library(readxl)
df <- read_excel("C:/Users/DEVINA/OneDrive/DOKUMEN EJA/ANREG/PROJECT ANREG/DATA PROJEK 2021.xlsx")
df
## # A tibble: 27 × 12
##        Y `Nama Kab/Kota`    X1    X2    X3    X4     X5     X6    X7    X8    X9
##    <dbl> <chr>           <dbl> <dbl> <dbl> <dbl>  <dbl>  <dbl> <dbl> <dbl> <dbl>
##  1 16821 KABUPATEN BOGOR  2585   1.3  53.0 59040 4.22e6 573352  62.4  74.4  87.5
##  2  6543 KABUPATEN SUKA…  1650   4.9  82.3 32883 3.13e6 362219  57.7  99.7 100  
##  3  5146 KABUPATEN CIAN…  2929   2.4  87.2 35113 2.53e6 442503  57.3  92.9 100  
##  4  9596 KABUPATEN BAND…  4238   2.3  95.4 40368 3.24e6 367264  65.5  90.3  74.6
##  5  5150 KABUPATEN GARUT  4194   3    89.1 19828 1.96e6 282908  58.5  96.6  81.5
##  6  4606 KABUPATEN TASI…  1641   4.2  90.5  6815 2.25e6 206987  59.8  79.3  84.6
##  7  1977 KABUPATEN CIAM…  1515   4    93.8  6602 1.88e6  96743  65.8  85.5  95.4
##  8  2461 KABUPATEN KUNI…  1346   5.5  77   11602 1.88e6 187029  60.0  90.1  80.3
##  9  7876 KABUPATEN CIRE…  1791   3.6  81.4 23029 2.27e6 189083  57.8  91.3  23.9
## 10  2471 KABUPATEN MAJA…   716   3.8  92.9 15717 2.01e6 211474  58.3  88.8  53.8
## # ℹ 17 more rows
## # ℹ 1 more variable: X10 <dbl>
data.projek <- df 
data.projek
## # A tibble: 27 × 12
##        Y `Nama Kab/Kota`    X1    X2    X3    X4     X5     X6    X7    X8    X9
##    <dbl> <chr>           <dbl> <dbl> <dbl> <dbl>  <dbl>  <dbl> <dbl> <dbl> <dbl>
##  1 16821 KABUPATEN BOGOR  2585   1.3  53.0 59040 4.22e6 573352  62.4  74.4  87.5
##  2  6543 KABUPATEN SUKA…  1650   4.9  82.3 32883 3.13e6 362219  57.7  99.7 100  
##  3  5146 KABUPATEN CIAN…  2929   2.4  87.2 35113 2.53e6 442503  57.3  92.9 100  
##  4  9596 KABUPATEN BAND…  4238   2.3  95.4 40368 3.24e6 367264  65.5  90.3  74.6
##  5  5150 KABUPATEN GARUT  4194   3    89.1 19828 1.96e6 282908  58.5  96.6  81.5
##  6  4606 KABUPATEN TASI…  1641   4.2  90.5  6815 2.25e6 206987  59.8  79.3  84.6
##  7  1977 KABUPATEN CIAM…  1515   4    93.8  6602 1.88e6  96743  65.8  85.5  95.4
##  8  2461 KABUPATEN KUNI…  1346   5.5  77   11602 1.88e6 187029  60.0  90.1  80.3
##  9  7876 KABUPATEN CIRE…  1791   3.6  81.4 23029 2.27e6 189083  57.8  91.3  23.9
## 10  2471 KABUPATEN MAJA…   716   3.8  92.9 15717 2.01e6 211474  58.3  88.8  53.8
## # ℹ 17 more rows
## # ℹ 1 more variable: X10 <dbl>

Eksplorasi Data Matriks Korelasi Data

model <- lm(Y ~ X1+X2+X3+X4+X5+X6+X7+X8+X9+X10 ,data= data.projek)
library(corrplot)
## corrplot 0.92 loaded
cor_mat <- cor(model$model[, -1])
corrplot(cor_mat, method = 'number')

