1. MA(2)

A. Menggunakan Teknik Manual

Bangkitkan data dari set.seed

Bangkitkan data MA(2) dengan \(\theta_1 = 0.4\) dan \(\phi_2 = 0.6\) sebanyak 300 data menggunakan fungsi arima.sim

# Set seed agar hasil replikasi sama
set.seed(123)

White Noise

# Menentukan parameter dan panjang data
n = 300 # Banyak data yang dibangkitkan
theta1 = 0.4 # theta_1 untuk MA(2)
theta2 = 0.6 # theta_2 untuk MA(2)
wn = rnorm(300)
ts.plot(wn)

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

# Asumsi umum 
ma2_man = numeric(n)
ma2_man[1] = wn[1] # Y1 = e1

# Untuk t = 2, Y_2 = e2 + theta_1*e1 + theta_2*e0 (denagn e0 = 0)
ma2_man[2] = wn[2] + theta1 * wn[1]      # Y2 = e2 + theta1*e1
# Pembangkitan model MA (2) manual melalui iterasi
for (t in 3:n) {
  ma2_man[t] <- wn[t] + theta1 * wn[t - 1] + theta2 * wn[t - 2]
}

ma2_man
##   [1] -0.560475647 -0.454367748  1.130351930  0.555885223  1.092716080
##   [6]  1.809085116  1.224514842 -0.051655760 -0.916327622 -1.479439852
##  [11]  0.633705298  0.582049364  1.279146060  0.486879592 -0.271105178
##  [16]  1.630986312  0.879111052 -0.695329083  0.213419326 -1.372219341
##  [21] -0.836126728 -0.928779242 -1.753888638 -1.270077957 -1.532198429
##  [26] -2.374043755 -0.211913841 -0.523528051 -0.574115463  0.890584017
##  [31]  0.245108028  0.627803158  1.032975601  1.059140862  1.709909873
##  [36]  1.544152779  1.322322404  0.572839503  0.001623244 -0.540003093
##  [41] -1.030472978 -0.714082670 -1.765387450  1.538047058  1.316306573
##  [46]  0.661449795 -0.127351070 -1.301674438  0.351572076 -0.051376231
##  [51]  0.687949958  0.022759210  0.097701949  1.334326048  0.295947654
##  [56]  2.247323581 -1.077627154  0.874994991 -0.571551939  0.616251516
##  [61]  0.540328657 -0.220902719 -0.306353075 -1.453252408 -1.679145810
##  [66] -0.736333079 -0.073453501  0.414405323  1.212395026  2.450794209
##  [71]  0.882363189 -1.275530531 -0.212547725 -1.692406678 -0.368245807
##  [76]  0.324847466 -0.287349629 -0.719284093 -0.477847409 -0.798800598
##  [81]  0.058989729  0.304251258 -0.213089360  0.727280776 -0.185131961
##  [86]  0.630213268  1.097259862  1.072986274  0.506244419  1.279543879
##  [91]  1.257467952  1.635083073  1.054192832 -0.203375206  1.252729059
##  [96] -0.432742253  2.763620627  2.047388071  1.689743687 -0.201134668
## [101] -1.262395139 -0.643131457 -0.570182333 -0.292089125 -1.238650734
## [106] -0.634200711 -1.373886700 -2.008920359 -1.518345977 -0.233859161
## [111] -0.435884231  0.929223503 -1.719905157 -0.337936456 -0.473547207
## [116]  0.475579064  0.537781861 -0.417743513 -1.042581033 -1.748434134
## [121] -0.801827527 -1.514893250 -0.798959331 -1.020799938  1.447090662
## [126] -0.068060415  1.080923815 -0.219054463 -0.789440351 -0.409274230
## [131]  0.838913643  0.986539545  1.088565058 -0.135101232 -2.197506201
## [136]  0.056540225 -2.240053518  0.834493811  1.328698531 -0.236283227
## [141]  1.269689213 -0.847819652 -1.255952554 -2.300843811 -3.150689731
## [146] -2.080321584 -2.635039898 -0.215329374  1.498222299 -0.034236836
## [151]  1.532992021  0.311919494  1.112462784 -0.414070232 -0.323481703
## [156] -0.933202343  0.379159835 -0.315480144  1.165791604 -0.207254757
## [161]  1.489063154 -0.852840935 -1.048199168  2.107471633  0.123465239
## [166]  2.076108517  0.505746158 -0.050216201  0.705291598  0.285440970
## [171]  0.242322530  0.200519547 -0.137178345  2.154000818  0.089604311
## [176] -0.115459566 -0.845411765 -0.332001651  0.583388818 -0.097467491
## [181] -0.984758180  0.562835523 -0.482371998 -0.247461912 -0.792274947
## [186] -0.810995440  0.889282191  0.410399871  1.453900876 -0.146828128
## [191]  0.467160774 -0.538482998  0.093376349 -1.052341494 -1.612196760
## [196]  0.935674757  0.613113258  0.187340199 -0.751249167 -2.180709268
## [201]  1.357918765  1.480649065  1.579106343  1.224583822 -0.356149358
## [206] -0.316066438 -1.227705564 -1.195806539  0.939898858  0.249564501
## [211]  1.088178467  0.258968649  1.401497992  0.123138978 -0.459447156
## [216]  0.969055774 -0.366388734  0.105886903 -1.790197437 -2.213064552
## [221] -1.829623640 -0.382433008  1.012658378  1.522319100  0.585286928
## [226]  0.338840031 -0.898890867 -0.963206785  0.175005356 -1.092063276
## [231]  2.079847233  0.082442445  1.351587368 -0.706903930 -0.741076476
## [236] -1.989888231 -1.054365055 -0.444397430  0.382142073 -0.400425306
## [241] -0.906653959 -1.286569399  0.822008000 -0.840198584  0.263663359
## [246]  1.148359012  0.552538887 -0.258813565 -1.269290648 -0.596352217
## [251] -0.580280541 -0.420841525 -0.794029503 -0.384196065  1.428357090
## [256]  0.605136385  2.004478714  1.009934847  0.787141448 -1.199905492
## [261] -1.202462056 -1.618058582 -0.461464139  1.025138179  2.841451105
## [266]  3.244931855  1.861728844 -0.881239146 -1.171281401 -1.120221160
## [271]  0.647427975  1.354057504  1.576328419 -0.544033797  0.702118963
## [276] -0.943864608  0.505965641 -0.123462073  0.562868856  0.240672395
## [281] -1.400705045  0.084310915 -0.319860104  0.330656581  0.243499802
## [286]  0.021905475  0.345521633  1.809677141  0.569899769  1.064952932
## [291]  1.104179799  1.622373803  2.267965844  0.513145857  2.458653396
## [296]  0.521213162  3.095021831 -0.564141426  0.600733619  0.447766394

B. Menggunakan arima.sim

# Membuat data time series dari model MA(2) dengan parameter theta_1 = 0.4 dan theta_2 = 0.6 sebanyak n = 300 observasi 
ma2_data <- arima.sim(list(order = c(0,0,2), ma = c(0.4, 0.6)), n = 300)
ma2_data
## Time Series:
## Start = 1 
## End = 300 
## Frequency = 1 
##   [1] -1.668759603 -1.879542142 -1.421288067 -0.475192608 -2.144034549
##   [6] -0.394996262  0.112940921  2.659432297  2.858210627  2.499789572
##  [11] -0.643314898 -0.838134009 -1.628687379  0.201801295 -0.035489647
##  [16] -0.878802820  1.117573456  0.829976398  1.612648214  1.859915494
##  [21] -0.709072680  0.856175749 -1.061848830  0.871072750 -0.101071172
##  [26]  1.018879244  1.552208727  0.921273564  1.821785242 -0.777036526
##  [31] -0.586442872  0.517515514  0.552112393 -0.989737004 -1.958493796
##  [36] -1.977729689 -0.032955473  0.123959897  1.102901812  1.147550413
##  [41]  2.429169463  1.299841891  0.973057684 -1.740420082 -0.633156493
##  [46] -1.584061436 -1.143153050 -0.912620099  0.358574931 -1.694714958
##  [51] -0.615412779 -1.249923525 -1.102920229  0.046602285  0.009066556
##  [56]  0.331877574 -2.232254705  1.565277173 -0.656254915  2.111948466
##  [61]  0.411064249  1.524895800  1.391788635  0.732074548  0.784846172
##  [66] -0.920017625  0.705660142 -0.685514433  2.746511825 -0.960962558
##  [71]  0.325657211 -0.350844372  0.561892146  0.109799898 -0.926493629
##  [76] -0.607925215 -0.554585577 -1.709318780 -0.690145876 -0.870118000
##  [81]  0.271549164 -0.870988294  0.158962299  0.936013223  1.293344425
##  [86] -0.125951827 -0.616139016 -0.509507651 -0.769991465 -2.208802416
##  [91] -0.367035093 -1.770365085 -0.374800823  0.776789934 -0.516720848
##  [96]  1.438413934 -1.386877221 -0.351376630 -0.971782708 -1.410799274
## [101] -1.146342446 -0.983931714  0.278310389 -1.399573088 -0.607555275
## [106] -0.373823183 -0.446099128  0.465612121  0.259859843  0.601101596
## [111]  1.055728828  0.299295420 -0.070805370 -2.882244754 -1.398406507
## [116] -1.192781082  0.651748108 -0.082947997  1.878630874  0.665058573
## [121]  1.308587372  1.494647775 -0.133769994  0.025634955  1.786237298
## [126]  0.699907005  3.076491584 -0.778401764  0.214221593 -0.560886804
## [131]  0.337098025 -0.658566499 -0.202972102 -1.673098699  0.293290629
## [136]  0.723404028 -1.363455665  0.996563438 -2.081759730  0.699767548
## [141]  0.097183648  0.336932789 -0.329128305 -0.212658458  0.117878735
## [146]  1.158022913 -1.435724635 -1.927332370 -0.455551556  0.636962223
## [151]  1.712181892  1.517271295  1.464419650 -1.864945787  0.596212928
## [156] -1.637430437  0.702788050 -0.493903627  0.892271932 -0.176781148
## [161]  0.902293759 -0.392366942 -0.937958941  0.538484640  0.569231890
## [166]  2.746628550  1.199398835  2.185621662  2.464512512  1.183687154
## [171] -0.250292526 -0.937421281 -1.103552534 -0.077546932  1.644552435
## [176]  0.449786401  1.269930085 -0.274168538  0.153179876  0.185627508
## [181]  1.466108187  0.841038854  1.558298489  1.136787984  1.654022675
## [186]  0.258830774  1.945987356 -0.074840985  0.717961865  1.133162557
## [191]  1.792233513  0.270071851 -0.532617406 -2.361302583 -0.885227031
## [196] -0.577267691  0.539159350  0.796708110 -0.162560948 -0.903161101
## [201]  0.268169912  0.565556170 -0.592670983 -0.248177284 -1.839506725
## [206] -2.486218670 -1.215748991 -1.261614299 -0.038981873  0.129677809
## [211]  0.910504621  0.688275095 -0.004717742 -0.858015086 -0.795584000
## [216] -0.183583682 -0.994755234 -0.414170818  0.269735501  0.168041492
## [221] -0.161372348 -0.620281490  0.585218077  0.830336278  2.125482512
## [226]  0.963794554  1.207919719 -0.310888159  0.628152962 -0.599259422
## [231] -1.259876520 -0.744033362  1.144709101  1.656050606  2.653129856
## [236]  1.305505683  0.234137145 -0.230350293 -0.719278756 -0.699343536
## [241]  0.352738508 -1.196916457  0.809921102  0.492280838 -0.333141685
## [246]  0.678534546  1.966850036  0.798570378  2.080154040 -0.778569438
## [251]  1.304773225  0.224788180  2.418272131 -0.648309740  0.356263057
## [256] -1.422826768 -0.438813671 -1.024639796 -1.204033999 -0.132562303
## [261] -1.356397913  1.396232071 -1.245142641  0.517015076 -0.138303004
## [266]  0.860578545  0.252741044  0.310844533  0.812016952 -1.024259059
## [271] -0.787567587 -0.866173121 -0.785664880  1.384332591  0.954386274
## [276]  1.163470694 -1.074938299 -0.533702650 -1.210630169 -0.213252726
## [281] -1.412347353 -0.035373555 -1.548428759 -0.342609731 -0.332436827
## [286] -0.766678646  0.498440588 -1.553423313 -2.986583996 -1.448848122
## [291] -0.659337784  0.329351302  0.894111981 -1.125773277 -0.287039464
## [296] -2.685927734  0.328284377  1.167472192  2.526685140  1.518204455

Plot Time Series

Melihat pola data

# Membuat time series plot
ts.plot(ma2_data, main = "Plot Time Series MA(2)", ylab = "Yt")

Fluktuasi acak, cenderung tidak terlihat adanya tren sesuai dengan karakter MA

Plot ACF (Autocorrelation Function)

Mengidentifikasi keteganntungan antarlag

# Membuat plot fungsi ACF 
acf(ma2_data, main = "Autocorrelation Function (ACF)")

Ada lag yang cut off di lag ke-2

Plot PACF (Partial Autocorrelation Function)

Menentukan orde AR

# Membuat plot fungsi PACF
pacf(ma2_data, main = "Partial Autocorrelation Function (PACF)")

Plot PACF untuk model MA(2) ini menunjukkan adanya tails off

Plot EACF (Extended Autocorrelation Function)

Mengidentifikasi model MA(q) vs AR(p)

# Mengitung EACF
library(TSA)
## 
## Attaching package: 'TSA'
## The following objects are masked from 'package:stats':
## 
##     acf, arima
## The following object is masked from 'package:utils':
## 
##     tar
eacf(ma2_data)
## 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 x x o o o o o o o  o  o  o 
## 3 x x x o o o o o o o o  o  o  o 
## 4 x x x o o x o o o o o  o  o  o 
## 5 x x o o o x x o o o o  o  o  o 
## 6 x x o o x x x x o o o  o  o  o 
## 7 x x o x x x x x x 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)

