1.61833190 -0.46212695 -0.85734611
## [283]  1.32334789  1.03077209  1.81284188  1.60898453  2.49065180  3.57380175
## [289]  4.45900946  3.91123613  2.04864728  1.69284019 -0.37815901  1.50104762
## [295]  0.36947578  1.42342958  0.06245159  1.99546624  1.08846122
plot(y=yt1_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(yt1_arma,yt_1_arma)
## [1] 0.8277724

Korelasi antara \(Y_t\) dengan \(Y_{t-1}\) dari hasil simulasi sebesar 0.8277724

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

#Yt
yt2_arma <- arma22[-c(1,2)]
yt2_arma
##   [1]  1.73136506 -0.03272495 -1.28436730 -1.27331392 -1.76603227 -0.90351688
##   [7] -1.49889903 -1.41288288  0.38224887 -1.00666389 -0.38811892 -2.03542402
##  [13] -0.09475364  0.25019903  0.21144890 -0.61178019 -0.63822978 -0.35475902
##  [19] -0.24258312  0.83621010  0.95852914  2.72915534  2.37854308  2.70109188
##  [25]  3.18803175  2.41512081  2.13794591  0.30947200 -0.03226457  0.27626809
##  [31]  0.13080145 -0.23324048 -1.42754246 -1.83723963 -2.09305732 -0.66574366
##  [37] -1.24710489  0.10982967  0.50408386  0.77993951  3.92863313  3.22885675
##  [43]  3.02952586  1.80587172  0.89707953  1.81515705  3.11098648  2.89081614
##  [49]  3.85609097  1.55611461  0.26026305  0.63341166  0.01252691  2.06466262
##  [55]  1.12791947  1.74915584 -0.26441943  1.41014043  0.52553214  2.47027528
##  [61]  1.65508279  0.85592497  0.16129761  0.12655585  2.11865682  3.54717417
##  [67]  4.38837807  4.32503517  3.91681579  3.75017384  1.83524505  0.04118502
##  [73] -1.65611843 -0.76047493 -1.18806381 -1.17354412 -0.23786915 -2.92601625
##  [79] -1.30875347 -2.62607044 -1.84193357 -1.60843881 -3.06122751 -1.75594837
##  [85] -2.06753876  0.56382000  1.25962463  2.41656249  2.32738027  2.58492429
##  [91]  0.51487420 -0.46810388 -3.92194379 -1.94918203 -2.76868489 -1.91865193
##  [97] -2.84916202 -2.54784689 -2.36722834 -0.54123071 -1.49834616 -0.30288454
## [103]  0.62624978  2.43894962  2.70230943  1.77862592  0.11156756 -1.07165154
## [109] -2.75043375 -3.14594902 -3.64309452 -1.89885478 -2.21838910 -2.50028252
## [115] -2.09823558 -1.17262803 -1.51992965 -0.77171305 -1.51966294 -0.76483586
## [121] -0.26541577  1.24976251  2.07869890  2.72980057  0.62903078  0.63135982
## [127] -1.38241073 -1.78189035 -1.51458879 -0.29304176  0.81802304  2.66897685
## [133]  0.80904922  1.23373149  0.70923921  1.42839653  2.06731763 -0.07391642
## [139] -0.24844192 -0.67703416 -0.48384965 -0.30589271 -1.81152241 -0.90641039
## [145] -1.33785891 -0.62694098  0.61285334  0.57223843  1.88791856  1.64061167
## [151]  2.72718203  2.68427572  4.16816553  3.31279528  3.75626565  1.86780798
## [157]  2.23374909  2.86631153  3.15642102  3.77059892  1.94447960  2.41782512
## [163] -0.86551177 -1.66336383 -5.31932785 -5.10179286 -4.72956464 -2.86632422
## [169] -1.95098046 -0.90741907  0.85841285  1.79440031  3.56614757  3.98837201