Box Plot

par(mfrow=c(1,3))
boxplot(data.projek$Y,
        ylab = "Jumlah Balita Kurang Gizi",
        main = "Boxplot Jumlah Balita Kurang Gizi di Jawa Barat 2021", col="light blue")
boxplot(data.projek$X1,
        ylab = "Jumlah Posyandu Aktif (unit)",
        main = "Boxplot Jumlah Posyandu Aktif", col="light blue")
boxplot(data.projek$X2,
        ylab = "BBLR (%)",
        main = "Boxplot BBLR", col="light blue")

boxplot(data.projek$X3,
        ylab = "Inisiasi Menyusui Dini (%)",
        main = "Boxplot Inisiasi Menyusui Dini", col="light blue")
boxplot(data.projek$X4,
        ylab = "Bayi Penerima ASI Eksklusif (orang)",
        main = "Boxplot Bayi Penerima ASI Eksklusif", col="light blue")
boxplot(data.projek$X5,
        ylab = "Upah Minimum (Rp)",
        main = "Boxplot Upah Minimum", col="light blue")

boxplot(data.projek$X6,
        ylab = "Perilaku Hidup Bersih",
        main = "Boxplot Perilaku Hidup Bersih", col="light blue")
boxplot(data.projek$X7,
        ylab = "Indeks Pendidikan",
        main = "Boxplot Indeks Pendidikan", col="light blue")
boxplot(data.projek$X8,
        ylab = "Sanitasi Layak (%)",
        main = "Boxplot Sanitasi Layak", col="light blue")

boxplot(data.projek$X9,
        ylab = "Air Minum Memenuhi Syarat (%)",
        main = "Boxplot Air Minum Memenuhi SYarat", col="light blue")
boxplot(data.projek$X10,
        ylab = "TPM Memenuhi Syarat (%)",
        main = "Tempat Pengelolaan Makanan Memnuhi SYarat", col="light blue")

dataprojek <- read_xlsx("C:\\Users\\DEVINA\\OneDrive\\DOKUMEN EJA\\ANREG\\PROJECT ANREG\\DATA PROJEK 2021.xlsx", sheet = "Lembar2")
dataprojek
## # A tibble: 27 × 11
##        Y    X1    X2    X3    X4       X5     X6    X7    X8    X9   X10
##    <dbl> <dbl> <dbl> <dbl> <dbl>    <dbl>  <dbl> <dbl> <dbl> <dbl> <dbl>
##  1 16821  2585   1.3  53.0 59040 4217206  573352  62.4  74.4  87.5  23.8
##  2  6543  1650   4.9  82.3 32883 3125445. 362219  57.7  99.7 100    39.6
##  3  5146  2929   2.4  87.2 35113 2534799. 442503  57.3  92.9 100    60.3
##  4  9596  4238   2.3  95.4 40368 3241930. 367264  65.5  90.3  74.6  30.5
##  5  5150  4194   3    89.1 19828 1961086. 282908  58.5  96.6  81.5  55.1
##  6  4606  1641   4.2  90.5  6815 2251788. 206987  59.8  79.3  84.6  38.0
##  7  1977  1515   4    93.8  6602 1880655.  96743  65.8  85.5  95.4  55.6
##  8  2461  1346   5.5  77   11602 1882642. 187029  60.0  90.1  80.3  77  
##  9  7876  1791   3.6  81.4 23029 2269557. 189083  57.8  91.3  23.9  62.8
## 10  2471   716   3.8  92.9 15717 2009000  211474  58.3  88.8  53.8  62.1
## # ℹ 17 more rows
library(GGally)
## Loading required package: ggplot2
## Registered S3 method overwritten by 'GGally':
##   method from   
##   +.gg   ggplot2
ggpairs(dataprojek)