Scatter Plot

# Yt
yt_ma2 = ma2_data[-c(1:3)] # Buang 3 data awal agar sejajar dengan Yt-1, Yt-2, Yt-3

# Yt-1
yt_1_ma2 = ma2_data[-c(300, 1:2)]  # buang 2 data awal + 1 data akhir

# Yt-2
yt_2_ma2 = ma2_data[-c((199):300, 1)]  # buang 1 data awal + 2 data akhir

# Yt-3
yt_3_ma2 = ma2_data[-c((298):300)]  # buang 3 data akhir
# Perbandingan Yt dengan Yt-1
yt_ma2
##   [1] -0.475192608 -2.144034549 -0.394996262  0.112940921  2.659432297
##   [6]  2.858210627  2.499789572 -0.643314898 -0.838134009 -1.628687379
##  [11]  0.201801295 -0.035489647 -0.878802820  1.117573456  0.829976398
##  [16]  1.612648214  1.859915494 -0.709072680  0.856175749 -1.061848830
##  [21]  0.871072750 -0.101071172  1.018879244  1.552208727  0.921273564
##  [26]  1.821785242 -0.777036526 -0.586442872  0.517515514  0.552112393
##  [31] -0.989737004 -1.958493796 -1.977729689 -0.032955473  0.123959897
##  [36]  1.102901812  1.147550413  2.429169463  1.299841891  0.973057684
##  [41] -1.740420082 -0.633156493 -1.584061436 -1.143153050 -0.912620099
##  [46]  0.358574931 -1.694714958 -0.615412779 -1.249923525 -1.102920229
##  [51]  0.046602285  0.009066556  0.331877574 -2.232254705  1.565277173
##  [56] -0.656254915  2.111948466  0.411064249  1.524895800  1.391788635
##  [61]  0.732074548  0.784846172 -0.920017625  0.705660142 -0.685514433
##  [66]  2.746511825 -0.960962558  0.325657211 -0.350844372  0.561892146
##  [71]  0.109799898 -0.926493629 -0.607925215 -0.554585577 -1.709318780
##  [76] -0.690145876 -0.870118000  0.271549164 -0.870988294  0.158962299
##  [81]  0.936013223  1.293344425 -0.125951827 -0.616139016 -0.509507651
##  [86] -0.769991465 -2.208802416 -0.367035093 -1.770365085 -0.374800823
##  [91]  0.776789934 -0.516720848  1.438413934 -1.386877221 -0.351376630
##  [96] -0.971782708 -1.410799274 -1.146342446 -0.983931714  0.278310389
## [101] -1.399573088 -0.607555275 -0.373823183 -0.446099128  0.465612121
## [106]  0.259859843  0.601101596  1.055728828  0.299295420 -0.070805370
## [111] -2.882244754 -1.398406507 -1.192781082  0.651748108 -0.082947997
## [116]  1.878630874  0.665058573  1.308587372  1.494647775 -0.133769994
## [121]  0.025634955  1.786237298  0.699907005  3.076491584 -0.778401764
## [126]  0.214221593 -0.560886804  0.337098025 -0.658566499 -0.202972102
## [131] -1.673098699  0.293290629  0.723404028 -1.363455665  0.996563438
## [136] -2.081759730  0.699767548  0.097183648  0.336932789 -0.329128305
## [141] -0.212658458  0.117878735  1.158022913 -1.435724635 -1.927332370
## [146] -0.455551556  0.636962223  1.712181892  1.517271295  1.464419650
## [151] -1.864945787  0.596212928 -1.637430437  0.702788050 -0.493903627
## [156]  0.892271932 -0.176781148  0.902293759 -0.392366942 -0.937958941
## [161]  0.538484640  0.569231890  2.746628550  1.199398835  2.185621662
## [166]  2.464512512  1.183687154 -0.250292526 -0.937421281 -1.103552534
## [171] -0.077546932  1.644552435  0.449786401  1.269930085 -0.274168538
## [176]  0.153179876  0.185627508  1.466108187  0.841038854  1.558298489
## [181]  1.136787984  1.654022675  0.258830774  1.945987356 -0.074840985
## [186]  0.717961865  1.133162557  1.792233513  0.270071851 -0.532617406
## [191] -2.361302583 -0.885227031 -0.577267691  0.539159350  0.796708110
## [196] -0.162560948 -0.903161101  0.268169912  0.565556170 -0.592670983
## [201] -0.248177284 -1.839506725 -2.486218670 -1.215748991 -1.261614299
## [206] -0.038981873  0.129677809  0.910504621  0.688275095 -0.004717742
## [211] -0.858015086 -0.795584000 -0.183583682 -0.994755234 -0.414170818
## [216]  0.269735501  0.168041492 -0.161372348 -0.620281490  0.585218077
## [221]  0.830336278  2.125482512  0.963794554  1.207919719 -0.310888159
## [226]  0.628152962 -0.599259422 -1.259876520 -0.744033362  1.144709101
## [231]  1.656050606  2.653129856  1.305505683  0.234137145 -0.230350293
## [236] -0.719278756 -0.699343536  0.352738508 -1.196916457  0.809921102
## [241]  0.492280838 -0.333141685  0.678534546  1.966850036  0.798570378
## [246]  2.080154040 -0.778569438  1.304773225  0.224788180  2.418272131
## [251] -0.648309740  0.356263057 -1.422826768 -0.438813671 -1.024639796
## [256] -1.204033999 -0.132562303 -1.356397913  1.396232071 -1.245142641
## [261]  0.517015076 -0.138303004  0.860578545  0.252741044  0.310844533
## [266]  0.812016952 -1.024259059 -0.787567587 -0.866173121 -0.785664880
## [271]  1.384332591  0.954386274  1.163470694 -1.074938299 -0.533702650
## [276] -1.210630169 -0.213252726 -1.412347353 -0.035373555 -1.548428759
## [281] -0.342609731 -0.332436827 -0.766678646  0.498440588 -1.553423313
## [286] -2.986583996 -1.448848122 -0.659337784  0.329351302  0.894111981
## [291] -1.125773277 -0.287039464 -2.685927734  0.328284377  1.167472192
## [296]  2.526685140  1.518204455
yt_1_ma2
##   [1] -1.421288067 -0.475192608 -2.144034549 -0.394996262  0.112940921
##   [6]  2.659432297  2.858210627  2.499789572 -0.643314898 -0.838134009
##  [11] -1.628687379  0.201801295 -0.035489647 -0.878802820  1.117573456
##  [16]  0.829976398  1.612648214  1.859915494 -0.709072680  0.856175749
##  [21] -1.061848830  0.871072750 -0.101071172  1.018879244  1.552208727
##  [26]  0.921273564  1.821785242 -0.777036526 -0.586442872  0.517515514
##  [31]  0.552112393 -0.989737004 -1.958493796 -1.977729689 -0.032955473
##  [36]  0.123959897  1.102901812  1.147550413  2.429169463  1.299841891
##  [41]  0.973057684 -1.740420082 -0.633156493 -1.584061436 -1.143153050
##  [46] -0.912620099  0.358574931 -1.694714958 -0.615412779 -1.249923525
##  [51] -1.102920229  0.046602285  0.009066556  0.331877574 -2.232254705
##  [56]  1.565277173 -0.656254915  2.111948466  0.411064249  1.524895800
##  [61]  1.391788635  0.732074548  0.784846172 -0.920017625  0.705660142
##  [66] -0.685514433  2.746511825 -0.960962558  0.325657211 -0.350844372
##  [71]  0.561892146  0.109799898 -0.926493629 -0.607925215 -0.554585577
##  [76] -1.709318780 -0.690145876 -0.870118000  0.271549164 -0.870988294
##  [81]  0.158962299  0.936013223  1.293344425 -0.125951827 -0.616139016
##  [86] -0.509507651 -0.769991465 -2.208802416 -0.367035093 -1.770365085
##  [91] -0.374800823  0.776789934 -0.516720848  1.438413934 -1.386877221
##  [96] -0.351376630 -0.971782708 -1.410799274 -1.146342446 -0.983931714
## [101]  0.278310389 -1.399573088 -0.607555275 -0.373823183 -0.446099128
## [106]  0.465612121  0.259859843  0.601101596  1.055728828  0.299295420
## [111] -0.070805370 -2.882244754 -1.398406507 -1.192781082  0.651748108
## [116] -0.082947997  1.878630874  0.665058573  1.308587372  1.494647775
## [121] -0.133769994  0.025634955  1.786237298  0.699907005  3.076491584
## [126] -0.778401764  0.214221593 -0.560886804  0.337098025 -0.658566499
## [131] -0.202972102 -1.673098699  0.293290629  0.723404028 -1.363455665
## [136]  0.996563438 -2.081759730  0.699767548  0.097183648  0.336932789
## [141] -0.329128305 -0.212658458  0.117878735  1.158022913 -1.435724635
## [146] -1.927332370 -0.455551556  0.636962223  1.712181892  1.517271295
## [151]  1.464419650 -1.864945787  0.596212928 -1.637430437  0.702788050
## [156] -0.493903627  0.892271932 -0.176781148  0.902293759 -0.392366942
## [161] -0.937958941  0.538484640  0.569231890  2.746628550  1.199398835
## [166]  2.185621662  2.464512512  1.183687154 -0.250292526 -0.937421281
## [171] -1.103552534 -0.077546932  1.644552435  0.449786401  1.269930085
## [176] -0.274168538  0.153179876  0.185627508  1.466108187  0.841038854
## [181]  1.558298489  1.136787984  1.654022675  0.258830774  1.945987356
## [186] -0.074840985  0.717961865  1.133162557  1.792233513  0.270071851
## [191] -0.532617406 -2.361302583 -0.885227031 -0.577267691  0.539159350
## [196]  0.796708110 -0.162560948 -0.903161101  0.268169912  0.565556170
## [201] -0.592670983 -0.248177284 -1.839506725 -2.486218670 -1.215748991
## [206] -1.261614299 -0.038981873  0.129677809  0.910504621  0.688275095
## [211] -0.004717742 -0.858015086 -0.795584000 -0.183583682 -0.994755234
## [216] -0.414170818  0.269735501  0.168041492 -0.161372348 -0.620281490
## [221]  0.585218077  0.830336278  2.125482512  0.963794554  1.207919719
## [226] -0.310888159  0.628152962 -0.599259422 -1.259876520 -0.744033362
## [231]  1.144709101  1.656050606  2.653129856  1.305505683  0.234137145
## [236] -0.230350293 -0.719278756 -0.699343536  0.352738508 -1.196916457
## [241]  0.809921102  0.492280838 -0.333141685  0.678534546  1.966850036
## [246]  0.798570378  2.080154040 -0.778569438  1.304773225  0.224788180
## [251]  2.418272131 -0.648309740  0.356263057 -1.422826768 -0.438813671
## [256] -1.024639796 -1.204033999 -0.132562303 -1.356397913  1.396232071
## [261] -1.245142641  0.517015076 -0.138303004  0.860578545  0.252741044
## [266]  0.310844533  0.812016952 -1.024259059 -0.787567587 -0.866173121
## [271] -0.785664880  1.384332591  0.954386274  1.163470694 -1.074938299
## [276] -0.533702650 -1.210630169 -0.213252726 -1.412347353 -0.035373555
## [281] -1.548428759 -0.342609731 -0.332436827 -0.766678646  0.498440588
## [286] -1.553423313 -2.986583996 -1.448848122 -0.659337784  0.329351302
## [291]  0.894111981 -1.125773277 -0.287039464 -2.685927734  0.328284377
## [296]  1.167472192  2.526685140
# Perbandingan Yt dengan Yt-2 
yt_ma2
##   [1] -0.475192608 -2.144034549 -0.394996262  0.112940921  2.659432297
##   [6]  2.858210627  2.499789572 -0.643314898 -0.838134009 -1.628687379
##  [11]  0.201801295 -0.035489647 -0.878802820  1.117573456  0.829976398
##  [16]  1.612648214  1.859915494 -0.709072680  0.856175749 -1.061848830
##  [21]  0.871072750 -0.101071172  1.018879244  1.552208727  0.921273564
##  [26]  1.821785242 -0.777036526 -0.586442872  0.517515514  0.552112393
##  [31] -0.989737004 -1.958493796 -1.977729689 -0.032955473  0.123959897
##  [36]  1.102901812  1.147550413  2.429169463  1.299841891  0.973057684
##  [41] -1.740420082 -0.633156493 -1.584061436 -1.143153050 -0.912620099
##  [46]  0.358574931 -1.694714958 -0.615412779 -1.249923525 -1.102920229
##  [51]  0.046602285  0.009066556  0.331877574 -2.232254705  1.565277173
##  [56] -0.656254915  2.111948466  0.411064249  1.524895800  1.391788635
##  [61]  0.732074548  0.784846172 -0.920017625  0.705660142 -0.685514433
##  [66]  2.746511825 -0.960962558  0.325657211 -0.350844372  0.561892146
##  [71]  0.109799898 -0.926493629 -0.607925215 -0.554585577 -1.709318780
##  [76] -0.690145876 -0.870118000  0.271549164 -0.870988294  0.158962299
##  [81]  0.936013223  1.293344425 -0.125951827 -0.616139016 -0.509507651
##  [86] -0.769991465 -2.208802416 -0.367035093 -1.770365085 -0.374800823
##  [91]  0.776789934 -0.516720848  1.438413934 -1.386877221 -0.351376630
##  [96] -0.971782708 -1.410799274 -1.146342446 -0.983931714  0.278310389
## [101] -1.399573088 -0.607555275 -0.373823183 -0.446099128  0.465612121
## [106]  0.259859843  0.601101596  1.055728828  0.299295420 -0.070805370
## [111] -2.882244754 -1.398406507 -1.192781082  0.651748108 -0.082947997
## [116]  1.878630874  0.665058573  1.308587372  1.494647775 -0.133769994
## [121]  0.025634955  1.786237298  0.699907005  3.076491584 -0.778401764
## [126]  0.214221593 -0.560886804  0.337098025 -0.658566499 -0.202972102
## [131] -1.673098699  0.293290629  0.723404028 -1.363455665  0.996563438
## [136] -2.081759730  0.699767548  0.097183648  0.336932789 -0.329128305
## [141] -0.212658458  0.117878735  1.158022913 -1.435724635 -1.927332370
## [146] -0.455551556  0.636962223  1.712181892  1.517271295  1.464419650
## [151] -1.864945787  0.596212928 -1.637430437  0.702788050 -0.493903627
## [156]  0.892271932 -0.176781148  0.902293759 -0.392366942 -0.937958941
## [161]  0.538484640  0.569231890  2.746628550  1.199398835  2.185621662
## [166]  2.464512512  1.183687154 -0.250292526 -0.937421281 -1.103552534
## [171] -0.077546932  1.644552435  0.449786401  1.269930085 -0.274168538
## [176]  0.153179876  0.185627508  1.466108187  0.841038854  1.558298489
## [181]  1.136787984  1.654022675  0.258830774  1.945987356 -0.074840985
## [186]  0.717961865  1.133162557  1.792233513  0.270071851 -0.532617406
## [191] -2.361302583 -0.885227031 -0.577267691  0.539159350  0.796708110
## [196] -0.162560948 -0.903161101  0.268169912  0.565556170 -0.592670983
## [201] -0.248177284 -1.839506725 -2.486218670 -1.215748991 -1.261614299
## [206] -0.038981873  0.129677809  0.910504621  0.688275095 -0.004717742
## [211] -0.858015086 -0.795584000 -0.183583682 -0.994755234 -0.414170818
## [216]  0.269735501  0.168041492 -0.161372348 -0.620281490  0.585218077
## [221]  0.830336278  2.125482512  0.963794554  1.207919719 -0.310888159
## [226]  0.628152962 -0.599259422 -1.259876520 -0.744033362  1.144709101
## [231]  1.656050606  2.653129856  1.305505683  0.234137145 -0.230350293
## [236] -0.719278756 -0.699343536  0.352738508 -1.196916457  0.809921102
## [241]  0.492280838 -0.333141685  0.678534546  1.966850036  0.798570378
## [246]  2.080154040 -0.778569438  1.304773225  0.224788180  2.418272131
## [251] -0.648309740  0.356263057 -1.422826768 -0.438813671 -1.024639796
## [256] -1.204033999 -0.132562303 -1.356397913  1.396232071 -1.245142641
## [261]  0.517015076 -0.138303004  0.860578545  0.252741044  0.310844533
## [266]  0.812016952 -1.024259059 -0.787567587 -0.866173121 -0.785664880
## [271]  1.384332591  0.954386274  1.163470694 -1.074938299 -0.533702650
## [276] -1.210630169 -0.213252726 -1.412347353 -0.035373555 -1.548428759
## [281] -0.342609731 -0.332436827 -0.766678646  0.498440588 -1.553423313
## [286] -2.986583996 -1.448848122 -0.659337784  0.329351302  0.894111981
## [291] -1.125773277 -0.287039464 -2.685927734  0.328284377  1.167472192
## [296]  2.526685140  1.518204455
yt_2_ma2
##   [1] -1.879542142 -1.421288067 -0.475192608 -2.144034549 -0.394996262
##   [6]  0.112940921  2.659432297  2.858210627  2.499789572 -0.643314898
##  [11] -0.838134009 -1.628687379  0.201801295 -0.035489647 -0.878802820
##  [16]  1.117573456  0.829976398  1.612648214  1.859915494 -0.709072680
##  [21]  0.856175749 -1.061848830  0.871072750 -0.101071172  1.018879244
##  [26]  1.552208727  0.921273564  1.821785242 -0.777036526 -0.586442872
##  [31]  0.517515514  0.552112393 -0.989737004 -1.958493796 -1.977729689
##  [36] -0.032955473  0.123959897  1.102901812  1.147550413  2.429169463
##  [41]  1.299841891  0.973057684 -1.740420082 -0.633156493 -1.584061436
##  [46] -1.143153050 -0.912620099  0.358574931 -1.694714958 -0.615412779
##  [51] -1.249923525 -1.102920229  0.046602285  0.009066556  0.331877574
##  [56] -2.232254705  1.565277173 -0.656254915  2.111948466  0.411064249
##  [61]  1.524895800  1.391788635  0.732074548  0.784846172 -0.920017625
##  [66]  0.705660142 -0.685514433  2.746511825 -0.960962558  0.325657211
##  [71] -0.350844372  0.561892146  0.109799898 -0.926493629 -0.607925215
##  [76] -0.554585577 -1.709318780 -0.690145876 -0.870118000  0.271549164
##  [81] -0.870988294  0.158962299  0.936013223  1.293344425 -0.125951827
##  [86] -0.616139016 -0.509507651 -0.769991465 -2.208802416 -0.367035093
##  [91] -1.770365085 -0.374800823  0.776789934 -0.516720848  1.438413934
##  [96] -1.386877221 -0.351376630 -0.971782708 -1.410799274 -1.146342446
## [101] -0.983931714  0.278310389 -1.399573088 -0.607555275 -0.373823183
## [106] -0.446099128  0.465612121  0.259859843  0.601101596  1.055728828
## [111]  0.299295420 -0.070805370 -2.882244754 -1.398406507 -1.192781082
## [116]  0.651748108 -0.082947997  1.878630874  0.665058573  1.308587372
## [121]  1.494647775 -0.133769994  0.025634955  1.786237298  0.699907005
## [126]  3.076491584 -0.778401764  0.214221593 -0.560886804  0.337098025
## [131] -0.658566499 -0.202972102 -1.673098699  0.293290629  0.723404028
## [136] -1.363455665  0.996563438 -2.081759730  0.699767548  0.097183648
## [141]  0.336932789 -0.329128305 -0.212658458  0.117878735  1.158022913
## [146] -1.435724635 -1.927332370 -0.455551556  0.636962223  1.712181892
## [151]  1.517271295  1.464419650 -1.864945787  0.596212928 -1.637430437
## [156]  0.702788050 -0.493903627  0.892271932 -0.176781148  0.902293759
## [161] -0.392366942 -0.937958941  0.538484640  0.569231890  2.746628550
## [166]  1.199398835  2.185621662  2.464512512  1.183687154 -0.250292526
## [171] -0.937421281 -1.103552534 -0.077546932  1.644552435  0.449786401
## [176]  1.269930085 -0.274168538  0.153179876  0.185627508  1.466108187
## [181]  0.841038854  1.558298489  1.136787984  1.654022675  0.258830774
## [186]  1.945987356 -0.074840985  0.717961865  1.133162557  1.792233513
## [191]  0.270071851 -0.532617406 -2.361302583 -0.885227031 -0.577267691
## [196]  0.539159350  0.796708110
# Perbandingan Yt dengan Yt-3
yt_ma2
##   [1] -0.475192608 -2.144034549 -0.394996262  0.112940921  2.659432297
##   [6]  2.858210627  2.499789572 -0.643314898 -0.838134009 -1.628687379
##  [11]  0.201801295 -0.035489647 -0.878802820  1.117573456  0.829976398
##  [16]  1.612648214  1.859915494 -0.709072680  0.856175749 -1.061848830
##  [21]  0.871072750 -0.101071172  1.018879244  1.552208727  0.921273564
##  [26]  1.821785242 -0.777036526 -0.586442872  0.517515514  0.552112393
##  [31] -0.989737004 -1.958493796 -1.977729689 -0.032955473  0.123959897
##  [36]  1.102901812  1.147550413  2.429169463  1.299841891  0.973057684
##  [41] -1.740420082 -0.633156493 -1.584061436 -1.143153050 -0.912620099
##  [46]  0.358574931 -1.694714958 -0.615412779 -1.249923525 -1.102920229
##  [51]  0.046602285  0.009066556  0.331877574 -2.232254705  1.565277173
##  [56] -0.656254915  2.111948466  0.411064249  1.524895800  1.391788635
##  [61]  0.732074548  0.784846172 -0.920017625  0.705660142 -0.685514433
##  [66]  2.746511825 -0.960962558  0.325657211 -0.350844372  0.561892146
##  [71]  0.109799898 -0.926493629 -0.607925215 -0.554585577 -1.709318780
##  [76] -0.690145876 -0.870118000  0.271549164 -0.870988294  0.158962299
##  [81]  0.936013223  1.293344425 -0.125951827 -0.616139016 -0.509507651
##  [86] -0.769991465 -2.208802416 -0.367035093 -1.770365085 -0.374800823
##  [91]  0.776789934 -0.516720848  1.438413934 -1.386877221 -0.351376630
##  [96] -0.971782708 -1.410799274 -1.146342446 -0.983931714  0.278310389
## [101] -1.399573088 -0.607555275 -0.373823183 -0.446099128  0.465612121
## [106]  0.259859843  0.601101596  1.055728828  0.299295420 -0.070805370
## [111] -2.882244754 -1.398406507 -1.192781082  0.651748108 -0.082947997
## [116]  1.878630874  0.665058573  1.308587372  1.494647775 -0.133769994
## [121]  0.025634955  1.786237298  0.699907005  3.076491584 -0.778401764
## [126]  0.214221593 -0.560886804  0.337098025 -0.658566499 -0.202972102
## [131] -1.673098699  0.293290629  0.723404028 -1.363455665  0.996563438
## [136] -2.081759730  0.699767548  0.097183648  0.336932789 -0.329128305
## [141] -0.212658458  0.117878735  1.158022913 -1.435724635 -1.927332370
## [146] -0.455551556  0.636962223  1.712181892  1.517271295  1.464419650
## [151] -1.864945787  0.596212928 -1.637430437  0.702788050 -0.493903627
## [156]  0.892271932 -0.176781148  0.902293759 -0.392366942 -0.937958941
## [161]  0.538484640  0.569231890  2.746628550  1.199398835  2.185621662
## [166]  2.464512512  1.183687154 -0.250292526 -0.937421281 -1.103552534
## [171] -0.077546932  1.644552435  0.449786401  1.269930085 -0.274168538
## [176]  0.153179876  0.185627508  1.466108187  0.841038854  1.558298489
## [181]  1.136787984  1.654022675  0.258830774  1.945987356 -0.074840985
## [186]  0.717961865  1.133162557  1.792233513  0.270071851 -0.532617406
## [191] -2.361302583 -0.885227031 -0.577267691  0.539159350  0.796708110
## [196] -0.162560948 -0.903161101  0.268169912  0.565556170 -0.592670983
## [201] -0.248177284 -1.839506725 -2.486218670 -1.215748991 -1.261614299
## [206] -0.038981873  0.129677809  0.910504621  0.688275095 -0.004717742
## [211] -0.858015086 -0.795584000 -0.183583682 -0.994755234 -0.414170818
## [216]  0.269735501  0.168041492 -0.161372348 -0.620281490  0.585218077
## [221]  0.830336278  2.125482512  0.963794554  1.207919719 -0.310888159
## [226]  0.628152962 -0.599259422 -1.259876520 -0.744033362  1.144709101
## [231]  1.656050606  2.653129856  1.305505683  0.234137145 -0.230350293
## [236] -0.719278756 -0.699343536  0.352738508 -1.196916457  0.809921102
## [241]  0.492280838 -0.333141685  0.678534546  1.966850036  0.798570378
## [246]  2.080154040 -0.778569438  1.304773225  0.224788180  2.418272131
## [251] -0.648309740  0.356263057 -1.422826768 -0.438813671 -1.024639796
## [256] -1.204033999 -0.132562303 -1.356397913  1.396232071 -1.245142641
## [261]  0.517015076 -0.138303004  0.860578545  0.252741044  0.310844533
## [266]  0.812016952 -1.024259059 -0.787567587 -0.866173121 -0.785664880
## [271]  1.384332591  0.954386274  1.163470694 -1.074938299 -0.533702650
## [276] -1.210630169 -0.213252726 -1.412347353 -0.035373555 -1.548428759
## [281] -0.342609731 -0.332436827 -0.766678646  0.498440588 -1.553423313
## [286] -2.986583996 -1.448848122 -0.659337784  0.329351302  0.894111981
## [291] -1.125773277 -0.287039464 -2.685927734  0.328284377  1.167472192
## [296]  2.526685140  1.518204455
yt_3_ma2
##   [1] -1.668759603 -1.879542142 -1.421288067 -0.475192608 -2.144034549
##   [6] -0.394996262  0.112940921  2.659432297  2.858210627  2.499789572
##  [11] -0.643314898 -0.838134009 -1.628687379  0.201801295 -0.035489647
##  [16] -0.878802820  1.117573456  0.829976398  1.612648214  1.859915494
##  [21] -0.709072680  0.856175749 -1.061848830  0.871072750 -0.101071172
##  [26]  1.018879244  1.552208727  0.921273564  1.821785242 -0.777036526
##  [31] -0.586442872  0.517515514  0.552112393 -0.989737004 -1.958493796
##  [36] -1.977729689 -0.032955473  0.123959897  1.102901812  1.147550413
##  [41]  2.429169463  1.299841891  0.973057684 -1.740420082 -0.633156493
##  [46] -1.584061436 -1.143153050 -0.912620099  0.358574931 -1.694714958
##  [51] -0.615412779 -1.249923525 -1.102920229  0.046602285  0.009066556
##  [56]  0.331877574 -2.232254705  1.565277173 -0.656254915  2.111948466
##  [61]  0.411064249  1.524895800  1.391788635  0.732074548  0.784846172
##  [66] -0.920017625  0.705660142 -0.685514433  2.746511825 -0.960962558
##  [71]  0.325657211 -0.350844372  0.561892146  0.109799898 -0.926493629
##  [76] -0.607925215 -0.554585577 -1.709318780 -0.690145876 -0.870118000
##  [81]  0.271549164 -0.870988294  0.158962299  0.936013223  1.293344425
##  [86] -0.125951827 -0.616139016 -0.509507651 -0.769991465 -2.208802416
##  [91] -0.367035093 -1.770365085 -0.374800823  0.776789934 -0.516720848
##  [96]  1.438413934 -1.386877221 -0.351376630 -0.971782708 -1.410799274
## [101] -1.146342446 -0.983931714  0.278310389 -1.399573088 -0.607555275
## [106] -0.373823183 -0.446099128  0.465612121  0.259859843  0.601101596
## [111]  1.055728828  0.299295420 -0.070805370 -2.882244754 -1.398406507
## [116] -1.192781082  0.651748108 -0.082947997  1.878630874  0.665058573
## [121]  1.308587372  1.494647775 -0.133769994  0.025634955  1.786237298
## [126]  0.699907005  3.076491584 -0.778401764  0.214221593 -0.560886804
## [131]  0.337098025 -0.658566499 -0.202972102 -1.673098699  0.293290629
## [136]  0.723404028 -1.363455665  0.996563438 -2.081759730  0.699767548
## [141]  0.097183648  0.336932789 -0.329128305 -0.212658458  0.117878735
## [146]  1.158022913 -1.435724635 -1.927332370 -0.455551556  0.636962223
## [151]  1.712181892  1.517271295  1.464419650 -1.864945787  0.596212928
## [156] -1.637430437  0.702788050 -0.493903627  0.892271932 -0.176781148
## [161]  0.902293759 -0.392366942 -0.937958941  0.538484640  0.569231890
## [166]  2.746628550  1.199398835  2.185621662  2.464512512  1.183687154
## [171] -0.250292526 -0.937421281 -1.103552534 -0.077546932  1.644552435
## [176]  0.449786401  1.269930085 -0.274168538  0.153179876  0.185627508
## [181]  1.466108187  0.841038854  1.558298489  1.136787984  1.654022675
## [186]  0.258830774  1.945987356 -0.074840985  0.717961865  1.133162557
## [191]  1.792233513  0.270071851 -0.532617406 -2.361302583 -0.885227031
## [196] -0.577267691  0.539159350  0.796708110 -0.162560948 -0.903161101
## [201]  0.268169912  0.565556170 -0.592670983 -0.248177284 -1.839506725
## [206] -2.486218670 -1.215748991 -1.261614299 -0.038981873  0.129677809
## [211]  0.910504621  0.688275095 -0.004717742 -0.858015086 -0.795584000
## [216] -0.183583682 -0.994755234 -0.414170818  0.269735501  0.168041492
## [221] -0.161372348 -0.620281490  0.585218077  0.830336278  2.125482512
## [226]  0.963794554  1.207919719 -0.310888159  0.628152962 -0.599259422
## [231] -1.259876520 -0.744033362  1.144709101  1.656050606  2.653129856
## [236]  1.305505683  0.234137145 -0.230350293 -0.719278756 -0.699343536
## [241]  0.352738508 -1.196916457  0.809921102  0.492280838 -0.333141685
## [246]  0.678534546  1.966850036  0.798570378  2.080154040 -0.778569438
## [251]  1.304773225  0.224788180  2.418272131 -0.648309740  0.356263057
## [256] -1.422826768 -0.438813671 -1.024639796 -1.204033999 -0.132562303
## [261] -1.356397913  1.396232071 -1.245142641  0.517015076 -0.138303004
## [266]  0.860578545  0.252741044  0.310844533  0.812016952 -1.024259059
## [271] -0.787567587 -0.866173121 -0.785664880  1.384332591  0.954386274
## [276]  1.163470694 -1.074938299 -0.533702650 -1.210630169 -0.213252726
## [281] -1.412347353 -0.035373555 -1.548428759 -0.342609731 -0.332436827
## [286] -0.766678646  0.498440588 -1.553423313 -2.986583996 -1.448848122
## [291] -0.659337784  0.329351302  0.894111981 -1.125773277 -0.287039464
## [296] -2.685927734  0.328284377
# Scatterplot Yt vs Yt-1
plot(ma2_data[-300], ma2_data[-1], main = "Scatterplot Yt vs Yt-1", xlab = "Yt-1", ylab = "Yt")