## [175]  3.18572538  2.65733853  2.62676496 -0.78233350 -0.89297696  0.11587267
## [181] -1.52782966  1.76221936 -1.60115625 -0.22194238 -1.77054568 -0.15825478
## [187] -0.01549577 -1.89340635 -2.18579970 -2.84457393 -2.46655385 -1.56968331
## [193] -2.16788282 -0.61817043 -1.32624803 -0.39922827 -2.04015184 -2.73937914
## [199] -2.43096918 -2.14759438 -0.56316855 -1.51974909  0.01436185 -0.67484163
## [205]  2.24129653  2.70051151  4.53094226  3.63881319  3.72654583  4.55957651
## [211]  5.39479909  4.99052004  6.19548365  6.07710298  5.04650614  4.03310232
## [217]  3.26324143  2.52879853  2.06146314  1.74330299  1.11531200  1.48320793
## [223]  1.58208563  1.33478937  3.10865991  0.95916417  2.95641872  0.93042836
## [229]  2.05179921  2.38265402  1.34045610  2.23896973 -0.23719807  0.29882417
## [235] -2.17538094 -0.82399383 -1.83230133 -1.95200811 -1.68793484 -2.00782024
## [241] -2.20038973 -0.97586535 -1.55578841 -0.83495571 -0.35980322  0.15805693
## [247]  0.19832638 -0.30115209 -1.48646962 -1.12744745 -1.26726104 -0.13909013
## [253] -0.18802362 -0.43071170 -0.51489995 -1.25303925 -1.37500332 -0.52418615
## [259]  0.66912313  2.68451645  2.87771098  2.02827381  1.29954794  1.05822657
## [265]  1.32236657  1.43106538  1.15707700  0.76668759  0.98809387 -1.08490119
## [271]  0.45484899 -1.00423828  1.70169503  1.07265235  0.84904993 -0.55717178
## [277] -0.28437368 -1.61833190 -0.46212695 -0.85734611  1.32334789  1.03077209
## [283]  1.81284188  1.60898453  2.49065180  3.57380175  4.45900946  3.91123613
## [289]  2.04864728  1.69284019 -0.37815901  1.50104762  0.36947578  1.42342958
## [295]  0.06245159  1.99546624  1.08846122  1.36826417
#Yt-1
yt_2_arma <- arma22[-c(299,300)]
yt_2_arma
##   [1]  2.26962428  2.41330919  1.73136506 -0.03272495 -1.28436730 -1.27331392
##   [7] -1.76603227 -0.90351688 -1.49889903 -1.41288288  0.38224887 -1.00666389
##  [13] -0.38811892 -2.03542402 -0.09475364  0.25019903  0.21144890 -0.61178019
##  [19] -0.63822978 -0.35475902 -0.24258312  0.83621010  0.95852914  2.72915534
##  [25]  2.37854308  2.70109188  3.18803175  2.41512081  2.13794591  0.30947200
##  [31] -0.03226457  0.27626809  0.13080145 -0.23324048 -1.42754246 -1.83723963
##  [37] -2.09305732 -0.66574366 -1.24710489  0.10982967  0.50408386  0.77993951
##  [43]  3.92863313  3.22885675  3.02952586  1.80587172  0.89707953  1.81515705
##  [49]  3.11098648  2.89081614  3.85609097  1.55611461  0.26026305  0.63341166
##  [55]  0.01252691  2.06466262  1.12791947  1.74915584 -0.26441943  1.41014043
##  [61]  0.52553214  2.47027528  1.65508279  0.85592497  0.16129761  0.12655585
##  [67]  2.11865682  3.54717417  4.38837807  4.32503517  3.91681579  3.75017384
##  [73]  1.83524505  0.04118502 -1.65611843 -0.76047493 -1.18806381 -1.17354412
##  [79] -0.23786915 -2.92601625 -1.30875347 -2.62607044 -1.84193357 -1.60843881
##  [85] -3.06122751 -1.75594837 -2.06753876  0.56382000  1.25962463  2.41656249
##  [91]  2.32738027  2.58492429  0.51487420 -0.46810388 -3.92194379 -1.94918203
##  [97] -2.76868489 -1.91865193 -2.84916202 -2.54784689 -2.36722834 -0.54123071
## [103] -1.49834616 -0.30288454  0.62624978  2.43894962  2.70230943  1.77862592
## [109]  0.11156756 -1.07165154 -2.75043375 -3.14594902 -3.64309452 -1.89885478
## [115] -2.21838910 -2.50028252 -2.09823558 -1.17262803 -1.51992965 -0.77171305
## [121] -1.51966294 -0.76483586 -0.26541577  1.24976251  2.07869890  2.72980057
## [127]  0.62903078  0.63135982 -1.38241073 -1.78189035 -1.51458879 -0.29304176
## [133]  0.81802304  2.66897685  0.80904922  1.23373149  0.70923921  1.42839653
## [139]  2.06731763 -0.07391642 -0.24844192 -0.67703416 -0.48384965 -0.30589271
## [145] -1.81152241 -0.90641039 -1.33785891 -0.62694098  0.61285334  0.57223843
## [151]  1.88791856  1.64061167  2.72718203  2.68427572  4.16816553  3.31279528
## [157]  3.75626565  1.86780798  2.23374909  2.86631153  3.15642102  3.77059892
## [163]  1.94447960  2.41782512 -0.86551177 -1.66336383 -5.31932785 -5.10179286
## [169] -4.72956464 -2.86632422 -1.95098046 -0.90741907  0.85841285  1.79440031
## [175]  3.56614757  3.98837201  3.18572538  2.65733853  2.62676496 -0.78233350
## [181] -0.89297696  0.11587267 -1.52782966  1.76221936 -1.60115625 -0.22194238
## [187] -1.77054568 -0.15825478 -0.01549577 -1.89340635 -2.18579970 -2.84457393
## [193] -2.46655385 -1.56968331 -2.16788282 -0.61817043 -1.32624803 -0.39922827
## [199] -2.04015184 -2.73937914 -2.43096918 -2.14759438 -0.56316855 -1.51974909
## [205]  0.01436185 -0.67484163  2.24129653  2.70051151  4.53094226  3.63881319
## [211]  3.72654583  4.55957651  5.39479909  4.99052004  6.19548365  6.07710298
## [217]  5.04650614  4.03310232  3.26324143  2.52879853  2.06146314  1.74330299
## [223]  1.11531200  1.48320793  1.58208563  1.33478937  3.10865991  0.95916417
## [229]  2.95641872  0.93042836  2.05179921  2.38265402  1.34045610  2.23896973
## [235] -0.23719807  0.29882417 -2.17538094 -0.82399383 -1.83230133 -1.95200811
## [241] -1.68793484 -2.00782024 -2.20038973 -0.97586535 -1.55578841 -0.83495571
## [247] -0.35980322  0.15805693  0.19832638 -0.30115209 -1.48646962 -1.12744745
## [253] -1.26726104 -0.13909013 -0.18802362 -0.43071170 -0.51489995 -1.25303925
## [259] -1.37500332 -0.52418615  0.66912313  2.68451645  2.87771098  2.02827381
## [265]  1.29954794  1.05822657  1.32236657  1.43106538  1.15707700  0.76668759
## [271]  0.98809387 -1.08490119  0.45484899 -1.00423828  1.70169503  1.07265235
## [277]  0.84904993 -0.55717178 -0.28437368 -1.61833190 -0.46212695 -0.85734611
## [283]  1.32334789  1.03077209  1.81284188  1.60898453  2.49065180  3.57380175
## [289]  4.45900946  3.91123613  2.04864728  1.69284019 -0.37815901  1.50104762
## [295]  0.36947578  1.42342958  0.06245159  1.99546624
plot(y=yt2_arma,x=yt_2_arma)