Model Regresi Awal

model <- lm(Y ~ X1+X2+X3+X4+X5+X6+X7+X8+X9+X10 ,data= data.projek)
model
## 
## Call:
## lm(formula = Y ~ X1 + X2 + X3 + X4 + X5 + X6 + X7 + X8 + X9 + 
##     X10, data = data.projek)
## 
## Coefficients:
## (Intercept)           X1           X2           X3           X4           X5  
##   5.334e+03    7.590e-01   -3.143e+01   -8.180e+01    1.624e-01    3.793e-04  
##          X6           X7           X8           X9          X10  
##  -1.763e-03    3.973e+01    9.542e+00   -4.724e-01   -3.182e+01
summary(model)
## 
## Call:
## lm(formula = Y ~ X1 + X2 + X3 + X4 + X5 + X6 + X7 + X8 + X9 + 
##     X10, data = data.projek)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -2281.4  -959.2  -433.6   856.5  3151.7 
## 
## Coefficients:
##               Estimate Std. Error t value Pr(>|t|)   
## (Intercept)  5.334e+03  5.945e+03   0.897  0.38291   
## X1           7.590e-01  5.770e-01   1.315  0.20696   
## X2          -3.143e+01  1.235e+02  -0.255  0.80230   
## X3          -8.180e+01  5.439e+01  -1.504  0.15210   
## X4           1.624e-01  5.338e-02   3.042  0.00777 **
## X5           3.793e-04  6.079e-04   0.624  0.54142   
## X6          -1.763e-03  4.790e-03  -0.368  0.71768   
## X7           3.973e+01  8.138e+01   0.488  0.63207   
## X8           9.542e+00  3.471e+01   0.275  0.78692   
## X9          -4.724e-01  2.115e+01  -0.022  0.98246   
## X10         -3.182e+01  2.450e+01  -1.299  0.21240   
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 1871 on 16 degrees of freedom
## Multiple R-squared:  0.8296, Adjusted R-squared:  0.7232 
## F-statistic: 7.792 on 10 and 16 DF,  p-value: 0.0001825

Eksplorasi Data -> masih error peubah y nya ga bisa masuk

library(corrplot)
cor_mat <- cor(model$model[, -1])
corrplot(cor_mat, method = 'number')

Pemeriksaan Multikolinieritas

library(car)
## Loading required package: carData
vif(model)
##       X1       X2       X3       X4       X5       X6       X7       X8 
## 2.773863 1.584947 1.794022 3.982359 2.810331 4.149471 2.290315 1.515883 
##       X9      X10 
## 1.636167 1.354969

multikolinieritas terjadi saat VIF > 10. Dalam kasus ini, tidak ada multikolinieritas antarvariabel. Oleh karena itu, dapat dilanjutkan ke tahap analisis berikutnya.

Regresi Klasik Regresi klasik tanpa peubah X4 dan X6

model2 <- lm(Y ~ X1+X2+X3+X5+X7+X8+X9+X10 ,data= data.projek)
model2
## 
## Call:
## lm(formula = Y ~ X1 + X2 + X3 + X5 + X7 + X8 + X9 + X10, data = data.projek)
## 
## Coefficients:
## (Intercept)           X1           X2           X3           X5           X7  
##   1.055e+04    2.049e+00   -7.167e+00   -1.619e+02    6.523e-04    4.022e+01  
##          X8           X9          X10  
##   1.530e+01   -5.979e+00   -2.114e+01
summary(model2)
## 
## Call:
## lm(formula = Y ~ X1 + X2 + X3 + X5 + X7 + X8 + X9 + X10, data = data.projek)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -3284.3 -1324.2  -330.3  1554.2  4180.8 
## 
## Coefficients:
##               Estimate Std. Error t value Pr(>|t|)   
## (Intercept)  1.055e+04  7.150e+03   1.476  0.15720   
## X1           2.049e+00  5.582e-01   3.671  0.00175 **
## X2          -7.167e+00  1.544e+02  -0.046  0.96349   
## X3          -1.619e+02  6.079e+01  -2.664  0.01581 * 
## X5           6.523e-04  6.296e-04   1.036  0.31388   
## X7           4.022e+01  9.005e+01   0.447  0.66050   
## X8           1.530e+01  4.352e+01   0.352  0.72925   
## X9          -5.979e+00  2.569e+01  -0.233  0.81862   
## X10         -2.114e+01  3.046e+01  -0.694  0.49657   
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 2354 on 18 degrees of freedom
## Multiple R-squared:  0.6968, Adjusted R-squared:  0.5621 
## F-statistic: 5.172 on 8 and 18 DF,  p-value: 0.001837