# Scatterplot Yt vs Yt-2
plot(ma2_data[-c(299:300)], ma2_data[-c(1:2)], main = "Scatterplot Yt vs Yt-2", xlab = "Yt-2", ylab = "Yt")

# Scatterplot Yt vs Yt-3
plot(ma2_data[-c(298:300)], ma2_data[-c(1:3)], main = "Scatterplot Yt vs Yt-3", xlab = "Yt-3", ylab = "Yt")

Hitung Autokorelasi dari hasil simulasi

acf_values <- acf(ma2_data, plot = FALSE)
acf_values$acf[1:5] # Menampilkan dari lag 1 sampai lag 5 
## [1]  0.31992344  0.34346072 -0.11124814 -0.05630001 -0.08545317

Hitung Autokorelasi teoritis untuk MA(2)

Rumus: \(\rho_k\) = \(\gamma_k\) / \(\gamma_0\), dengan

\(\gamma_0\) = (1 + \(\theta_1^2\)+ \(\theta_2^2\)) * \(\sigma^2\)

\(\gamma_1\) = ( \(\theta_1\) + \(\theta_1\theta_2\)) \(\sigma^2\)

\(\gamma_2\) = \(\theta_{2}\) * \(\sigma^2\)

\(\gamma_k\) = 0 untuk k > 2

# Hitung theta
theta1 = 0.4
theta2 = 0.6
sigma2 = 1
# Hitung gamma 
gamma0 = (1 + theta1^2 + theta2^2) * sigma2 # Varians dari proses 
gamma1 = (theta1 + theta1*theta2) * sigma2 # Kovarians lag 1
gamma2 = theta2 * sigma2 # Kovarians lag 2
# Hitung rho
rho1 = gamma1 / gamma0
rho2 = gamma2 / gamma0
rho3 = 0
# Tampilkan hasil autokorelasi teoritis untuk MA(2)
c(rho1, rho2, rho3)
## [1] 0.4210526 0.3947368 0.0000000

Hasil ACF, PACF, dan EACF menunnjukkan bahwa hasil simulai model MA(2) itu stationer karena

  • ACF cut off setelah lag 2

  • PACF tails off

  • EACF menunjukkan pola sesuai dengan MA(2) yaitu segitiga nol berada pada ordo AR(0)

2. AR(2)

A. Menggunakan Teknik Manual

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

Bangkitkan data dari set.seed

Bangkitkan data AR(2) dengan \(\phi_1 = 0.4\) dan \(\phi_2 = 0.6\) sebanyak 300 data menggunakan fungsi arima.sim

set.seed(1234)

White Noise

set.seed(1234)
n = 300
wn = rnorm(n)   # white noise
y_ar2 = numeric(n)  # kosongkan vektor

# Bangkitkan AR(2): Yt = 0.5*Yt-1 + 0.2*Yt-2 + wn[t]
y_ar2 [1:2] = wn[1:2]  # nilai awal
for (t in 3:n) {
  y_ar2[t] <- 0.5*y_ar2[t-1] + 0.2*y_ar2[t-2] + wn[t]
}
y_ar2
##   [1] -1.207065749  0.277429242  0.981742648 -1.799340530 -0.274197047
##   [6]  0.009089263 -0.625034738 -0.857331372 -1.118124633 -1.620566420
##  [11] -1.511100836 -2.078050147 -2.117499135 -1.409900780 -0.168956158
##  [16] -0.476743729 -0.783172602 -1.398130464 -1.692871432  1.289773370
##  [21]  0.440400618 -0.012530914 -0.358733205  0.277716656 -0.626608560
##  [26] -1.705965859 -0.403548921 -1.566623355 -0.879159762 -1.688853153
##  [31]  0.082039017 -0.772344201 -1.079204335 -1.195329068 -2.442598870
##  [36] -2.627984511 -3.982551678 -3.857865933 -3.019737161 -2.747339308
##  [41] -0.528120821 -1.882170996 -1.902074296 -1.608094349 -2.178802110
##  [46] -2.379534243 -2.732845736 -3.094315602 -2.617555067 -2.424490611
##  [51] -3.541787576 -2.837867835 -3.236181057 -3.200626105 -2.409858787
##  [56] -1.281998796  0.524846317 -0.767330024  1.327213880 -0.647667612
##  [61]  0.598197434  2.718556265  1.444157230  0.596156288  0.579304834
##  [66]  2.185968123  0.070237292  1.840139450  2.263681974  1.836341674
##  [71]  1.377800070  0.600699632  0.209385897  0.873119442  2.548707762
##  [76]  1.295579357 -0.233169716 -0.581050764 -0.078897563 -0.472718049
##  [81] -0.429928495 -0.479501934 -1.698038552 -1.118706833 -0.048728870
##  [86]  0.449502910  0.765003032  0.069670123 -0.003758103 -1.182472906
##  [91] -0.645146892 -0.303872027  1.424998615  1.653238155  0.616035357
##  [96]  0.994215607 -0.514293169  0.819900164  1.280008202  2.925101239
## [101]  2.133075794  1.176839671  1.081028488  0.273404396 -0.473090691
## [106] -0.014875187 -0.998320358 -0.333949829 -0.011670725 -0.124730445
## [111] -0.260633986 -0.804332834 -1.564060446 -0.093622587 -0.337260856
## [116]  0.643785672 -0.989847187 -0.197140045  0.376626847  0.122609038
## [121] -0.054762280 -0.784765979  1.654826542  1.420961528  2.865654375
## [126]  1.797079134  0.840261143 -0.733741722 -0.834918463 -0.337906043
## [131]  0.677753633  0.524045743 -0.774374715  0.386336120 -1.611807818
## [136] -1.094488933 -1.185724359 -2.760006013 -0.697090356 -1.523417976
## [141] -1.235163709  0.472882443  0.626082891  0.299186237  0.788572475
## [146]  0.853395292  2.247268589  1.570206756  1.740829719  1.532008186
## [151]  0.736932389  0.772487295  2.172374770  0.365092370  0.738781138
## [156]  1.804539704  0.815404992 -0.284772371 -0.849088793 -0.871625900
## [161] -1.452980782 -1.161454963 -1.285743344 -1.058213462 -0.379199302
## [166]  0.223390785  1.714061276  0.833015141  0.438479913  1.856848702
## [171]  2.720449731  1.774838644  1.098851949 -0.917841714  1.172111931
## [176] -0.435094811 -1.106887814  2.403303017  1.215295254  1.055049620
## [181] -1.961635662 -0.869598495  0.148905355  0.314401894  1.099304179
## [186]  2.596264669  2.687101684  1.354066761  1.918633896  1.031714026
## [191]  0.361513003 -2.468659348 -1.951673926 -0.981754197  1.286820656
## [196]  0.947754103  1.351451386 -0.100626697  0.382631637 -1.907047063
## [201] -0.391770383  0.119474174  0.166896926  0.808076813  0.749098821
## [206]  1.296627135  2.640596958  2.691986747  1.906776723  0.377336746
## [211]  0.988081540  0.169272882  1.775745851 -0.685353438 -0.403279337
## [216]  0.083298017 -0.190743395 -0.684863209 -0.685301353  0.149912782
## [221]  0.833068101  1.106729238  2.993461760  2.891574300  2.332189230
## [226]  1.084639381  3.927897667  2.858292210  1.530405295  1.523353172
## [231]  0.743364345  0.401648589 -0.584006177 -0.094828026  0.154944990
## [236] -1.019035233 -3.711680751 -2.314522075 -1.870079357 -0.803670320
## [241] -0.716715863 -0.105693101 -1.293961898  0.043055688  0.481624195
## [246]  0.501074304  1.704136427  1.356751546  1.283567328  1.181177877
## [251]  1.284232981  1.938475972  1.678274979  1.890031299  0.144297091
## [256]  0.079657288  1.545657652 -0.435143467  0.349628185  0.492788204
## [261]  1.292123061  0.395742435  0.614921269 -1.376645945 -0.226742672
## [266] -1.055265554 -0.811627936 -1.804632361 -0.679706446 -0.034200180
## [271] -0.457655268  1.589343394  1.373700014  1.953351259  3.300818634
## [276]  1.389965960  2.163765979  2.346456796  1.599810798  1.588249116
## [281]  0.102264815  0.838949778 -0.261042480  0.850951578 -0.438163491
## [286]  0.270506057 -0.798902323 -0.591113129 -2.008196040 -0.993886613
## [291]  0.086860875  0.027900638 -1.734906719 -1.482406929  0.567858229
## [296]  1.797253114 -0.162838565 -0.088671919  0.276721777  0.439782725