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

cor(yt2_arma,yt_2_arma)
## [1] 0.7273334

Korelasi antara \(Y_t\) dengan \(Y_{t-2}\) dari hasil simulasi sebesar 0.7273334

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

#Yt
yt3_arma <- arma22[-c(1,2,3)]
yt3_arma
##   [1] -0.03272495 -1.28436730 -1.27331392 -1.76603227 -0.90351688 -1.49889903
##   [7] -1.41288288  0.38224887 -1.00666389 -0.38811892 -2.03542402 -0.09475364
##  [13]  0.25019903  0.21144890 -0.61178019 -0.63822978 -0.35475902 -0.24258312
##  [19]  0.83621010  0.95852914  2.72915534  2.37854308  2.70109188  3.18803175
##  [25]  2.41512081  2.13794591  0.30947200 -0.03226457  0.27626809  0.13080145
##  [31] -0.23324048 -1.42754246 -1.83723963 -2.09305732 -0.66574366 -1.24710489
##  [37]  0.10982967  0.50408386  0.77993951  3.92863313  3.22885675  3.02952586
##  [43]  1.80587172  0.89707953  1.81515705  3.11098648  2.89081614  3.85609097
##  [49]  1.55611461  0.26026305  0.63341166  0.01252691  2.06466262  1.12791947
##  [55]  1.74915584 -0.26441943  1.41014043  0.52553214  2.47027528  1.65508279
##  [61]  0.85592497  0.16129761  0.12655585  2.11865682  3.54717417  4.38837807
##  [67]  4.32503517  3.91681579  3.75017384  1.83524505  0.04118502 -1.65611843
##  [73] -0.76047493 -1.18806381 -1.17354412 -0.23786915 -2.92601625 -1.30875347
##  [79] -2.62607044 -1.84193357 -1.60843881 -3.06122751 -1.75594837 -2.06753876
##  [85]  0.56382000  1.25962463  2.41656249  2.32738027  2.58492429  0.51487420
##  [91] -0.46810388 -3.92194379 -1.94918203 -2.76868489 -1.91865193 -2.84916202
##  [97] -2.54784689 -2.36722834 -0.54123071 -1.49834616 -0.30288454  0.62624978
## [103]  2.43894962  2.70230943  1.77862592  0.11156756 -1.07165154 -2.75043375
## [109] -3.14594902 -3.64309452 -1.89885478 -2.21838910 -2.50028252 -2.09823558
## [115] -1.17262803 -1.51992965 -0.77171305 -1.51966294 -0.76483586 -0.26541577
## [121]  1.24976251  2.07869890  2.72980057  0.62903078  0.63135982 -1.38241073
## [127] -1.78189035 -1.51458879 -0.29304176  0.81802304  2.66897685  0.80904922
## [133]  1.23373149  0.70923921  1.42839653  2.06731763 -0.07391642 -0.24844192
## [139] -0.67703416 -0.48384965 -0.30589271 -1.81152241 -0.90641039 -1.33785891
## [145] -0.62694098  0.61285334  0.57223843  1.88791856  1.64061167  2.72718203
## [151]  2.68427572  4.16816553  3.31279528  3.75626565  1.86780798  2.23374909
## [157]  2.86631153  3.15642102  3.77059892  1.94447960  2.41782512 -0.86551177
## [163] -1.66336383 -5.31932785 -5.10179286 -4.72956464 -2.86632422 -1.95098046
## [169] -0.90741907  0.85841285  1.79440031  3.56614757  3.98837201  3.18572538
## [175]  2.65733853  2.62676496 -0.78233350 -0.89297696  0.11587267 -1.52782966
## [181]  1.76221936 -1.60115625 -0.22194238 -1.77054568 -0.15825478 -0.01549577
## [187] -1.89340635 -2.18579970 -2.84457393 -2.46655385 -1.56968331 -2.16788282
## [193] -0.61817043 -1.32624803 -0.39922827 -2.04015184 -2.73937914 -2.43096918
## [199] -2.14759438 -0.56316855 -1.51974909  0.01436185 -0.67484163  2.24129653
## [205]  2.70051151  4.53094226  3.63881319  3.72654583  4.55957651  5.39479909
## [211]  4.99052004  6.19548365  6.07710298  5.04650614  4.03310232  3.26324143
## [217]  2.52879853  2.06146314  1.74330299  1.11531200  1.48320793  1.58208563
## [223]  1.33478937  3.10865991  0.95916417  2.95641872  0.93042836  2.05179921
## [229]  2.38265402  1.34045610  2.23896973 -0.23719807  0.29882417 -2.17538094
## [235] -0.82399383 -1.83230133 -1.95200811 -1.68793484 -2.00782024 -2.20038973
## [241] -0.97586535 -1.55578841 -0.83495571 -0.35980322  0.15805693  0.19832638
## [247] -0.30115209 -1.48646962 -1.12744745 -1.26726104 -0.13909013 -0.18802362
## [253] -0.43071170 -0.51489995 -1.25303925 -1.37500332 -0.52418615  0.66912313
## [259]  2.68451645  2.87771098  2.02827381  1.29954794  1.05822657  1.32236657
## [265]  1.43106538  1.15707700  0.76668759  0.98809387 -1.08490119  0.45484899
## [271] -1.00423828  1.70169503  1.07265235  0.84904993 -0.55717178 -0.28437368
## [277] -1.61833190 -0.46212695 -0.85734611  1.32334789  1.03077209  1.81284188
## [283]  1.60898453  2.49065180  3.57380175  4.45900946  3.91123613  2.04864728
## [289]  1.69284019 -0.37815901  1.50104762  0.36947578  1.42342958  0.06245159
## [295]  1.99546624  1.08846122  1.36826417
#Yt-1
yt_3_arma <- arma22[-c(298,299,300)]
yt_3_arma
##   [1]  2.26962428  2.41330919  1.73136506 -0.03272495 -1.28436730 -1.27331392
##   [7] -1.76603227 -0.90351688 -1.49889903 -1.41288288  0.38224887 -1.00666389
##  [13] -0.38811892 -2.03542402 -0.09475364  0.25019903  0.21144890 -0.61178019
##  [19] -0.63822978 -0.35475902 -0.24258312  0.83621010  0.95852914  2.72915534
##  [25]  2.37854308  2.70109188  3.18803175  2.41512081  2.13794591  0.30947200
##  [31] -0.03226457  0.27626809  0.13080145 -0.23324048 -1.42754246 -1.83723963
##  [37] -2.09305732 -0.66574366 -1.24710489  0.10982967  0.50408386  0.77993951
##  [43]  3.92863313  3.22885675  3.02952586  1.80587172  0.89707953  1.81515705
##  [49]  3.11098648  2.89081614  3.85609097  1.55611461  0.26026305  0.63341166
##  [55]  0.01252691  2.06466262  1.12791947  1.74915584 -0.26441943  1.41014043
##  [61]  0.52553214  2.47027528  1.65508279  0.85592497  0.16129761  0.12655585
##  [67]  2.11865682  3.54717417  4.38837807  4.32503517  3.91681579  3.75017384
##  [73]  1.83524505  0.04118502 -1.65611843 -0.76047493 -1.18806381 -1.17354412
##  [79] -0.23786915 -2.92601625 -1.30875347 -2.62607044 -1.84193357 -1.60843881
##  [85] -3.06122751 -1.75594837 -2.06753876  0.56382000  1.25962463  2.41656249
##  [91]  2.32738027  2.58492429  0.51487420 -0.46810388 -3.92194379 -1.94918203
##  [97] -2.76868489 -1.91865193 -2.84916202 -2.54784689 -2.36722834 -0.54123071
## [103] -1.49834616 -0.30288454  0.62624978  2.43894962  2.70230943  1.77862592
## [109]  0.11156756 -1.07165154 -2.75043375 -3.14594902 -3.64309452 -1.89885478
## [115] -2.21838910 -2.50028252 -2.09823558 -1.17262803 -1.51992965 -0.77171305
## [121] -1.51966294 -0.76483586 -0.26541577  1.24976251  2.07869890  2.72980057
## [127]  0.62903078  0.63135982 -1.38241073 -1.78189035 -1.51458879 -0.29304176
## [133]  0.81802304  2.66897685  0.80904922  1.23373149  0.70923921  1.42839653
## [139]  2.06731763 -0.07391642 -0.24844192 -0.67703416 -0.48384965 -0.30589271
## [145] -1.81152241 -0.90641039 -1.33785891 -0.62694098  0.61285334  0.57223843
## [151]  1.88791856  1.64061167  2.72718203  2.68427572  4.16816553  3.31279528
## [157]  3.75626565  1.86780798  2.23374909  2.86631153  3.15642102  3.77059892
## [163]  1.94447960  2.41782512 -0.86551177 -1.66336383 -5.31932785 -5.10179286
## [169] -4.72956464 -2.86632422 -1.95098046 -0.90741907  0.85841285  1.79440031
## [175]  3.56614757  3.98837201  3.18572538  2.65733853  2.62676496 -0.78233350
## [181] -0.89297696  0.11587267 -1.52782966  1.76221936 -1.60115625 -0.22194238
## [187] -1.77054568 -0.15825478 -0.01549577 -1.89340635 -2.18579970 -2.84457393
## [193] -2.46655385 -1.56968331 -2.16788282 -0.61817043 -1.32624803 -0.39922827
## [199] -2.04015184 -2.73937914 -2.43096918 -2.14759438 -0.56316855 -1.51974909
## [205]  0.01436185 -0.67484163  2.24129653  2.70051151  4.53094226  3.63881319
## [211]  3.72654583  4.55957651  5.39479909  4.99052004  6.19548365  6.07710298
## [217]  5.04650614  4.03310232  3.26324143  2.52879853  2.06146314  1.74330299
## [223]  1.11531200  1.48320793  1.58208563  1.33478937  3.10865991  0.95916417
## [229]  2.95641872  0.93042836  2.05179921  2.38265402  1.34045610  2.23896973
## [235] -0.23719807  0.29882417 -2.17538094 -0.82399383 -1.83230133 -1.95200811
## [241] -1.68793484 -2.00782024 -2.20038973 -0.97586535 -1.55578841 -0.83495571
## [247] -0.35980322  0.15805693  0.19832638 -0.30115209 -1.48646962 -1.12744745
## [253] -1.26726104 -0.13909013 -0.18802362 -0.43071170 -0.51489995 -1.25303925
## [259] -1.37500332 -0.52418615  0.66912313  2.68451645  2.87771098  2.02827381
## [265]  1.29954794  1.05822657  1.32236657  1.43106538  1.15707700  0.76668759
## [271]  0.98809387 -1.08490119  0.45484899 -1.00423828  1.70169503  1.07265235
## [277]  0.84904993 -0.55717178 -0.28437368 -1.61833190 -0.46212695 -0.85734611
## [283]  1.32334789  1.03077209  1.81284188  1.60898453  2.49065180  3.57380175
## [289]  4.45900946  3.91123613  2.04864728  1.69284019 -0.37815901  1.50104762
## [295]  0.36947578  1.42342958  0.06245159
plot(y=yt3_arma,x=yt_3_arma)

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

cor(yt3_arma,yt_3_arma)
## [1] 0.4929514

Korelasi antara \(Y_t\) dengan \(Y_{t-3}\) dari hasil simulasi sebesar 0.4929514