Regresi Gulud (Ridge) Korelasi terkuat ada di peubah X4 dan X6, jadi kita coba ilangin kedua peubah itu terus pake regresi gulud (ridge)

library(glmnet)
## Loading required package: Matrix
## Loaded glmnet 4.1-8
library(lmridge)
## 
## Attaching package: 'lmridge'
## The following object is masked from 'package:car':
## 
##     vif
lapply(c("glmnet","lmridge"),library,character.only=T)[[1]]
##  [1] "lmridge"   "glmnet"    "Matrix"    "car"       "carData"   "GGally"   
##  [7] "ggplot2"   "corrplot"  "readxl"    "stats"     "graphics"  "grDevices"
## [13] "utils"     "datasets"  "methods"   "base"
Y <- data.projek$Y
X1 <- data.projek$X1
X2 <- data.projek$X2
X3 <- data.projek$X3
X4 <- data.projek$X4
X5 <- data.projek$X5
X6 <- data.projek$X6
X7 <- data.projek$X7
X8 <- data.projek$X8
X9 <- data.projek$X9
X10 <- data.projek$X10
x <- cbind(X1,X2,X3,X4,X5,X6,X7,X8,X9,X10)
y <- data.projek$Y
cv.r <- cv.glmnet(x,y,alpha=0);plot(cv.r)
## Warning: Option grouped=FALSE enforced in cv.glmnet, since < 3 observations per
## fold

Best Model

best.lr <- cv.r$lambda.min
bestridge <- glmnet(x,y,alpha=0,lambda=best.lr);coef(bestridge)
## 11 x 1 sparse Matrix of class "dgCMatrix"
##                        s0
## (Intercept)  6.916611e+03
## X1           6.477050e-01
## X2          -4.212534e+01
## X3          -7.035041e+01
## X4           8.206597e-02
## X5           2.754074e-04
## X6           2.534253e-03
## X7           1.184373e+01
## X8           2.552332e+00
## X9           3.587638e+00
## X10         -2.678597e+01

Fungsi R square

rsq <- function(bestmodel,bestlambda,x,y) {
  # y duga
  y.duga <- predict(bestmodel, s = bestlambda, newx = x)
  
  #JKG dan JKT
  jkt <- sum((y-mean(y))^2)
  jkg <- sum((y.duga-y)^2)
  
  #find R-Squared
  rsq <- 1-jkg/jkt
  return(rsq)
}

Rsquare Ridge

rsq(bestridge,best.lr,x,y)
## [1] 0.7732472

Regresi Lasso

cv.l <- cv.glmnet(x,y,alpha=1);plot(cv.l)
## Warning: Option grouped=FALSE enforced in cv.glmnet, since < 3 observations per
## fold

best.ll <- cv.l$lambda.min
bestlasso <- glmnet(x,y,alpha=1,lambda=best.ll);coef(bestlasso)
## 11 x 1 sparse Matrix of class "dgCMatrix"
##                        s0
## (Intercept)  6.403101e+03
## X1           4.213773e-01
## X2           .           
## X3          -5.154793e+01
## X4           1.516273e-01
## X5           2.390044e-04
## X6           .           
## X7           .           
## X8           .           
## X9           .           
## X10         -2.590867e+01