B. Menggunakan arima.sim

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] -1.51198789  0.14622636 -1.18196985  0.56474307 -0.60306545  0.10388597
##   [7]  0.83003262 -0.08294885  0.67897065  0.23492188 -0.88195786 -0.66407416
##  [13]  1.11136122  0.20873461 -0.49114292 -0.25784746  0.10298930  0.95524977
##  [19]  1.64218262  1.11266366  2.04934360  0.48294459 -1.69317239 -1.22168070
##  [25] -1.46533032 -3.29303745 -1.37711303 -2.13093915 -1.56694617 -2.79676390
##  [31] -1.16424698  0.74975075 -0.73605113 -0.33063433  1.63618567  1.68578230
##  [37]  3.08318771  1.87351626  1.40113562  0.56563940  1.99762053 -0.17390039
##  [43]  0.61988813  0.22884545  2.49024215  0.68285644 -0.66981152  0.03429730
##  [49] -0.15646235 -0.91049678 -0.35424977 -0.63474899 -1.06698309 -0.15960541
##  [55] -0.62486164 -2.17933215 -3.86637965 -2.94963843 -0.79390827 -0.14875244
##  [61]  0.98189570  1.44370281  1.23399457 -0.60132478  0.15170631  1.55281629
##  [67] -2.58931413 -1.76544609 -0.29812123  0.02659519  0.74306775  0.83395242
##  [73]  1.10442287  0.73364504 -0.32878204 -1.24447710 -0.65184209 -0.99620958
##  [79] -1.52783762 -0.54571941 -0.42498249  1.14164792 -0.63567504 -0.60729602
##  [85] -0.50573010 -1.78211434 -1.27690906 -1.70304857 -3.25454510 -2.25171943
##  [91] -2.31084090 -0.47275414 -1.30261417 -0.18834632 -0.21206670 -1.38056283
##  [97] -0.35855078 -0.56147408 -0.18638521  0.45254743  0.30295959  1.82714845
## [103]  1.08971958 -0.34370956  0.78795392 -0.89766657 -2.21013663 -2.09453802
## [109] -2.23397357 -2.14340031  0.08826470  1.25105173  1.36926990 -0.33898963
## [115]  0.12750572  0.48307617  0.13001173  0.33336658 -0.75210828 -1.59700113
## [121]  0.45884352  0.17739422 -0.22793183  0.24678415  2.14028668  1.48216713
## [127]  2.58054554  2.95425051  1.58605822  2.14642094  0.73922129 -0.67476095
## [133] -1.39120201 -0.97927367  1.02918519  0.42354658 -0.38522765  0.12247046
## [139]  0.68216489 -0.92962519 -1.38305984 -2.81906245 -2.95570378 -2.92910319
## [145] -2.34760812 -0.34953064  0.24435449  0.32524543 -0.35514785 -0.15273178
## [151]  0.40021679 -0.33447128  0.97187785  1.51649823 -0.21387994 -0.55055164
## [157]  0.88868693 -1.35298674 -0.07904609 -0.07662163  3.14178116 -1.17411409
## [163] -0.79949661  0.03945755  1.53415596  1.61465657 -0.31420896  2.40521501
## [169] -0.61750051 -0.94072334 -0.63700216  1.71894116  1.23838673  1.69337765
## [175]  2.82244377  2.73467738  0.70708957  1.61020648  0.83730116  2.52329977
## [181]  1.18566544 -0.42961435  0.51416028  0.52566093  0.34803618 -0.77740005
## [187] -1.15800745 -0.74710945  0.43295393 -0.29740264 -0.93356001 -3.23046356
## [193] -1.30769394 -0.87259936  0.61135239  1.59787897  0.77815390  2.00716647
## [199]  1.16052756  0.30528700 -0.46344759 -0.51760749 -0.12401382 -0.19292981
## [205]  0.07961012  0.20016177  0.83060226  0.18215171  1.89254377  1.42039611
## [211] -0.10482904 -0.04498510  0.47242469 -0.18384001  0.34755998  0.57140785
## [217]  1.65869361  0.29193246  0.46082409 -0.27889392 -1.17441501 -2.49195660
## [223] -1.28533225 -0.53949222  0.11234560 -1.44171846 -1.82806796 -2.34353187
## [229] -2.22605103 -1.41153407 -0.55649381 -1.37558637 -3.66343878 -1.15301318
## [235] -0.69390958 -1.27842813 -1.85165732 -1.48150548 -1.00297764 -0.07458915
## [241]  1.15220499 -0.28769873  0.37731448  1.46529352 -0.09323250  0.02367904
## [247] -1.77827501 -0.59697944 -1.29533649 -1.69200177 -1.88504565 -0.83641981
## [253] -2.95768804 -2.07163888 -2.64107471 -2.69698416 -1.40207239 -0.88867876
## [259] -0.83177421 -0.05610560 -0.79651254 -2.43277504 -0.22126875 -0.82788238
## [265] -0.82328371 -0.41970040  0.39142528  0.53785953  1.27448022  0.79094661
## [271]  0.14608371 -0.06921823  0.81752360 -0.45435064 -1.01728070 -0.28603176
## [277]  0.26600129 -1.61528894  0.03025442 -0.29600544 -0.32320713  0.88614975
## [283]  1.85782832 -0.04125533  1.36259238  0.04097593  0.42536776  0.70180513
## [289]  0.56915374 -1.03792656 -0.91153431  0.87631077  0.42864214 -0.44624070
## [295] -0.79332063  0.57165763  0.47324818 -0.54623092 -0.17220061  0.40132402

Plot Simulasi AR(2)

# Plot Simulasi AR(2)
ts.plot(ar2, main = "Simulasi AR(2)", ylab = "Yt")

Plot ACF (Autocorrelation Function)

# Plot ACF 
acf(ar2, main = "ACF AR(2)")

Plot ACF untuk model AR(2) menunjukkan bahwa adanya tails off

Plot PACF (Partial Autocorrelation Function)

# Plot PACF 
pacf(ar2, main = "PACF AR(2)")

Plot PACF untuk model AR(2) menunjukkan adanya cut off pada lag 1

Plot EACF (Extended Autocorrelation Function)

# Menghitung EACF
library(TSA)
eacf(ar2)
## AR/MA
##   0 1 2 3 4 5 6 7 8 9 10 11 12 13
## 0 x x x x o o o o o o o  o  o  o 
## 1 x o o x o o o o o o o  o  o  o 
## 2 x o o x 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 x o o o o o o o  o  o  o 
## 5 o x o x o o o o o o o  o  o  o 
## 6 o x x o x o o o o o o  o  o  o 
## 7 x o o o x x o o o o o  o  o  o