MOdel yang kosong dikeluarkan sepenuhnya karena tidak cukup berpengaruh

rsq(bestlasso,best.ll ,x,y)
## [1] 0.8026896

Regresi Ridge (lmridge)

lmr <- lmridge(y~X1+X2+X3+X4+X5+X6+X7+X8+X9+X10,data=data.projek,scaling="centered")
plot(lmr)

summary(lmr)
## 
## Call:
## lmridge.default(formula = y ~ X1 + X2 + X3 + X4 + X5 + X6 + X7 + 
##     X8 + X9 + X10, data = data.projek, scaling = "centered")
## 
## 
## Coefficients: for Ridge parameter K= 0 
##            Estimate Estimate (Sc) StdErr (Sc) t-value (Sc) Pr(>|t|)   
## Intercept 5333.9841     5333.9841   8019.0705       0.6652   0.5154   
## X1           0.7590        0.7590      0.5598       1.3557   0.1940   
## X2         -31.4330      -31.4330    119.7921      -0.2624   0.7964   
## X3         -81.7988      -81.7988     52.7681      -1.5502   0.1407   
## X4           0.1624        0.1624      0.0518       3.1352   0.0064 **
## X5           0.0004        0.0004      0.0006       0.6432   0.5292   
## X6          -0.0018       -0.0018      0.0046      -0.3793   0.7094   
## X7          39.7266       39.7266     78.9519       0.5032   0.6217   
## X8           9.5423        9.5423     33.6762       0.2834   0.7805   
## X9          -0.4724       -0.4724     20.5217      -0.0230   0.9819   
## X10        -31.8211      -31.8211     23.7676      -1.3388   0.1993   
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Ridge Summary
##         R2     adj-R2   DF ridge          F        AIC        BIC 
##   0.829600   0.739500  10.000010   8.279126 412.729254 514.675231 
## Ridge minimum MSE= 25488.47 at K= 0 
## P-value for F-test ( 10.00001 , 17 ) = 9.04721e-05 
## -------------------------------------------------------------------
summary(model2)$r.squared
## [1] 0.6968431
rsq(bestridge,best.lr,x,y)
## [1] 0.7732472
rsq(bestlasso,best.ll ,x,y)
## [1] 0.8026896
summary(model2)$sigma
## [1] 2353.544
# Prediksi model ridge pada data pelatihan
train_predictionsridge <- predict(bestridge,newx = x)

# Hitung residu (selisih antara prediksi dan nilai sebenarnya)
residualsridge <- y - train_predictionsridge

# Hitung varian residu
dfridge <- length(y) - length(bestridge$beta)
residual_varianceridge <- sum(residualsridge^2) / dfridge

# Hitung RSE
rseridge <- sqrt(residual_varianceridge)

# Tampilkan hasil RSE
print(paste("Residual Standard Error (RSE):",rseridge))
## [1] "Residual Standard Error (RSE): 2094.48207564246"
# Prediksi model Lasso pada data pelatihan
train_predictionsLasso <- predict(bestlasso,newx = x)

# Hitung residu (selisih antara prediksi dan nilai sebenarnya)
residualsLasso <- y - train_predictionsLasso

# Hitung varian residu
dfLasso <- length(y) - length(bestlasso$beta)
residual_varianceLasso <- sum(residualsLasso^2) / dfLasso

# Hitung RSE
rseLasso <- sqrt(residual_varianceLasso)

# Tampilkan hasil RSE
print(paste("Residual Standard Error (RSE):",rseLasso))
## [1] "Residual Standard Error (RSE): 1953.77805136955"

Model Regresi Lasso memiliki R-Square paling besar dan RSE paling kecil. Jadi, model terbaik adalah Model Regresi Lasso (x1,x3,x4,x5,x10). Tapi x1,x4,x5 ga sesuai hiks

Pemeriksaan 𝜀(𝑖~𝑁)