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

Scatterplot

# Buat lag
yt_ar2   = ar2[4:n]       # Yt
yt_1_ar2 = ar2[3:(n-1)]   # Yt-1
yt_2_ar2 = ar2[2:(n-2)]   # Yt-2
yt_3_ar2 = ar2[1:(n-3)]   # Yt-3
# Perbandingan Yt dengan Yt-1
yt_ar2
##   [1]  0.56474307 -0.60306545  0.10388597  0.83003262 -0.08294885  0.67897065
##   [7]  0.23492188 -0.88195786 -0.66407416  1.11136122  0.20873461 -0.49114292
##  [13] -0.25784746  0.10298930  0.95524977  1.64218262  1.11266366  2.04934360
##  [19]  0.48294459 -1.69317239 -1.22168070 -1.46533032 -3.29303745 -1.37711303
##  [25] -2.13093915 -1.56694617 -2.79676390 -1.16424698  0.74975075 -0.73605113
##  [31] -0.33063433  1.63618567  1.68578230  3.08318771  1.87351626  1.40113562
##  [37]  0.56563940  1.99762053 -0.17390039  0.61988813  0.22884545  2.49024215
##  [43]  0.68285644 -0.66981152  0.03429730 -0.15646235 -0.91049678 -0.35424977
##  [49] -0.63474899 -1.06698309 -0.15960541 -0.62486164 -2.17933215 -3.86637965
##  [55] -2.94963843 -0.79390827 -0.14875244  0.98189570  1.44370281  1.23399457
##  [61] -0.60132478  0.15170631  1.55281629 -2.58931413 -1.76544609 -0.29812123
##  [67]  0.02659519  0.74306775  0.83395242  1.10442287  0.73364504 -0.32878204
##  [73] -1.24447710 -0.65184209 -0.99620958 -1.52783762 -0.54571941 -0.42498249
##  [79]  1.14164792 -0.63567504 -0.60729602 -0.50573010 -1.78211434 -1.27690906
##  [85] -1.70304857 -3.25454510 -2.25171943 -2.31084090 -0.47275414 -1.30261417
##  [91] -0.18834632 -0.21206670 -1.38056283 -0.35855078 -0.56147408 -0.18638521
##  [97]  0.45254743  0.30295959  1.82714845  1.08971958 -0.34370956  0.78795392
## [103] -0.89766657 -2.21013663 -2.09453802 -2.23397357 -2.14340031  0.08826470
## [109]  1.25105173  1.36926990 -0.33898963  0.12750572  0.48307617  0.13001173
## [115]  0.33336658 -0.75210828 -1.59700113  0.45884352  0.17739422 -0.22793183
## [121]  0.24678415  2.14028668  1.48216713  2.58054554  2.95425051  1.58605822
## [127]  2.14642094  0.73922129 -0.67476095 -1.39120201 -0.97927367  1.02918519
## [133]  0.42354658 -0.38522765  0.12247046  0.68216489 -0.92962519 -1.38305984
## [139] -2.81906245 -2.95570378 -2.92910319 -2.34760812 -0.34953064  0.24435449
## [145]  0.32524543 -0.35514785 -0.15273178  0.40021679 -0.33447128  0.97187785
## [151]  1.51649823 -0.21387994 -0.55055164  0.88868693 -1.35298674 -0.07904609
## [157] -0.07662163  3.14178116 -1.17411409 -0.79949661  0.03945755  1.53415596
## [163]  1.61465657 -0.31420896  2.40521501 -0.61750051 -0.94072334 -0.63700216
## [169]  1.71894116  1.23838673  1.69337765  2.82244377  2.73467738  0.70708957
## [175]  1.61020648  0.83730116  2.52329977  1.18566544 -0.42961435  0.51416028
## [181]  0.52566093  0.34803618 -0.77740005 -1.15800745 -0.74710945  0.43295393
## [187] -0.29740264 -0.93356001 -3.23046356 -1.30769394 -0.87259936  0.61135239
## [193]  1.59787897  0.77815390  2.00716647  1.16052756  0.30528700 -0.46344759
## [199] -0.51760749 -0.12401382 -0.19292981  0.07961012  0.20016177  0.83060226
## [205]  0.18215171  1.89254377  1.42039611 -0.10482904 -0.04498510  0.47242469
## [211] -0.18384001  0.34755998  0.57140785  1.65869361  0.29193246  0.46082409
## [217] -0.27889392 -1.17441501 -2.49195660 -1.28533225 -0.53949222  0.11234560
## [223] -1.44171846 -1.82806796 -2.34353187 -2.22605103 -1.41153407 -0.55649381
## [229] -1.37558637 -3.66343878 -1.15301318 -0.69390958 -1.27842813 -1.85165732
## [235] -1.48150548 -1.00297764 -0.07458915  1.15220499 -0.28769873  0.37731448
## [241]  1.46529352 -0.09323250  0.02367904 -1.77827501 -0.59697944 -1.29533649
## [247] -1.69200177 -1.88504565 -0.83641981 -2.95768804 -2.07163888 -2.64107471
## [253] -2.69698416 -1.40207239 -0.88867876 -0.83177421 -0.05610560 -0.79651254
## [259] -2.43277504 -0.22126875 -0.82788238 -0.82328371 -0.41970040  0.39142528
## [265]  0.53785953  1.27448022  0.79094661  0.14608371 -0.06921823  0.81752360
## [271] -0.45435064 -1.01728070 -0.28603176  0.26600129 -1.61528894  0.03025442
## [277] -0.29600544 -0.32320713  0.88614975  1.85782832 -0.04125533  1.36259238
## [283]  0.04097593  0.42536776  0.70180513  0.56915374 -1.03792656 -0.91153431
## [289]  0.87631077  0.42864214 -0.44624070 -0.79332063  0.57165763  0.47324818
## [295] -0.54623092 -0.17220061  0.40132402
yt_1_ar2
##   [1] -1.18196985  0.56474307 -0.60306545  0.10388597  0.83003262 -0.08294885
##   [7]  0.67897065  0.23492188 -0.88195786 -0.66407416  1.11136122  0.20873461
##  [13] -0.49114292 -0.25784746  0.10298930  0.95524977  1.64218262  1.11266366
##  [19]  2.04934360  0.48294459 -1.69317239 -1.22168070 -1.46533032 -3.29303745
##  [25] -1.37711303 -2.13093915 -1.56694617 -2.79676390 -1.16424698  0.74975075
##  [31] -0.73605113 -0.33063433  1.63618567  1.68578230  3.08318771  1.87351626
##  [37]  1.40113562  0.56563940  1.99762053 -0.17390039  0.61988813  0.22884545
##  [43]  2.49024215  0.68285644 -0.66981152  0.03429730 -0.15646235 -0.91049678
##  [49] -0.35424977 -0.63474899 -1.06698309 -0.15960541 -0.62486164 -2.17933215
##  [55] -3.86637965 -2.94963843 -0.79390827 -0.14875244  0.98189570  1.44370281
##  [61]  1.23399457 -0.60132478  0.15170631  1.55281629 -2.58931413 -1.76544609
##  [67] -0.29812123  0.02659519  0.74306775  0.83395242  1.10442287  0.73364504
##  [73] -0.32878204 -1.24447710 -0.65184209 -0.99620958 -1.52783762 -0.54571941
##  [79] -0.42498249  1.14164792 -0.63567504 -0.60729602 -0.50573010 -1.78211434
##  [85] -1.27690906 -1.70304857 -3.25454510 -2.25171943 -2.31084090 -0.47275414
##  [91] -1.30261417 -0.18834632 -0.21206670 -1.38056283 -0.35855078 -0.56147408
##  [97] -0.18638521  0.45254743  0.30295959  1.82714845  1.08971958 -0.34370956
## [103]  0.78795392 -0.89766657 -2.21013663 -2.09453802 -2.23397357 -2.14340031
## [109]  0.08826470  1.25105173  1.36926990 -0.33898963  0.12750572  0.48307617
## [115]  0.13001173  0.33336658 -0.75210828 -1.59700113  0.45884352  0.17739422
## [121] -0.22793183  0.24678415  2.14028668  1.48216713  2.58054554  2.95425051
## [127]  1.58605822  2.14642094  0.73922129 -0.67476095 -1.39120201 -0.97927367
## [133]  1.02918519  0.42354658 -0.38522765  0.12247046  0.68216489 -0.92962519
## [139] -1.38305984 -2.81906245 -2.95570378 -2.92910319 -2.34760812 -0.34953064
## [145]  0.24435449  0.32524543 -0.35514785 -0.15273178  0.40021679 -0.33447128
## [151]  0.97187785  1.51649823 -0.21387994 -0.55055164  0.88868693 -1.35298674
## [157] -0.07904609 -0.07662163  3.14178116 -1.17411409 -0.79949661  0.03945755
## [163]  1.53415596  1.61465657 -0.31420896  2.40521501 -0.61750051 -0.94072334
## [169] -0.63700216  1.71894116  1.23838673  1.69337765  2.82244377  2.73467738
## [175]  0.70708957  1.61020648  0.83730116  2.52329977  1.18566544 -0.42961435
## [181]  0.51416028  0.52566093  0.34803618 -0.77740005 -1.15800745 -0.74710945
## [187]  0.43295393 -0.29740264 -0.93356001 -3.23046356 -1.30769394 -0.87259936
## [193]  0.61135239  1.59787897  0.77815390  2.00716647  1.16052756  0.30528700
## [199] -0.46344759 -0.51760749 -0.12401382 -0.19292981  0.07961012  0.20016177
## [205]  0.83060226  0.18215171  1.89254377  1.42039611 -0.10482904 -0.04498510
## [211]  0.47242469 -0.18384001  0.34755998  0.57140785  1.65869361  0.29193246
## [217]  0.46082409 -0.27889392 -1.17441501 -2.49195660 -1.28533225 -0.53949222
## [223]  0.11234560 -1.44171846 -1.82806796 -2.34353187 -2.22605103 -1.41153407
## [229] -0.55649381 -1.37558637 -3.66343878 -1.15301318 -0.69390958 -1.27842813
## [235] -1.85165732 -1.48150548 -1.00297764 -0.07458915  1.15220499 -0.28769873
## [241]  0.37731448  1.46529352 -0.09323250  0.02367904 -1.77827501 -0.59697944
## [247] -1.29533649 -1.69200177 -1.88504565 -0.83641981 -2.95768804 -2.07163888
## [253] -2.64107471 -2.69698416 -1.40207239 -0.88867876 -0.83177421 -0.05610560
## [259] -0.79651254 -2.43277504 -0.22126875 -0.82788238 -0.82328371 -0.41970040
## [265]  0.39142528  0.53785953  1.27448022  0.79094661  0.14608371 -0.06921823
## [271]  0.81752360 -0.45435064 -1.01728070 -0.28603176  0.26600129 -1.61528894
## [277]  0.03025442 -0.29600544 -0.32320713  0.88614975  1.85782832 -0.04125533
## [283]  1.36259238  0.04097593  0.42536776  0.70180513  0.56915374 -1.03792656
## [289] -0.91153431  0.87631077  0.42864214 -0.44624070 -0.79332063  0.57165763
## [295]  0.47324818 -0.54623092 -0.17220061
# Perbandingan Yt dengan Yt-2
yt_ar2
##   [1]  0.56474307 -0.60306545  0.10388597  0.83003262 -0.08294885  0.67897065
##   [7]  0.23492188 -0.88195786 -0.66407416  1.11136122  0.20873461 -0.49114292
##  [13] -0.25784746  0.10298930  0.95524977  1.64218262  1.11266366  2.04934360
##  [19]  0.48294459 -1.69317239 -1.22168070 -1.46533032 -3.29303745 -1.37711303
##  [25] -2.13093915 -1.56694617 -2.79676390 -1.16424698  0.74975075 -0.73605113
##  [31] -0.33063433  1.63618567  1.68578230  3.08318771  1.87351626  1.40113562
##  [37]  0.56563940  1.99762053 -0.17390039  0.61988813  0.22884545  2.49024215
##  [43]  0.68285644 -0.66981152  0.03429730 -0.15646235 -0.91049678 -0.35424977
##  [49] -0.63474899 -1.06698309 -0.15960541 -0.62486164 -2.17933215 -3.86637965
##  [55] -2.94963843 -0.79390827 -0.14875244  0.98189570  1.44370281  1.23399457
##  [61] -0.60132478  0.15170631  1.55281629 -2.58931413 -1.76544609 -0.29812123
##  [67]  0.02659519  0.74306775  0.83395242  1.10442287  0.73364504 -0.32878204
##  [73] -1.24447710 -0.65184209 -0.99620958 -1.52783762 -0.54571941 -0.42498249
##  [79]  1.14164792 -0.63567504 -0.60729602 -0.50573010 -1.78211434 -1.27690906
##  [85] -1.70304857 -3.25454510 -2.25171943 -2.31084090 -0.47275414 -1.30261417
##  [91] -0.18834632 -0.21206670 -1.38056283 -0.35855078 -0.56147408 -0.18638521
##  [97]  0.45254743  0.30295959  1.82714845  1.08971958 -0.34370956  0.78795392
## [103] -0.89766657 -2.21013663 -2.09453802 -2.23397357 -2.14340031  0.08826470
## [109]  1.25105173  1.36926990 -0.33898963  0.12750572  0.48307617  0.13001173
## [115]  0.33336658 -0.75210828 -1.59700113  0.45884352  0.17739422 -0.22793183
## [121]  0.24678415  2.14028668  1.48216713  2.58054554  2.95425051  1.58605822
## [127]  2.14642094  0.73922129 -0.67476095 -1.39120201 -0.97927367  1.02918519
## [133]  0.42354658 -0.38522765  0.12247046  0.68216489 -0.92962519 -1.38305984
## [139] -2.81906245 -2.95570378 -2.92910319 -2.34760812 -0.34953064  0.24435449
## [145]  0.32524543 -0.35514785 -0.15273178  0.40021679 -0.33447128  0.97187785
## [151]  1.51649823 -0.21387994 -0.55055164  0.88868693 -1.35298674 -0.07904609
## [157] -0.07662163  3.14178116 -1.17411409 -0.79949661  0.03945755  1.53415596
## [163]  1.61465657 -0.31420896  2.40521501 -0.61750051 -0.94072334 -0.63700216
## [169]  1.71894116  1.23838673  1.69337765  2.82244377  2.73467738  0.70708957
## [175]  1.61020648  0.83730116  2.52329977  1.18566544 -0.42961435  0.51416028
## [181]  0.52566093  0.34803618 -0.77740005 -1.15800745 -0.74710945  0.43295393
## [187] -0.29740264 -0.93356001 -3.23046356 -1.30769394 -0.87259936  0.61135239
## [193]  1.59787897  0.77815390  2.00716647  1.16052756  0.30528700 -0.46344759
## [199] -0.51760749 -0.12401382 -0.19292981  0.07961012  0.20016177  0.83060226
## [205]  0.18215171  1.89254377  1.42039611 -0.10482904 -0.04498510  0.47242469
## [211] -0.18384001  0.34755998  0.57140785  1.65869361  0.29193246  0.46082409
## [217] -0.27889392 -1.17441501 -2.49195660 -1.28533225 -0.53949222  0.11234560
## [223] -1.44171846 -1.82806796 -2.34353187 -2.22605103 -1.41153407 -0.55649381
## [229] -1.37558637 -3.66343878 -1.15301318 -0.69390958 -1.27842813 -1.85165732
## [235] -1.48150548 -1.00297764 -0.07458915  1.15220499 -0.28769873  0.37731448
## [241]  1.46529352 -0.09323250  0.02367904 -1.77827501 -0.59697944 -1.29533649
## [247] -1.69200177 -1.88504565 -0.83641981 -2.95768804 -2.07163888 -2.64107471
## [253] -2.69698416 -1.40207239 -0.88867876 -0.83177421 -0.05610560 -0.79651254
## [259] -2.43277504 -0.22126875 -0.82788238 -0.82328371 -0.41970040  0.39142528
## [265]  0.53785953  1.27448022  0.79094661  0.14608371 -0.06921823  0.81752360
## [271] -0.45435064 -1.01728070 -0.28603176  0.26600129 -1.61528894  0.03025442
## [277] -0.29600544 -0.32320713  0.88614975  1.85782832 -0.04125533  1.36259238
## [283]  0.04097593  0.42536776  0.70180513  0.56915374 -1.03792656 -0.91153431
## [289]  0.87631077  0.42864214 -0.44624070 -0.79332063  0.57165763  0.47324818
## [295] -0.54623092 -0.17220061  0.40132402
yt_2_ar2
##   [1]  0.14622636 -1.18196985  0.56474307 -0.60306545  0.10388597  0.83003262
##   [7] -0.08294885  0.67897065  0.23492188 -0.88195786 -0.66407416  1.11136122
##  [13]  0.20873461 -0.49114292 -0.25784746  0.10298930  0.95524977  1.64218262
##  [19]  1.11266366  2.04934360  0.48294459 -1.69317239 -1.22168070 -1.46533032
##  [25] -3.29303745 -1.37711303 -2.13093915 -1.56694617 -2.79676390 -1.16424698
##  [31]  0.74975075 -0.73605113 -0.33063433  1.63618567  1.68578230  3.08318771
##  [37]  1.87351626  1.40113562  0.56563940  1.99762053 -0.17390039  0.61988813
##  [43]  0.22884545  2.49024215  0.68285644 -0.66981152  0.03429730 -0.15646235
##  [49] -0.91049678 -0.35424977 -0.63474899 -1.06698309 -0.15960541 -0.62486164
##  [55] -2.17933215 -3.86637965 -2.94963843 -0.79390827 -0.14875244  0.98189570
##  [61]  1.44370281  1.23399457 -0.60132478  0.15170631  1.55281629 -2.58931413
##  [67] -1.76544609 -0.29812123  0.02659519  0.74306775  0.83395242  1.10442287
##  [73]  0.73364504 -0.32878204 -1.24447710 -0.65184209 -0.99620958 -1.52783762
##  [79] -0.54571941 -0.42498249  1.14164792 -0.63567504 -0.60729602 -0.50573010
##  [85] -1.78211434 -1.27690906 -1.70304857 -3.25454510 -2.25171943 -2.31084090
##  [91] -0.47275414 -1.30261417 -0.18834632 -0.21206670 -1.38056283 -0.35855078
##  [97] -0.56147408 -0.18638521  0.45254743  0.30295959  1.82714845  1.08971958
## [103] -0.34370956  0.78795392 -0.89766657 -2.21013663 -2.09453802 -2.23397357
## [109] -2.14340031  0.08826470  1.25105173  1.36926990 -0.33898963  0.12750572
## [115]  0.48307617  0.13001173  0.33336658 -0.75210828 -1.59700113  0.45884352
## [121]  0.17739422 -0.22793183  0.24678415  2.14028668  1.48216713  2.58054554
## [127]  2.95425051  1.58605822  2.14642094  0.73922129 -0.67476095 -1.39120201
## [133] -0.97927367  1.02918519  0.42354658 -0.38522765  0.12247046  0.68216489
## [139] -0.92962519 -1.38305984 -2.81906245 -2.95570378 -2.92910319 -2.34760812
## [145] -0.34953064  0.24435449  0.32524543 -0.35514785 -0.15273178  0.40021679
## [151] -0.33447128  0.97187785  1.51649823 -0.21387994 -0.55055164  0.88868693
## [157] -1.35298674 -0.07904609 -0.07662163  3.14178116 -1.17411409 -0.79949661
## [163]  0.03945755  1.53415596  1.61465657 -0.31420896  2.40521501 -0.61750051
## [169] -0.94072334 -0.63700216  1.71894116  1.23838673  1.69337765  2.82244377
## [175]  2.73467738  0.70708957  1.61020648  0.83730116  2.52329977  1.18566544
## [181] -0.42961435  0.51416028  0.52566093  0.34803618 -0.77740005 -1.15800745
## [187] -0.74710945  0.43295393 -0.29740264 -0.93356001 -3.23046356 -1.30769394
## [193] -0.87259936  0.61135239  1.59787897  0.77815390  2.00716647  1.16052756
## [199]  0.30528700 -0.46344759 -0.51760749 -0.12401382 -0.19292981  0.07961012
## [205]  0.20016177  0.83060226  0.18215171  1.89254377  1.42039611 -0.10482904
## [211] -0.04498510  0.47242469 -0.18384001  0.34755998  0.57140785  1.65869361
## [217]  0.29193246  0.46082409 -0.27889392 -1.17441501 -2.49195660 -1.28533225
## [223] -0.53949222  0.11234560 -1.44171846 -1.82806796 -2.34353187 -2.22605103
## [229] -1.41153407 -0.55649381 -1.37558637 -3.66343878 -1.15301318 -0.69390958
## [235] -1.27842813 -1.85165732 -1.48150548 -1.00297764 -0.07458915  1.15220499
## [241] -0.28769873  0.37731448  1.46529352 -0.09323250  0.02367904 -1.77827501
## [247] -0.59697944 -1.29533649 -1.69200177 -1.88504565 -0.83641981 -2.95768804
## [253] -2.07163888 -2.64107471 -2.69698416 -1.40207239 -0.88867876 -0.83177421
## [259] -0.05610560 -0.79651254 -2.43277504 -0.22126875 -0.82788238 -0.82328371
## [265] -0.41970040  0.39142528  0.53785953  1.27448022  0.79094661  0.14608371
## [271] -0.06921823  0.81752360 -0.45435064 -1.01728070 -0.28603176  0.26600129
## [277] -1.61528894  0.03025442 -0.29600544 -0.32320713  0.88614975  1.85782832
## [283] -0.04125533  1.36259238  0.04097593  0.42536776  0.70180513  0.56915374
## [289] -1.03792656 -0.91153431  0.87631077  0.42864214 -0.44624070 -0.79332063
## [295]  0.57165763  0.47324818 -0.54623092
# Perbandingan Yt dengan Yt-3
yt_ar2
##   [1]  0.56474307 -0.60306545  0.10388597  0.83003262 -0.08294885  0.67897065
##   [7]  0.23492188 -0.88195786 -0.66407416  1.11136122  0.20873461 -0.49114292
##  [13] -0.25784746  0.10298930  0.95524977  1.64218262  1.11266366  2.04934360
##  [19]  0.48294459 -1.69317239 -1.22168070 -1.46533032 -3.29303745 -1.37711303
##  [25] -2.13093915 -1.56694617 -2.79676390 -1.16424698  0.74975075 -0.73605113
##  [31] -0.33063433  1.63618567  1.68578230  3.08318771  1.87351626  1.40113562
##  [37]  0.56563940  1.99762053 -0.17390039  0.61988813  0.22884545  2.49024215
##  [43]  0.68285644 -0.66981152  0.03429730 -0.15646235 -0.91049678 -0.35424977
##  [49] -0.63474899 -1.06698309 -0.15960541 -0.62486164 -2.17933215 -3.86637965
##  [55] -2.94963843 -0.79390827 -0.14875244  0.98189570  1.44370281  1.23399457
##  [61] -0.60132478  0.15170631  1.55281629 -2.58931413 -1.76544609 -0.29812123
##  [67]  0.02659519  0.74306775  0.83395242  1.10442287  0.73364504 -0.32878204
##  [73] -1.24447710 -0.65184209 -0.99620958 -1.52783762 -0.54571941 -0.42498249
##  [79]  1.14164792 -0.63567504 -0.60729602 -0.50573010 -1.78211434 -1.27690906
##  [85] -1.70304857 -3.25454510 -2.25171943 -2.31084090 -0.47275414 -1.30261417
##  [91] -0.18834632 -0.21206670 -1.38056283 -0.35855078 -0.56147408 -0.18638521
##  [97]  0.45254743  0.30295959  1.82714845  1.08971958 -0.34370956  0.78795392
## [103] -0.89766657 -2.21013663 -2.09453802 -2.23397357 -2.14340031  0.08826470
## [109]  1.25105173  1.36926990 -0.33898963  0.12750572  0.48307617  0.13001173
## [115]  0.33336658 -0.75210828 -1.59700113  0.45884352  0.17739422 -0.22793183
## [121]  0.24678415  2.14028668  1.48216713  2.58054554  2.95425051  1.58605822
## [127]  2.14642094  0.73922129 -0.67476095 -1.39120201 -0.97927367  1.02918519
## [133]  0.42354658 -0.38522765  0.12247046  0.68216489 -0.92962519 -1.38305984
## [139] -2.81906245 -2.95570378 -2.92910319 -2.34760812 -0.34953064  0.24435449
## [145]  0.32524543 -0.35514785 -0.15273178  0.40021679 -0.33447128  0.97187785
## [151]  1.51649823 -0.21387994 -0.55055164  0.88868693 -1.35298674 -0.07904609
## [157] -0.07662163  3.14178116 -1.17411409 -0.79949661  0.03945755  1.53415596
## [163]  1.61465657 -0.31420896  2.40521501 -0.61750051 -0.94072334 -0.63700216
## [169]  1.71894116  1.23838673  1.69337765  2.82244377  2.73467738  0.70708957
## [175]  1.61020648  0.83730116  2.52329977  1.18566544 -0.42961435  0.51416028
## [181]  0.52566093  0.34803618 -0.77740005 -1.15800745 -0.74710945  0.43295393
## [187] -0.29740264 -0.93356001 -3.23046356 -1.30769394 -0.87259936  0.61135239
## [193]  1.59787897  0.77815390  2.00716647  1.16052756  0.30528700 -0.46344759
## [199] -0.51760749 -0.12401382 -0.19292981  0.07961012  0.20016177  0.83060226
## [205]  0.18215171  1.89254377  1.42039611 -0.10482904 -0.04498510  0.47242469
## [211] -0.18384001  0.34755998  0.57140785  1.65869361  0.29193246  0.46082409
## [217] -0.27889392 -1.17441501 -2.49195660 -1.28533225 -0.53949222  0.11234560
## [223] -1.44171846 -1.82806796 -2.34353187 -2.22605103 -1.41153407 -0.55649381
## [229] -1.37558637 -3.66343878 -1.15301318 -0.69390958 -1.27842813 -1.85165732
## [235] -1.48150548 -1.00297764 -0.07458915  1.15220499 -0.28769873  0.37731448
## [241]  1.46529352 -0.09323250  0.02367904 -1.77827501 -0.59697944 -1.29533649
## [247] -1.69200177 -1.88504565 -0.83641981 -2.95768804 -2.07163888 -2.64107471
## [253] -2.69698416 -1.40207239 -0.88867876 -0.83177421 -0.05610560 -0.79651254
## [259] -2.43277504 -0.22126875 -0.82788238 -0.82328371 -0.41970040  0.39142528
## [265]  0.53785953  1.27448022  0.79094661  0.14608371 -0.06921823  0.81752360
## [271] -0.45435064 -1.01728070 -0.28603176  0.26600129 -1.61528894  0.03025442
## [277] -0.29600544 -0.32320713  0.88614975  1.85782832 -0.04125533  1.36259238
## [283]  0.04097593  0.42536776  0.70180513  0.56915374 -1.03792656 -0.91153431
## [289]  0.87631077  0.42864214 -0.44624070 -0.79332063  0.57165763  0.47324818
## [295] -0.54623092 -0.17220061  0.40132402
yt_3_ar2
##   [1] -1.51198789  0.14622636 -1.18196985  0.56474307 -0.60306545  0.10388597
##   [7]  0.83003262 -0.08294885  0.67897065  0.23492188 -0.88195786 -0.66407416
##  [13]  1.11136122  0.20873461 -0.49114292 -0.25784746  0.10298930  0.95524977
##  [19]  1.64218262  1.11266366  2.04934360  0.48294459 -1.69317239 -1.22168070
##  [25] -1.46533032 -3.29303745 -1.37711303 -2.13093915 -1.56694617 -2.79676390
##  [31] -1.16424698  0.74975075 -0.73605113 -0.33063433  1.63618567  1.68578230
##  [37]  3.08318771  1.87351626  1.40113562  0.56563940  1.99762053 -0.17390039
##  [43]  0.61988813  0.22884545  2.49024215  0.68285644 -0.66981152  0.03429730
##  [49] -0.15646235 -0.91049678 -0.35424977 -0.63474899 -1.06698309 -0.15960541
##  [55] -0.62486164 -2.17933215 -3.86637965 -2.94963843 -0.79390827 -0.14875244
##  [61]  0.98189570  1.44370281  1.23399457 -0.60132478  0.15170631  1.55281629
##  [67] -2.58931413 -1.76544609 -0.29812123  0.02659519  0.74306775  0.83395242
##  [73]  1.10442287  0.73364504 -0.32878204 -1.24447710 -0.65184209 -0.99620958
##  [79] -1.52783762 -0.54571941 -0.42498249  1.14164792 -0.63567504 -0.60729602
##  [85] -0.50573010 -1.78211434 -1.27690906 -1.70304857 -3.25454510 -2.25171943
##  [91] -2.31084090 -0.47275414 -1.30261417 -0.18834632 -0.21206670 -1.38056283
##  [97] -0.35855078 -0.56147408 -0.18638521  0.45254743  0.30295959  1.82714845
## [103]  1.08971958 -0.34370956  0.78795392 -0.89766657 -2.21013663 -2.09453802
## [109] -2.23397357 -2.14340031  0.08826470  1.25105173  1.36926990 -0.33898963
## [115]  0.12750572  0.48307617  0.13001173  0.33336658 -0.75210828 -1.59700113
## [121]  0.45884352  0.17739422 -0.22793183  0.24678415  2.14028668  1.48216713
## [127]  2.58054554  2.95425051  1.58605822  2.14642094  0.73922129 -0.67476095
## [133] -1.39120201 -0.97927367  1.02918519  0.42354658 -0.38522765  0.12247046
## [139]  0.68216489 -0.92962519 -1.38305984 -2.81906245 -2.95570378 -2.92910319
## [145] -2.34760812 -0.34953064  0.24435449  0.32524543 -0.35514785 -0.15273178
## [151]  0.40021679 -0.33447128  0.97187785  1.51649823 -0.21387994 -0.55055164
## [157]  0.88868693 -1.35298674 -0.07904609 -0.07662163  3.14178116 -1.17411409
## [163] -0.79949661  0.03945755  1.53415596  1.61465657 -0.31420896  2.40521501
## [169] -0.61750051 -0.94072334 -0.63700216  1.71894116  1.23838673  1.69337765
## [175]  2.82244377  2.73467738  0.70708957  1.61020648  0.83730116  2.52329977
## [181]  1.18566544 -0.42961435  0.51416028  0.52566093  0.34803618 -0.77740005
## [187] -1.15800745 -0.74710945  0.43295393 -0.29740264 -0.93356001 -3.23046356
## [193] -1.30769394 -0.87259936  0.61135239  1.59787897  0.77815390  2.00716647
## [199]  1.16052756  0.30528700 -0.46344759 -0.51760749 -0.12401382 -0.19292981
## [205]  0.07961012  0.20016177  0.83060226  0.18215171  1.89254377  1.42039611
## [211] -0.10482904 -0.04498510  0.47242469 -0.18384001  0.34755998  0.57140785
## [217]  1.65869361  0.29193246  0.46082409 -0.27889392 -1.17441501 -2.49195660
## [223] -1.28533225 -0.53949222  0.11234560 -1.44171846 -1.82806796 -2.34353187
## [229] -2.22605103 -1.41153407 -0.55649381 -1.37558637 -3.66343878 -1.15301318
## [235] -0.69390958 -1.27842813 -1.85165732 -1.48150548 -1.00297764 -0.07458915
## [241]  1.15220499 -0.28769873  0.37731448  1.46529352 -0.09323250  0.02367904
## [247] -1.77827501 -0.59697944 -1.29533649 -1.69200177 -1.88504565 -0.83641981
## [253] -2.95768804 -2.07163888 -2.64107471 -2.69698416 -1.40207239 -0.88867876
## [259] -0.83177421 -0.05610560 -0.79651254 -2.43277504 -0.22126875 -0.82788238
## [265] -0.82328371 -0.41970040  0.39142528  0.53785953  1.27448022  0.79094661
## [271]  0.14608371 -0.06921823  0.81752360 -0.45435064 -1.01728070 -0.28603176
## [277]  0.26600129 -1.61528894  0.03025442 -0.29600544 -0.32320713  0.88614975
## [283]  1.85782832 -0.04125533  1.36259238  0.04097593  0.42536776  0.70180513
## [289]  0.56915374 -1.03792656 -0.91153431  0.87631077  0.42864214 -0.44624070
## [295] -0.79332063  0.57165763  0.47324818
par(mfrow=c(1,3))
# Scatterplot Yt vs Yt-1
plot(yt_ar2, yt_1_ar2, main="Scatterplot Yt vs Yt-1", xlab="Yt", ylab="Yt-1")

# Scatterplot Yt vs Yt-2
plot(yt_ar2, yt_2_ar2, main="Scatterplot Yt vs Yt-2", xlab="Yt", ylab="Yt-2")

# Scatterplot Yt vs Yt-3
plot(yt_ar2, yt_3_ar2, main="Scatterplot Yt vs Yt-3", xlab="Yt", ylab="Yt-3")

Autokorelasi dari data bangkitan

\(\rho_k\) = \(\phi_1\)\(\rho_{k-1}\)+\(\phi_2\)\(\rho_{k-2}\)

\(\rho_1\) = \(\phi_1\)/1 - \(\phi_2\) ; \(\rho_2\) = \(\phi1\)\(\rho_2\)+\(\rho_2\)

phi1 = 0.5
phi2 = 0.2
rho_theo = numeric(20) # simpan beberapa lag

# rho0
rho_theo[1] = 1            
# rho1
rho_theo[2] = phi1 / (1 - phi2)        
# rho2
rho_theo[3] = phi1 * rho_theo[2] + phi2

# rekursi untuk rho_k (k>=3)
for (k in 4:20) {
  rho_theo[k] <- phi1 * rho_theo[k-1] + phi2 * rho_theo[k-2]
}
# tampilkan rho1..rho6
rho_theo[2:7]
## [1] 0.6250000 0.5125000 0.3812500 0.2931250 0.2228125 0.1700312

Autokorelasi dari data empiris

acf_emp = acf(ar2, plot = FALSE)$acf[1:6] # Menampilkan data dari lag 1 sampai lag 5
acf_emp
## [1] 0.60100713 0.41537866 0.29859908 0.19740462 0.05960827 0.01234154

Hasil ACF, PACF, dan EACF menunnjukkan bahwa hasil simulai model AR(2) itu stationer karena

  • ACF tails off

  • PACF cut off di lag 2

  • EACF menunjukkan pola sesuai dengan MA(2) yaitu segitiga nol berada pada ordo MA(0)

3. ARMA(2,2)

Bentuk umum data berpola ARMA:

\[Yt = 0.5 Y_{t-1} + 0.2Y_{t-1} + e_t +0.4e_{t-1} + 0.6*e_{t-2}\]

Di sini akan dibangkitkan data dengan model ARMA(2,2) dengan \(\phi_1 = 0.5\) dan \(\phi_2 = 0.2\) kemudian dengan \(\theta_1 = 0.4\) dan \(\theta_2 = 0.6\) .

A. Menggunakan Teknik Manual

Bangkitkan data dari set.seed

Bangkitkan data AR(2) dengan \(\phi_1 = 0.5\) dan \(\phi_2 = 0.2\) dan \(\theta_1 = 0.4\) dan \(\theta_2 = 0.6\) sebanyak 300 data menggunakan fungsi arima.sim.

set.seed(1234) # Mengatur random seed generator
n = 300 # Banyak data yang akan dibangkitkan

# Koefisien AR dan MA 
phi1 = 0.5 # koefisien AR lag 1
phi2 = 0.2 # koefisien AR lag 2
theta1 = 0.4 # koefisien MA lag 1
theta2 = 0.6 # koefisien MA lag 2
# White noise 
wn = rnorm(n) 

# Vektor kosong berisi n angka nol
y.arma = numeric(n) # Akan diisi dengan data deret waktu Yt 
# Iterasi dari t = 3 sampai t = 300
# Mulai dari t = 3 karena model AR(2) dan MA(2) butuh lag hingga 2
for (i in 3:n) {
  y.arma[i] <- phi1 * y.arma[i-1] +
               phi2 * y.arma[i-2] +
               wn[i] +
               theta1 * wn[i-1] +
               theta2 * wn[i-2]
}

y.arma
##   [1]  0.00000000  0.00000000  0.47117342 -1.50987697 -0.51919349 -1.29128499
##   [7] -0.86432398 -1.16331330 -1.88247016 -2.61769548 -2.85722080 -3.67543572
##  [13] -3.87108611 -3.51570481 -2.01254438 -1.39722573 -1.08054901 -2.00149017
##  [19] -2.72511044 -0.22860399 -0.06120480  0.93612730 -0.10054661  0.12591091
##  [25] -0.73136706 -1.79044069 -1.46225215 -2.75189059 -1.74814288 -2.98064692
##  [31] -1.12111691 -1.75293106 -1.33898765 -2.09046996 -3.56829323 -4.32225209
##  [37] -6.49932813 -7.02769509 -6.95242810 -6.26996407 -3.43890672 -3.74182891
##  [43] -2.97181976 -3.49823015 -3.96328709 -4.21591372 -4.99194225 -5.61517562
##  [49] -5.49498965 -5.32810268 -6.08211738 -5.70927763 -6.49640104 -6.19781946
##  [55] -5.63181804 -4.16631811 -1.43386858 -1.32659085  1.33518960 -0.57718012
##  [61]  1.13545868  2.56923465  2.89049818  2.80495292  1.68426168  2.77538382
##  [67]  1.29220743  3.17981524  3.04188012  3.84589813  3.47054592  2.25362466
##  [73]  1.27634579  1.31729358  3.02358708  2.83893413  1.81428668  0.10302896
##  [79] -0.45121970 -0.85290753 -0.66635425 -0.93510416 -2.14779642 -2.08562341
##  [85] -1.51503473 -0.24121274  0.91556687  0.64537308  0.48311177 -1.14217407
##  [91] -1.12039092 -1.27141453  0.91636167  2.04091439  2.13232979  2.23257264
##  [97]  0.25301429  1.21071226  1.29939237  3.92904462  4.07112121  3.78513073
## [103]  2.83160983  1.41191959  0.28488816 -0.04006883 -1.28812485 -0.74220308
## [109] -0.74424287 -0.32976863 -0.31752860 -0.98342470 -2.04217397 -1.20184647
## [115] -1.31314616  0.45270778 -0.93468943 -0.20680752 -0.29613748  0.15497575
## [121]  0.22025744 -0.73310547  1.30806278  1.61203256  4.42693491  3.79591780
## [127]  3.27848542  0.68061022 -0.62425847 -1.11211846  0.04164014  0.59240357
## [133] -0.15810424  0.39101368 -1.92189820 -1.50741039 -2.59060462 -3.89098912
## [139] -2.51252738 -3.45825773 -2.26278511 -0.93523383  0.07413764  0.83334886
## [145]  1.28389670  1.34833602  3.06177019  2.98115137  3.71727357  3.17046413
## [151]  2.39423349  1.98646516  2.92352912  1.69753466  2.18824295  2.31910758
## [157]  1.98048956  1.12411345 -0.47375475 -1.38212484 -2.31108442 -2.26562282
## [163] -2.62211380 -2.26938378 -1.57393069 -0.56321701  1.57589801  1.65267412
## [169]  1.80012273  2.53204975  3.72627716  3.97712776  3.44105725  0.58660225
## [175]  1.46428641 -0.51695507 -0.57765858  1.69949100  1.51248377  2.98314953
## [181] -0.81043866 -1.02122299 -1.37591544 -0.14779506  1.31440815  3.22462748
## [187]  4.38519006  3.98666624  4.07252161  2.61160764  1.92537895 -1.70502573
## [193] -2.72222986 -3.24361938 -0.27688538  0.87342985  2.50264542  1.00860632
## [199]  1.15325179 -1.81437043 -0.92501023 -1.18146222 -0.02037563  0.94652009
## [205]  1.17246770  2.08111275  3.60870710  4.52620181  4.56792960  2.75523948
## [211]  2.28308227  0.79090755  2.43630393  0.12650863  0.38802680 -0.48922578
## [217] -0.39939179 -0.71118176 -1.07369267 -0.53512569  0.48185240  1.52990415
## [223]  3.93599432  4.75299655  5.28489601  3.75245965  5.76106696  5.08023491
## [229]  5.03046078  3.85049062  2.27094879  1.61300623  0.02267186 -0.08744134
## [235] -0.23338993 -1.01395405 -4.02632785 -4.41061552 -5.02289664 -2.94041531
## [241] -2.16023161 -0.87458164 -1.76626866 -0.53794493 -0.27753067  0.71955739
## [247]  2.19354067  2.33905070  2.84874980  2.50865574  2.52684453  3.16087589
## [253]  3.22420516  3.72442687  1.90727460  1.27139490  1.66409882  0.23091397
## [259]  1.10296539  0.37155340  1.69901525  1.20826458  1.54849208 -0.89323198
## [265] -0.40844829 -1.97195019 -1.36977976 -2.76244287 -1.88853615 -1.38886217
## [271] -0.87915921  1.38576118  1.73484421  3.45643730  4.90637915  3.88230417
## [277]  4.70024354  4.04594276  3.83665310  3.63604751  1.69745094  1.83280517
## [283]  0.13589632  1.24990445 -0.25440835  0.60581161 -0.95359799 -0.74837042
## [289] -2.72398269 -2.15183291 -1.51561139 -0.53368698 -1.67162994 -2.15962923
## [295] -1.06604857  1.13495225  0.89677762  0.92454452  0.14354987  0.49726828

B. Menggunakan arma.sim

# Kak ini aku ga bisa pake fungsi arma.sim soalnya error terus, udah dicari caranya tapi ttp gabisa :(
arma22 = arima.sim(model = list(ar = c(0.5, 0.2), ma = c(0.4, 0.6)), n = 300)
arma22
## Time Series:
## Start = 1 
## End = 300 
## Frequency = 1 
##   [1] -2.0296272586  0.1804874357 -1.0857429326  0.2019685297  0.5101006237
##   [6]  0.3116647978  1.1440157679  0.4568971792 -0.3804875233 -0.8758133113
##  [11]  0.3166261152  0.2548874061  0.2592079202 -0.3290331722 -0.2948120396
##  [16]  0.8417548499  2.0860897066  2.3426969416  3.4797265438  1.9702862497
##  [21] -0.2703838028 -1.6091794075 -2.9699033669 -4.6121759676 -3.5735246545
##  [26] -4.6576056483 -3.2455887429 -4.7021051669 -3.2231197169 -1.3940059863
##  [31] -1.1346987187 -0.1752041013  1.0623014400  2.1418761113  4.7392121372
##  [36]  4.1182608009  4.0004548088  2.2502034531  3.0645576995  0.9645314951
##  [41]  1.7489003118  0.3724604884  2.9537132225  1.8162605804  1.0974763535
##  [46]  0.1760865572 -0.5446303408 -0.9525033432 -0.8123258962 -1.3227469686
##  [51] -1.5334325506 -0.9672480418 -1.3288936550 -2.5250400524 -5.1130294931
##  [56] -5.8037895789 -4.2935914351 -2.2360988083  0.4460497638  1.7472096231
##  [61]  2.4006131137  0.7584947290  0.6515731377  1.2527039433 -1.8771638270
##  [66] -1.8694819688 -2.5578881435 -1.1519209603  0.5748330869  1.1471366303
##  [71]  1.8838444926  1.6757856446  0.6273297035 -0.9358028910 -1.3469021544
##  [76] -2.0036326762 -2.3174267020 -1.7545802003 -1.5599728217  0.6442232795
##  [81] -0.4340053617 -0.1765772798 -1.1300535322 -2.3487839887 -2.2931928545
##  [86] -3.2830807993 -4.7019099638 -4.5753666098 -5.1642557266 -2.7481221530
##  [91] -2.8782203654 -0.9930444704 -1.0689737305 -1.5783972995 -1.0380159333
##  [96] -1.5332320899 -0.6261053110  0.0411088954  0.3721474367  2.2198607384
## [101]  2.0023547146  1.1884673403  1.3043018409 -0.7887107383 -2.0964309112
## [106] -3.5171926149 -4.3978707535 -4.2937125479 -2.1094795649  0.0003174271
## [111]  1.9226494154  0.9593493745  0.8134718138  0.3306846828  0.3997456277
## [116]  0.6752169718 -0.5407546124 -1.6978244943 -0.6312219023 -0.5972690490
## [121]  0.1183319718  0.2620479526  2.1022412464  2.4863522906  4.4575844054
## [126]  4.8757690067  4.3160857500  4.5533945371  2.5494245996  0.9087801371
## [131] -1.2175736136 -1.9406110437 -0.1972454851  0.2476564511  0.4017020994
## [136]  0.2225073455  0.5000164875 -0.5832769633 -1.3456109790 -3.9300614982
## [141] -4.9131646646 -5.8028221737 -5.2926716626 -3.0460358047 -1.3040226410
## [146]  0.2132688421 -0.0784369871 -0.0996436572  0.1260353647 -0.2660236350
## [151]  1.0782194035  1.7045666001  0.9758460554  0.2737953256  0.5401383054
## [156] -1.3278429554 -0.0870286339 -0.9200321168  3.0637048543  0.0366253987
## [161]  0.6159264510 -0.9848095514  1.0702410108  2.2519934840  1.2521472479
## [166]  3.2483253660  0.1560601148  0.2554054546 -1.3837918100  0.8997062858
## [171]  1.5437618975  3.2200970376  4.2428268660  4.8796814776  3.4944267802
## [176]  3.5338487343  1.9056374923  3.8243441222  2.6973660425  1.5586316888
## [181]  1.0537138077  0.4735564378  0.8667967201 -0.3227890170 -1.2601457680
## [186] -1.6767524636 -0.5606943256 -0.5724867409 -0.7927487057 -3.7823291437
## [191] -3.1600153700 -3.3339550694 -0.5223037166  1.3188603092  1.7841169179
## [196]  3.2771554059  2.4302864848  1.9737979026  0.3549837497 -0.5198143292
## [201] -0.6091253699 -0.5530998375 -0.0719700978  0.1162479295  0.9584330444
## [206]  0.6344896787  2.4637658099  2.2867046454  1.5988556633  0.7653209481
## [211]  0.3915332251 -0.0218611922  0.5574787959  0.6001278409  2.0957927366
## [216]  1.2982546155  1.5728132382  0.0805951955 -1.0094781239 -3.1290589551
## [221] -2.9867638935 -2.5487990772 -0.8746506343 -1.7204755510 -2.3373479869
## [226] -3.9397901303 -4.2603045521 -3.7080736007 -2.4567380560 -2.4451043371
## [231] -4.5475696207 -3.4437405213 -3.3531781238 -2.2477998694 -2.7793743188
## [236] -2.9892252870 -2.7065742281 -1.3646835008  0.5205827432  0.1284297696
## [241]  0.9535579764  1.4436000747  0.7192735976  0.8655621589 -1.8247428875
## [246] -1.2940820209 -2.6010932672 -2.5683240349 -3.3390482543 -2.6056391336
## [251] -4.4232833523 -3.7565659797 -5.2443430811 -4.9963973684 -4.0655108800
## [256] -3.0676982101 -2.0284891531 -0.9220225427 -1.3180193115 -2.7850434151
## [261] -1.6722862864 -2.3760548989 -1.2871979057 -1.2457433091 -0.2704251019
## [266]  0.4426094002  1.7244792000  1.6234544126  1.2271504803  0.4637832128
## [271]  0.8774865319 -0.1688721412 -0.7085067912 -0.9655544239 -0.4587798338
## [276] -1.6805074767 -0.4562603842 -1.2530770377 -0.4234566530  0.5792636344
## [281]  2.0183639459  1.2335658487  2.4607872362  0.5612596789  1.2593135541
## [286]  0.8965377884  1.1050964502 -0.3891819897 -0.9852126937 -0.1110588970
## [291]  0.2322458578  0.2510026152 -0.7146316233 -0.0134150381  0.2259188584
## [296] -0.0139370725 -0.1067440762  0.0047052158  1.9459829310  1.1392060539

Plot simulasi ARMA(2,2)

# Plot simulasi 
ts.plot(arma22, 
        main="Simulasi ARMA(2,2)", 
        ylab="Yt")

Plot ACF (Autocorrelation Function)

# Plot ACF 
acf(arma22, main="ACF ARMA(2,2)") 

Plot ACF dari ARMA(2,2) yang sudah dibangkitkan menunjukkan adanya tails off.

Hal ini menandakan adanya ciri khas dari komponen AR

Plot PACF (Partial Autocorrelation Function)

# Plot PACF 
pacf(arma22, main="PACF ARMA(2,2)")

Plot PACF dari ARMA(2,2) yang sudah dibangkitkan menunjukkan adanya cut off di lag 2.

Hal ini menandakan adanya ciri khas dari komponen MA

Plot EACF (Extended Autocorrelation Function)

# Plot EACF
library(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  x 
## 1 x x o o o o o o o o o  o  o  o 
## 2 x x x x o o o o o o o  o  o  o 
## 3 x x o x o 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 o o o o o o o  o  o  o 
## 6 x x x x o x o o o o o  o  o  o 
## 7 x x o x x x x o o o o  o  o  o

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

Scatterplot

# Yt
yt_arma22 = arma22[-c(1:3)]

# Yt-1
yt_1_arma22 = arma22[-c((n-2):n)]

# Yt-2
yt_2_arma22 = arma22[-c((n-1):n)]
yt_2_arma22 = yt_2_arma22[-1]       

# Yt-3
yt_3_arma22 = arma22[-n]          
yt_3_arma22 = yt_3_arma22[-c(1:2)]  
# Perbandingan Yt dengan Yt-1
yt_arma22
##   [1]  0.2019685297  0.5101006237  0.3116647978  1.1440157679  0.4568971792
##   [6] -0.3804875233 -0.8758133113  0.3166261152  0.2548874061  0.2592079202
##  [11] -0.3290331722 -0.2948120396  0.8417548499  2.0860897066  2.3426969416
##  [16]  3.4797265438  1.9702862497 -0.2703838028 -1.6091794075 -2.9699033669
##  [21] -4.6121759676 -3.5735246545 -4.6576056483 -3.2455887429 -4.7021051669
##  [26] -3.2231197169 -1.3940059863 -1.1346987187 -0.1752041013  1.0623014400
##  [31]  2.1418761113  4.7392121372  4.1182608009  4.0004548088  2.2502034531
##  [36]  3.0645576995  0.9645314951  1.7489003118  0.3724604884  2.9537132225
##  [41]  1.8162605804  1.0974763535  0.1760865572 -0.5446303408 -0.9525033432
##  [46] -0.8123258962 -1.3227469686 -1.5334325506 -0.9672480418 -1.3288936550
##  [51] -2.5250400524 -5.1130294931 -5.8037895789 -4.2935914351 -2.2360988083
##  [56]  0.4460497638  1.7472096231  2.4006131137  0.7584947290  0.6515731377
##  [61]  1.2527039433 -1.8771638270 -1.8694819688 -2.5578881435 -1.1519209603
##  [66]  0.5748330869  1.1471366303  1.8838444926  1.6757856446  0.6273297035
##  [71] -0.9358028910 -1.3469021544 -2.0036326762 -2.3174267020 -1.7545802003
##  [76] -1.5599728217  0.6442232795 -0.4340053617 -0.1765772798 -1.1300535322
##  [81] -2.3487839887 -2.2931928545 -3.2830807993 -4.7019099638 -4.5753666098
##  [86] -5.1642557266 -2.7481221530 -2.8782203654 -0.9930444704 -1.0689737305
##  [91] -1.5783972995 -1.0380159333 -1.5332320899 -0.6261053110  0.0411088954
##  [96]  0.3721474367  2.2198607384  2.0023547146  1.1884673403  1.3043018409
## [101] -0.7887107383 -2.0964309112 -3.5171926149 -4.3978707535 -4.2937125479
## [106] -2.1094795649  0.0003174271  1.9226494154  0.9593493745  0.8134718138
## [111]  0.3306846828  0.3997456277  0.6752169718 -0.5407546124 -1.6978244943
## [116] -0.6312219023 -0.5972690490  0.1183319718  0.2620479526  2.1022412464
## [121]  2.4863522906  4.4575844054  4.8757690067  4.3160857500  4.5533945371
## [126]  2.5494245996  0.9087801371 -1.2175736136 -1.9406110437 -0.1972454851
## [131]  0.2476564511  0.4017020994  0.2225073455  0.5000164875 -0.5832769633
## [136] -1.3456109790 -3.9300614982 -4.9131646646 -5.8028221737 -5.2926716626
## [141] -3.0460358047 -1.3040226410  0.2132688421 -0.0784369871 -0.0996436572
## [146]  0.1260353647 -0.2660236350  1.0782194035  1.7045666001  0.9758460554
## [151]  0.2737953256  0.5401383054 -1.3278429554 -0.0870286339 -0.9200321168
## [156]  3.0637048543  0.0366253987  0.6159264510 -0.9848095514  1.0702410108
## [161]  2.2519934840  1.2521472479  3.2483253660  0.1560601148  0.2554054546
## [166] -1.3837918100  0.8997062858  1.5437618975  3.2200970376  4.2428268660
## [171]  4.8796814776  3.4944267802  3.5338487343  1.9056374923  3.8243441222
## [176]  2.6973660425  1.5586316888  1.0537138077  0.4735564378  0.8667967201
## [181] -0.3227890170 -1.2601457680 -1.6767524636 -0.5606943256 -0.5724867409
## [186] -0.7927487057 -3.7823291437 -3.1600153700 -3.3339550694 -0.5223037166
## [191]  1.3188603092  1.7841169179  3.2771554059  2.4302864848  1.9737979026
## [196]  0.3549837497 -0.5198143292 -0.6091253699 -0.5530998375 -0.0719700978
## [201]  0.1162479295  0.9584330444  0.6344896787  2.4637658099  2.2867046454
## [206]  1.5988556633  0.7653209481  0.3915332251 -0.0218611922  0.5574787959
## [211]  0.6001278409  2.0957927366  1.2982546155  1.5728132382  0.0805951955
## [216] -1.0094781239 -3.1290589551 -2.9867638935 -2.5487990772 -0.8746506343
## [221] -1.7204755510 -2.3373479869 -3.9397901303 -4.2603045521 -3.7080736007
## [226] -2.4567380560 -2.4451043371 -4.5475696207 -3.4437405213 -3.3531781238
## [231] -2.2477998694 -2.7793743188 -2.9892252870 -2.7065742281 -1.3646835008
## [236]  0.5205827432  0.1284297696  0.9535579764  1.4436000747  0.7192735976
## [241]  0.8655621589 -1.8247428875 -1.2940820209 -2.6010932672 -2.5683240349
## [246] -3.3390482543 -2.6056391336 -4.4232833523 -3.7565659797 -5.2443430811
## [251] -4.9963973684 -4.0655108800 -3.0676982101 -2.0284891531 -0.9220225427
## [256] -1.3180193115 -2.7850434151 -1.6722862864 -2.3760548989 -1.2871979057
## [261] -1.2457433091 -0.2704251019  0.4426094002  1.7244792000  1.6234544126
## [266]  1.2271504803  0.4637832128  0.8774865319 -0.1688721412 -0.7085067912
## [271] -0.9655544239 -0.4587798338 -1.6805074767 -0.4562603842 -1.2530770377
## [276] -0.4234566530  0.5792636344  2.0183639459  1.2335658487  2.4607872362
## [281]  0.5612596789  1.2593135541  0.8965377884  1.1050964502 -0.3891819897
## [286] -0.9852126937 -0.1110588970  0.2322458578  0.2510026152 -0.7146316233
## [291] -0.0134150381  0.2259188584 -0.0139370725 -0.1067440762  0.0047052158
## [296]  1.9459829310  1.1392060539
yt_1_arma22
##   [1] -2.0296272586  0.1804874357 -1.0857429326  0.2019685297  0.5101006237
##   [6]  0.3116647978  1.1440157679  0.4568971792 -0.3804875233 -0.8758133113
##  [11]  0.3166261152  0.2548874061  0.2592079202 -0.3290331722 -0.2948120396
##  [16]  0.8417548499  2.0860897066  2.3426969416  3.4797265438  1.9702862497
##  [21] -0.2703838028 -1.6091794075 -2.9699033669 -4.6121759676 -3.5735246545
##  [26] -4.6576056483 -3.2455887429 -4.7021051669 -3.2231197169 -1.3940059863
##  [31] -1.1346987187 -0.1752041013  1.0623014400  2.1418761113  4.7392121372
##  [36]  4.1182608009  4.0004548088  2.2502034531  3.0645576995  0.9645314951
##  [41]  1.7489003118  0.3724604884  2.9537132225  1.8162605804  1.0974763535
##  [46]  0.1760865572 -0.5446303408 -0.9525033432 -0.8123258962 -1.3227469686
##  [51] -1.5334325506 -0.9672480418 -1.3288936550 -2.5250400524 -5.1130294931
##  [56] -5.8037895789 -4.2935914351 -2.2360988083  0.4460497638  1.7472096231
##  [61]  2.4006131137  0.7584947290  0.6515731377  1.2527039433 -1.8771638270
##  [66] -1.8694819688 -2.5578881435 -1.1519209603  0.5748330869  1.1471366303
##  [71]  1.8838444926  1.6757856446  0.6273297035 -0.9358028910 -1.3469021544
##  [76] -2.0036326762 -2.3174267020 -1.7545802003 -1.5599728217  0.6442232795
##  [81] -0.4340053617 -0.1765772798 -1.1300535322 -2.3487839887 -2.2931928545
##  [86] -3.2830807993 -4.7019099638 -4.5753666098 -5.1642557266 -2.7481221530
##  [91] -2.8782203654 -0.9930444704 -1.0689737305 -1.5783972995 -1.0380159333
##  [96] -1.5332320899 -0.6261053110  0.0411088954  0.3721474367  2.2198607384
## [101]  2.0023547146  1.1884673403  1.3043018409 -0.7887107383 -2.0964309112
## [106] -3.5171926149 -4.3978707535 -4.2937125479 -2.1094795649  0.0003174271
## [111]  1.9226494154  0.9593493745  0.8134718138  0.3306846828  0.3997456277
## [116]  0.6752169718 -0.5407546124 -1.6978244943 -0.6312219023 -0.5972690490
## [121]  0.1183319718  0.2620479526  2.1022412464  2.4863522906  4.4575844054
## [126]  4.8757690067  4.3160857500  4.5533945371  2.5494245996  0.9087801371
## [131] -1.2175736136 -1.9406110437 -0.1972454851  0.2476564511  0.4017020994
## [136]  0.2225073455  0.5000164875 -0.5832769633 -1.3456109790 -3.9300614982
## [141] -4.9131646646 -5.8028221737 -5.2926716626 -3.0460358047 -1.3040226410
## [146]  0.2132688421 -0.0784369871 -0.0996436572  0.1260353647 -0.2660236350
## [151]  1.0782194035  1.7045666001  0.9758460554  0.2737953256  0.5401383054
## [156] -1.3278429554 -0.0870286339 -0.9200321168  3.0637048543  0.0366253987
## [161]  0.6159264510 -0.9848095514  1.0702410108  2.2519934840  1.2521472479
## [166]  3.2483253660  0.1560601148  0.2554054546 -1.3837918100  0.8997062858
## [171]  1.5437618975  3.2200970376  4.2428268660  4.8796814776  3.4944267802
## [176]  3.5338487343  1.9056374923  3.8243441222  2.6973660425  1.5586316888
## [181]  1.0537138077  0.4735564378  0.8667967201 -0.3227890170 -1.2601457680
## [186] -1.6767524636 -0.5606943256 -0.5724867409 -0.7927487057 -3.7823291437
## [191] -3.1600153700 -3.3339550694 -0.5223037166  1.3188603092  1.7841169179
## [196]  3.2771554059  2.4302864848  1.9737979026  0.3549837497 -0.5198143292
## [201] -0.6091253699 -0.5530998375 -0.0719700978  0.1162479295  0.9584330444
## [206]  0.6344896787  2.4637658099  2.2867046454  1.5988556633  0.7653209481
## [211]  0.3915332251 -0.0218611922  0.5574787959  0.6001278409  2.0957927366
## [216]  1.2982546155  1.5728132382  0.0805951955 -1.0094781239 -3.1290589551
## [221] -2.9867638935 -2.5487990772 -0.8746506343 -1.7204755510 -2.3373479869
## [226] -3.9397901303 -4.2603045521 -3.7080736007 -2.4567380560 -2.4451043371
## [231] -4.5475696207 -3.4437405213 -3.3531781238 -2.2477998694 -2.7793743188
## [236] -2.9892252870 -2.7065742281 -1.3646835008  0.5205827432  0.1284297696
## [241]  0.9535579764  1.4436000747  0.7192735976  0.8655621589 -1.8247428875
## [246] -1.2940820209 -2.6010932672 -2.5683240349 -3.3390482543 -2.6056391336
## [251] -4.4232833523 -3.7565659797 -5.2443430811 -4.9963973684 -4.0655108800
## [256] -3.0676982101 -2.0284891531 -0.9220225427 -1.3180193115 -2.7850434151
## [261] -1.6722862864 -2.3760548989 -1.2871979057 -1.2457433091 -0.2704251019
## [266]  0.4426094002  1.7244792000  1.6234544126  1.2271504803  0.4637832128
## [271]  0.8774865319 -0.1688721412 -0.7085067912 -0.9655544239 -0.4587798338
## [276] -1.6805074767 -0.4562603842 -1.2530770377 -0.4234566530  0.5792636344
## [281]  2.0183639459  1.2335658487  2.4607872362  0.5612596789  1.2593135541
## [286]  0.8965377884  1.1050964502 -0.3891819897 -0.9852126937 -0.1110588970
## [291]  0.2322458578  0.2510026152 -0.7146316233 -0.0134150381  0.2259188584
## [296] -0.0139370725 -0.1067440762
# Perbandingan Yt dengan Yt-2
yt_arma22
##   [1]  0.2019685297  0.5101006237  0.3116647978  1.1440157679  0.4568971792
##   [6] -0.3804875233 -0.8758133113  0.3166261152  0.2548874061  0.2592079202
##  [11] -0.3290331722 -0.2948120396  0.8417548499  2.0860897066  2.3426969416
##  [16]  3.4797265438  1.9702862497 -0.2703838028 -1.6091794075 -2.9699033669
##  [21] -4.6121759676 -3.5735246545 -4.6576056483 -3.2455887429 -4.7021051669
##  [26] -3.2231197169 -1.3940059863 -1.1346987187 -0.1752041013  1.0623014400
##  [31]  2.1418761113  4.7392121372  4.1182608009  4.0004548088  2.2502034531
##  [36]  3.0645576995  0.9645314951  1.7489003118  0.3724604884  2.9537132225
##  [41]  1.8162605804  1.0974763535  0.1760865572 -0.5446303408 -0.9525033432
##  [46] -0.8123258962 -1.3227469686 -1.5334325506 -0.9672480418 -1.3288936550
##  [51] -2.5250400524 -5.1130294931 -5.8037895789 -4.2935914351 -2.2360988083
##  [56]  0.4460497638  1.7472096231  2.4006131137  0.7584947290  0.6515731377
##  [61]  1.2527039433 -1.8771638270 -1.8694819688 -2.5578881435 -1.1519209603
##  [66]  0.5748330869  1.1471366303  1.8838444926  1.6757856446  0.6273297035
##  [71] -0.9358028910 -1.3469021544 -2.0036326762 -2.3174267020 -1.7545802003
##  [76] -1.5599728217  0.6442232795 -0.4340053617 -0.1765772798 -1.1300535322
##  [81] -2.3487839887 -2.2931928545 -3.2830807993 -4.7019099638 -4.5753666098
##  [86] -5.1642557266 -2.7481221530 -2.8782203654 -0.9930444704 -1.0689737305
##  [91] -1.5783972995 -1.0380159333 -1.5332320899 -0.6261053110  0.0411088954
##  [96]  0.3721474367  2.2198607384  2.0023547146  1.1884673403  1.3043018409
## [101] -0.7887107383 -2.0964309112 -3.5171926149 -4.3978707535 -4.2937125479
## [106] -2.1094795649  0.0003174271  1.9226494154  0.9593493745  0.8134718138
## [111]  0.3306846828  0.3997456277  0.6752169718 -0.5407546124 -1.6978244943
## [116] -0.6312219023 -0.5972690490  0.1183319718  0.2620479526  2.1022412464
## [121]  2.4863522906  4.4575844054  4.8757690067  4.3160857500  4.5533945371
## [126]  2.5494245996  0.9087801371 -1.2175736136 -1.9406110437 -0.1972454851
## [131]  0.2476564511  0.4017020994  0.2225073455  0.5000164875 -0.5832769633
## [136] -1.3456109790 -3.9300614982 -4.9131646646 -5.8028221737 -5.2926716626
## [141] -3.0460358047 -1.3040226410  0.2132688421 -0.0784369871 -0.0996436572
## [146]  0.1260353647 -0.2660236350  1.0782194035  1.7045666001  0.9758460554
## [151]  0.2737953256  0.5401383054 -1.3278429554 -0.0870286339 -0.9200321168
## [156]  3.0637048543  0.0366253987  0.6159264510 -0.9848095514  1.0702410108
## [161]  2.2519934840  1.2521472479  3.2483253660  0.1560601148  0.2554054546
## [166] -1.3837918100  0.8997062858  1.5437618975  3.2200970376  4.2428268660
## [171]  4.8796814776  3.4944267802  3.5338487343  1.9056374923  3.8243441222
## [176]  2.6973660425  1.5586316888  1.0537138077  0.4735564378  0.8667967201
## [181] -0.3227890170 -1.2601457680 -1.6767524636 -0.5606943256 -0.5724867409
## [186] -0.7927487057 -3.7823291437 -3.1600153700 -3.3339550694 -0.5223037166
## [191]  1.3188603092  1.7841169179  3.2771554059  2.4302864848  1.9737979026
## [196]  0.3549837497 -0.5198143292 -0.6091253699 -0.5530998375 -0.0719700978
## [201]  0.1162479295  0.9584330444  0.6344896787  2.4637658099  2.2867046454
## [206]  1.5988556633  0.7653209481  0.3915332251 -0.0218611922  0.5574787959
## [211]  0.6001278409  2.0957927366  1.2982546155  1.5728132382  0.0805951955
## [216] -1.0094781239 -3.1290589551 -2.9867638935 -2.5487990772 -0.8746506343
## [221] -1.7204755510 -2.3373479869 -3.9397901303 -4.2603045521 -3.7080736007
## [226] -2.4567380560 -2.4451043371 -4.5475696207 -3.4437405213 -3.3531781238
## [231] -2.2477998694 -2.7793743188 -2.9892252870 -2.7065742281 -1.3646835008
## [236]  0.5205827432  0.1284297696  0.9535579764  1.4436000747  0.7192735976
## [241]  0.8655621589 -1.8247428875 -1.2940820209 -2.6010932672 -2.5683240349
## [246] -3.3390482543 -2.6056391336 -4.4232833523 -3.7565659797 -5.2443430811
## [251] -4.9963973684 -4.0655108800 -3.0676982101 -2.0284891531 -0.9220225427
## [256] -1.3180193115 -2.7850434151 -1.6722862864 -2.3760548989 -1.2871979057
## [261] -1.2457433091 -0.2704251019  0.4426094002  1.7244792000  1.6234544126
## [266]  1.2271504803  0.4637832128  0.8774865319 -0.1688721412 -0.7085067912
## [271] -0.9655544239 -0.4587798338 -1.6805074767 -0.4562603842 -1.2530770377
## [276] -0.4234566530  0.5792636344  2.0183639459  1.2335658487  2.4607872362
## [281]  0.5612596789  1.2593135541  0.8965377884  1.1050964502 -0.3891819897
## [286] -0.9852126937 -0.1110588970  0.2322458578  0.2510026152 -0.7146316233
## [291] -0.0134150381  0.2259188584 -0.0139370725 -0.1067440762  0.0047052158
## [296]  1.9459829310  1.1392060539
yt_2_arma22
##   [1]  0.1804874357 -1.0857429326  0.2019685297  0.5101006237  0.3116647978
##   [6]  1.1440157679  0.4568971792 -0.3804875233 -0.8758133113  0.3166261152
##  [11]  0.2548874061  0.2592079202 -0.3290331722 -0.2948120396  0.8417548499
##  [16]  2.0860897066  2.3426969416  3.4797265438  1.9702862497 -0.2703838028
##  [21] -1.6091794075 -2.9699033669 -4.6121759676 -3.5735246545 -4.6576056483
##  [26] -3.2455887429 -4.7021051669 -3.2231197169 -1.3940059863 -1.1346987187
##  [31] -0.1752041013  1.0623014400  2.1418761113  4.7392121372  4.1182608009
##  [36]  4.0004548088  2.2502034531  3.0645576995  0.9645314951  1.7489003118
##  [41]  0.3724604884  2.9537132225  1.8162605804  1.0974763535  0.1760865572
##  [46] -0.5446303408 -0.9525033432 -0.8123258962 -1.3227469686 -1.5334325506
##  [51] -0.9672480418 -1.3288936550 -2.5250400524 -5.1130294931 -5.8037895789
##  [56] -4.2935914351 -2.2360988083  0.4460497638  1.7472096231  2.4006131137
##  [61]  0.7584947290  0.6515731377  1.2527039433 -1.8771638270 -1.8694819688
##  [66] -2.5578881435 -1.1519209603  0.5748330869  1.1471366303  1.8838444926
##  [71]  1.6757856446  0.6273297035 -0.9358028910 -1.3469021544 -2.0036326762
##  [76] -2.3174267020 -1.7545802003 -1.5599728217  0.6442232795 -0.4340053617
##  [81] -0.1765772798 -1.1300535322 -2.3487839887 -2.2931928545 -3.2830807993
##  [86] -4.7019099638 -4.5753666098 -5.1642557266 -2.7481221530 -2.8782203654
##  [91] -0.9930444704 -1.0689737305 -1.5783972995 -1.0380159333 -1.5332320899
##  [96] -0.6261053110  0.0411088954  0.3721474367  2.2198607384  2.0023547146
## [101]  1.1884673403  1.3043018409 -0.7887107383 -2.0964309112 -3.5171926149
## [106] -4.3978707535 -4.2937125479 -2.1094795649  0.0003174271  1.9226494154
## [111]  0.9593493745  0.8134718138  0.3306846828  0.3997456277  0.6752169718
## [116] -0.5407546124 -1.6978244943 -0.6312219023 -0.5972690490  0.1183319718
## [121]  0.2620479526  2.1022412464  2.4863522906  4.4575844054  4.8757690067
## [126]  4.3160857500  4.5533945371  2.5494245996  0.9087801371 -1.2175736136
## [131] -1.9406110437 -0.1972454851  0.2476564511  0.4017020994  0.2225073455
## [136]  0.5000164875 -0.5832769633 -1.3456109790 -3.9300614982 -4.9131646646
## [141] -5.8028221737 -5.2926716626 -3.0460358047 -1.3040226410  0.2132688421
## [146] -0.0784369871 -0.0996436572  0.1260353647 -0.2660236350  1.0782194035
## [151]  1.7045666001  0.9758460554  0.2737953256  0.5401383054 -1.3278429554
## [156] -0.0870286339 -0.9200321168  3.0637048543  0.0366253987  0.6159264510
## [161] -0.9848095514  1.0702410108  2.2519934840  1.2521472479  3.2483253660
## [166]  0.1560601148  0.2554054546 -1.3837918100  0.8997062858  1.5437618975
## [171]  3.2200970376  4.2428268660  4.8796814776  3.4944267802  3.5338487343
## [176]  1.9056374923  3.8243441222  2.6973660425  1.5586316888  1.0537138077
## [181]  0.4735564378  0.8667967201 -0.3227890170 -1.2601457680 -1.6767524636
## [186] -0.5606943256 -0.5724867409 -0.7927487057 -3.7823291437 -3.1600153700
## [191] -3.3339550694 -0.5223037166  1.3188603092  1.7841169179  3.2771554059
## [196]  2.4302864848  1.9737979026  0.3549837497 -0.5198143292 -0.6091253699
## [201] -0.5530998375 -0.0719700978  0.1162479295  0.9584330444  0.6344896787
## [206]  2.4637658099  2.2867046454  1.5988556633  0.7653209481  0.3915332251
## [211] -0.0218611922  0.5574787959  0.6001278409  2.0957927366  1.2982546155
## [216]  1.5728132382  0.0805951955 -1.0094781239 -3.1290589551 -2.9867638935
## [221] -2.5487990772 -0.8746506343 -1.7204755510 -2.3373479869 -3.9397901303
## [226] -4.2603045521 -3.7080736007 -2.4567380560 -2.4451043371 -4.5475696207
## [231] -3.4437405213 -3.3531781238 -2.2477998694 -2.7793743188 -2.9892252870
## [236] -2.7065742281 -1.3646835008  0.5205827432  0.1284297696  0.9535579764
## [241]  1.4436000747  0.7192735976  0.8655621589 -1.8247428875 -1.2940820209
## [246] -2.6010932672 -2.5683240349 -3.3390482543 -2.6056391336 -4.4232833523
## [251] -3.7565659797 -5.2443430811 -4.9963973684 -4.0655108800 -3.0676982101
## [256] -2.0284891531 -0.9220225427 -1.3180193115 -2.7850434151 -1.6722862864
## [261] -2.3760548989 -1.2871979057 -1.2457433091 -0.2704251019  0.4426094002
## [266]  1.7244792000  1.6234544126  1.2271504803  0.4637832128  0.8774865319
## [271] -0.1688721412 -0.7085067912 -0.9655544239 -0.4587798338 -1.6805074767
## [276] -0.4562603842 -1.2530770377 -0.4234566530  0.5792636344  2.0183639459
## [281]  1.2335658487  2.4607872362  0.5612596789  1.2593135541  0.8965377884
## [286]  1.1050964502 -0.3891819897 -0.9852126937 -0.1110588970  0.2322458578
## [291]  0.2510026152 -0.7146316233 -0.0134150381  0.2259188584 -0.0139370725
## [296] -0.1067440762  0.0047052158
# Perbandingan Yt dengan Yt-3
yt_arma22
##   [1]  0.2019685297  0.5101006237  0.3116647978  1.1440157679  0.4568971792
##   [6] -0.3804875233 -0.8758133113  0.3166261152  0.2548874061  0.2592079202
##  [11] -0.3290331722 -0.2948120396  0.8417548499  2.0860897066  2.3426969416
##  [16]  3.4797265438  1.9702862497 -0.2703838028 -1.6091794075 -2.9699033669
##  [21] -4.6121759676 -3.5735246545 -4.6576056483 -3.2455887429 -4.7021051669
##  [26] -3.2231197169 -1.3940059863 -1.1346987187 -0.1752041013  1.0623014400
##  [31]  2.1418761113  4.7392121372  4.1182608009  4.0004548088  2.2502034531
##  [36]  3.0645576995  0.9645314951  1.7489003118  0.3724604884  2.9537132225
##  [41]  1.8162605804  1.0974763535  0.1760865572 -0.5446303408 -0.9525033432
##  [46] -0.8123258962 -1.3227469686 -1.5334325506 -0.9672480418 -1.3288936550
##  [51] -2.5250400524 -5.1130294931 -5.8037895789 -4.2935914351 -2.2360988083
##  [56]  0.4460497638  1.7472096231  2.4006131137  0.7584947290  0.6515731377
##  [61]  1.2527039433 -1.8771638270 -1.8694819688 -2.5578881435 -1.1519209603
##  [66]  0.5748330869  1.1471366303  1.8838444926  1.6757856446  0.6273297035
##  [71] -0.9358028910 -1.3469021544 -2.0036326762 -2.3174267020 -1.7545802003
##  [76] -1.5599728217  0.6442232795 -0.4340053617 -0.1765772798 -1.1300535322
##  [81] -2.3487839887 -2.2931928545 -3.2830807993 -4.7019099638 -4.5753666098
##  [86] -5.1642557266 -2.7481221530 -2.8782203654 -0.9930444704 -1.0689737305
##  [91] -1.5783972995 -1.0380159333 -1.5332320899 -0.6261053110  0.0411088954
##  [96]  0.3721474367  2.2198607384  2.0023547146  1.1884673403  1.3043018409
## [101] -0.7887107383 -2.0964309112 -3.5171926149 -4.3978707535 -4.2937125479
## [106] -2.1094795649  0.0003174271  1.9226494154  0.9593493745  0.8134718138
## [111]  0.3306846828  0.3997456277  0.6752169718 -0.5407546124 -1.6978244943
## [116] -0.6312219023 -0.5972690490  0.1183319718  0.2620479526  2.1022412464
## [121]  2.4863522906  4.4575844054  4.8757690067  4.3160857500  4.5533945371
## [126]  2.5494245996  0.9087801371 -1.2175736136 -1.9406110437 -0.1972454851
## [131]  0.2476564511  0.4017020994  0.2225073455  0.5000164875 -0.5832769633
## [136] -1.3456109790 -3.9300614982 -4.9131646646 -5.8028221737 -5.2926716626
## [141] -3.0460358047 -1.3040226410  0.2132688421 -0.0784369871 -0.0996436572
## [146]  0.1260353647 -0.2660236350  1.0782194035  1.7045666001  0.9758460554
## [151]  0.2737953256  0.5401383054 -1.3278429554 -0.0870286339 -0.9200321168
## [156]  3.0637048543  0.0366253987  0.6159264510 -0.9848095514  1.0702410108
## [161]  2.2519934840  1.2521472479  3.2483253660  0.1560601148  0.2554054546
## [166] -1.3837918100  0.8997062858  1.5437618975  3.2200970376  4.2428268660
## [171]  4.8796814776  3.4944267802  3.5338487343  1.9056374923  3.8243441222
## [176]  2.6973660425  1.5586316888  1.0537138077  0.4735564378  0.8667967201
## [181] -0.3227890170 -1.2601457680 -1.6767524636 -0.5606943256 -0.5724867409
## [186] -0.7927487057 -3.7823291437 -3.1600153700 -3.3339550694 -0.5223037166
## [191]  1.3188603092  1.7841169179  3.2771554059  2.4302864848  1.9737979026
## [196]  0.3549837497 -0.5198143292 -0.6091253699 -0.5530998375 -0.0719700978
## [201]  0.1162479295  0.9584330444  0.6344896787  2.4637658099  2.2867046454
## [206]  1.5988556633  0.7653209481  0.3915332251 -0.0218611922  0.5574787959
## [211]  0.6001278409  2.0957927366  1.2982546155  1.5728132382  0.0805951955
## [216] -1.0094781239 -3.1290589551 -2.9867638935 -2.5487990772 -0.8746506343
## [221] -1.7204755510 -2.3373479869 -3.9397901303 -4.2603045521 -3.7080736007
## [226] -2.4567380560 -2.4451043371 -4.5475696207 -3.4437405213 -3.3531781238
## [231] -2.2477998694 -2.7793743188 -2.9892252870 -2.7065742281 -1.3646835008
## [236]  0.5205827432  0.1284297696  0.9535579764  1.4436000747  0.7192735976
## [241]  0.8655621589 -1.8247428875 -1.2940820209 -2.6010932672 -2.5683240349
## [246] -3.3390482543 -2.6056391336 -4.4232833523 -3.7565659797 -5.2443430811
## [251] -4.9963973684 -4.0655108800 -3.0676982101 -2.0284891531 -0.9220225427
## [256] -1.3180193115 -2.7850434151 -1.6722862864 -2.3760548989 -1.2871979057
## [261] -1.2457433091 -0.2704251019  0.4426094002  1.7244792000  1.6234544126
## [266]  1.2271504803  0.4637832128  0.8774865319 -0.1688721412 -0.7085067912
## [271] -0.9655544239 -0.4587798338 -1.6805074767 -0.4562603842 -1.2530770377
## [276] -0.4234566530  0.5792636344  2.0183639459  1.2335658487  2.4607872362
## [281]  0.5612596789  1.2593135541  0.8965377884  1.1050964502 -0.3891819897
## [286] -0.9852126937 -0.1110588970  0.2322458578  0.2510026152 -0.7146316233
## [291] -0.0134150381  0.2259188584 -0.0139370725 -0.1067440762  0.0047052158
## [296]  1.9459829310  1.1392060539
yt_3_arma22
##   [1] -1.0857429326  0.2019685297  0.5101006237  0.3116647978  1.1440157679
##   [6]  0.4568971792 -0.3804875233 -0.8758133113  0.3166261152  0.2548874061
##  [11]  0.2592079202 -0.3290331722 -0.2948120396  0.8417548499  2.0860897066
##  [16]  2.3426969416  3.4797265438  1.9702862497 -0.2703838028 -1.6091794075
##  [21] -2.9699033669 -4.6121759676 -3.5735246545 -4.6576056483 -3.2455887429
##  [26] -4.7021051669 -3.2231197169 -1.3940059863 -1.1346987187 -0.1752041013
##  [31]  1.0623014400  2.1418761113  4.7392121372  4.1182608009  4.0004548088
##  [36]  2.2502034531  3.0645576995  0.9645314951  1.7489003118  0.3724604884
##  [41]  2.9537132225  1.8162605804  1.0974763535  0.1760865572 -0.5446303408
##  [46] -0.9525033432 -0.8123258962 -1.3227469686 -1.5334325506 -0.9672480418
##  [51] -1.3288936550 -2.5250400524 -5.1130294931 -5.8037895789 -4.2935914351
##  [56] -2.2360988083  0.4460497638  1.7472096231  2.4006131137  0.7584947290
##  [61]  0.6515731377  1.2527039433 -1.8771638270 -1.8694819688 -2.5578881435
##  [66] -1.1519209603  0.5748330869  1.1471366303  1.8838444926  1.6757856446
##  [71]  0.6273297035 -0.9358028910 -1.3469021544 -2.0036326762 -2.3174267020
##  [76] -1.7545802003 -1.5599728217  0.6442232795 -0.4340053617 -0.1765772798
##  [81] -1.1300535322 -2.3487839887 -2.2931928545 -3.2830807993 -4.7019099638
##  [86] -4.5753666098 -5.1642557266 -2.7481221530 -2.8782203654 -0.9930444704
##  [91] -1.0689737305 -1.5783972995 -1.0380159333 -1.5332320899 -0.6261053110
##  [96]  0.0411088954  0.3721474367  2.2198607384  2.0023547146  1.1884673403
## [101]  1.3043018409 -0.7887107383 -2.0964309112 -3.5171926149 -4.3978707535
## [106] -4.2937125479 -2.1094795649  0.0003174271  1.9226494154  0.9593493745
## [111]  0.8134718138  0.3306846828  0.3997456277  0.6752169718 -0.5407546124
## [116] -1.6978244943 -0.6312219023 -0.5972690490  0.1183319718  0.2620479526
## [121]  2.1022412464  2.4863522906  4.4575844054  4.8757690067  4.3160857500
## [126]  4.5533945371  2.5494245996  0.9087801371 -1.2175736136 -1.9406110437
## [131] -0.1972454851  0.2476564511  0.4017020994  0.2225073455  0.5000164875
## [136] -0.5832769633 -1.3456109790 -3.9300614982 -4.9131646646 -5.8028221737
## [141] -5.2926716626 -3.0460358047 -1.3040226410  0.2132688421 -0.0784369871
## [146] -0.0996436572  0.1260353647 -0.2660236350  1.0782194035  1.7045666001
## [151]  0.9758460554  0.2737953256  0.5401383054 -1.3278429554 -0.0870286339
## [156] -0.9200321168  3.0637048543  0.0366253987  0.6159264510 -0.9848095514
## [161]  1.0702410108  2.2519934840  1.2521472479  3.2483253660  0.1560601148
## [166]  0.2554054546 -1.3837918100  0.8997062858  1.5437618975  3.2200970376
## [171]  4.2428268660  4.8796814776  3.4944267802  3.5338487343  1.9056374923
## [176]  3.8243441222  2.6973660425  1.5586316888  1.0537138077  0.4735564378
## [181]  0.8667967201 -0.3227890170 -1.2601457680 -1.6767524636 -0.5606943256
## [186] -0.5724867409 -0.7927487057 -3.7823291437 -3.1600153700 -3.3339550694
## [191] -0.5223037166  1.3188603092  1.7841169179  3.2771554059  2.4302864848
## [196]  1.9737979026  0.3549837497 -0.5198143292 -0.6091253699 -0.5530998375
## [201] -0.0719700978  0.1162479295  0.9584330444  0.6344896787  2.4637658099
## [206]  2.2867046454  1.5988556633  0.7653209481  0.3915332251 -0.0218611922
## [211]  0.5574787959  0.6001278409  2.0957927366  1.2982546155  1.5728132382
## [216]  0.0805951955 -1.0094781239 -3.1290589551 -2.9867638935 -2.5487990772
## [221] -0.8746506343 -1.7204755510 -2.3373479869 -3.9397901303 -4.2603045521
## [226] -3.7080736007 -2.4567380560 -2.4451043371 -4.5475696207 -3.4437405213
## [231] -3.3531781238 -2.2477998694 -2.7793743188 -2.9892252870 -2.7065742281
## [236] -1.3646835008  0.5205827432  0.1284297696  0.9535579764  1.4436000747
## [241]  0.7192735976  0.8655621589 -1.8247428875 -1.2940820209 -2.6010932672
## [246] -2.5683240349 -3.3390482543 -2.6056391336 -4.4232833523 -3.7565659797
## [251] -5.2443430811 -4.9963973684 -4.0655108800 -3.0676982101 -2.0284891531
## [256] -0.9220225427 -1.3180193115 -2.7850434151 -1.6722862864 -2.3760548989
## [261] -1.2871979057 -1.2457433091 -0.2704251019  0.4426094002  1.7244792000
## [266]  1.6234544126  1.2271504803  0.4637832128  0.8774865319 -0.1688721412
## [271] -0.7085067912 -0.9655544239 -0.4587798338 -1.6805074767 -0.4562603842
## [276] -1.2530770377 -0.4234566530  0.5792636344  2.0183639459  1.2335658487
## [281]  2.4607872362  0.5612596789  1.2593135541  0.8965377884  1.1050964502
## [286] -0.3891819897 -0.9852126937 -0.1110588970  0.2322458578  0.2510026152
## [291] -0.7146316233 -0.0134150381  0.2259188584 -0.0139370725 -0.1067440762
## [296]  0.0047052158  1.9459829310
# Scatterplot Yt vs Yt-1
plot(arma22[-n], arma22[-1],            
     main="Scatterplot Yt vs Yt-1", 
     xlab="Yt-1", ylab="Yt")

# Scatterplot Yt vs Yt-2
plot(arma22[-c(n, n-1)], arma22[-c(1,2)],
     main="Scatterplot Yt vs Yt-2", 
     xlab="Yt-2", ylab="Yt")

# Scatterplot Yt vs Yt-3
plot(arma22[-c(n, n-1, n-2)], 
     arma22[-c(1,2,3)],
     main="Scatterplot Yt vs Yt-3", 
     xlab="Yt-3", ylab="Yt")

Autokorelasi dari data bangkitan

# hitung ACF dari data bangkitan
acf_values <- acf(arma22, plot=FALSE)   

# tampilkan autokorelasi lag 1-3
acf_values$acf[2:4]                       
## [1] 0.6871620 0.4450373 0.2813706

Autokorelasi dari empiris

library(stats)

# Fungsi teoretis: gunakan ARMAacf
acf_theory <- ARMAacf(ar=c(0.5,0.2), ma=c(0.4,0.6), lag.max=10)
acf_theory[2:4]                          
##         1         2         3 
## 0.8591993 0.7491908 0.5464353

Hasil ACF, PACF, dan EACF menunnjukkan bahwa hasil simulai model ARMA(2,2) itu stationer karena

  • ACF tails off

  • PACF cut off di lag 2

  • EACF menunjukkan pola sesuai dengan MA(2) yaitu segitiga nol berada pada ordo MA(2)