Plot antara sisaan dan peluang normal Plot quantil quantil Pemeriksaan 𝐸[𝜀𝑖] = 0

Plot sisaan dan Y duga Plot sisaan dan X (Regresi linear sederhana)

plot(model,1) 

plot sisaan vs urutan sisaan saling bebas

plot(x = 1:dim(data.projek)[1],
     y = model$residuals,
     type = 'b', 
     ylab = "Residuals",
     xlab = "Observation")

Eksplorasi Normalitas Sisaan - qq-plot sisaan menyebar normal

plot(model,2)

Uji Formal Kondisi Gauss-Markov p-value < 0.05 tolak h0

1 Nilai harapan sisaan sama dengan nol

t.test(model$residuals,mu = 0,conf.level = 0.95)
## 
##  One Sample t-test
## 
## data:  model$residuals
## t = -1.043e-16, df = 26, p-value = 1
## alternative hypothesis: true mean is not equal to 0
## 95 percent confidence interval:
##  -580.7084  580.7084
## sample estimates:
##     mean of x 
## -2.946614e-14

2 Ragam sisaan homogen

library(lmtest)
## Loading required package: zoo
## 
## Attaching package: 'zoo'
## The following objects are masked from 'package:base':
## 
##     as.Date, as.Date.numeric
bptest(model)
## 
##  studentized Breusch-Pagan test
## 
## data:  model
## BP = 7.2485, df = 10, p-value = 0.7018
library(car)
ncvTest(model)
## Non-constant Variance Score Test 
## Variance formula: ~ fitted.values 
## Chisquare = 0.1938274, Df = 1, p = 0.65975

3 Sisaan saling bebas

library(randtests)
runs.test(model$residuals)
## 
##  Runs Test
## 
## data:  model$residuals
## statistic = 0.40032, runs = 15, n1 = 13, n2 = 13, n = 26, p-value =
## 0.6889
## alternative hypothesis: nonrandomness
library(lmtest)
dwtest(model)
## 
##  Durbin-Watson test
## 
## data:  model
## DW = 2.1037, p-value = 0.244
## alternative hypothesis: true autocorrelation is greater than 0

Uji Formal Normalitas Sisaan

ks.test(model$residuals, "pnorm", mean=mean(model$residuals), sd=sd(model$residuals))
## 
##  Exact one-sample Kolmogorov-Smirnov test
## 
## data:  model$residuals
## D = 0.13468, p-value = 0.6624
## alternative hypothesis: two-sided
library(car)
shapiro.test(model$residuals)
## 
##  Shapiro-Wilk normality test
## 
## data:  model$residuals
## W = 0.93972, p-value = 0.1199

H0: miu = 0

Interpretasi : p-value > \(\alpha\), maka tak Tolak H0, nilai harapan sisaan sama dengan nol.

H0: Saling bebas

Interpretasi : p-value > \(\alpha\), tak tolak H0, maka sisaan saling bebas.

H0: homogen

Interpretasi : p-value > \(\alpha\), maka tak tolak H0. Ragam sisaan homogen.

H0: Menyebar normal

Interpratsi : p-value > \(\alpha\), maka tak tolak Ho. Sisaan menyebar normal.

Pemeriksaan Amatan Berpengaruh Tabel hii, ri, Di

s <- sqrt(anova(model)["Residuals", "Mean Sq"])
n = dim(data.projek)[1]
p = length(model$coefficients)
hii=hatvalues(model)
Obs = c(1:n)
ei = model$residuals
ri = ei/(s*sqrt(1-hii))
Di = (ri^2/p)*(hii/(1-hii))
summ <- cbind.data.frame(Obs, data.projek, hii, ri, Di)

Pendeteksian Titik Laverage

for (i in 1:dim(summ)[1]){
  cutoff <- 2*p/n
  titik_leverage <- which(hii > cutoff)
}
titik_leverage
## 15 27 
## 15 27
summ_leverage <- subset(summ, Obs %in% titik_leverage)
summ_leverage <- subset(summ, Obs %in% titik_leverage, select = c("Obs","Nama Kab/Kota", "hii", "ri", "Di"))
summ_leverage
##    Obs      Nama Kab/Kota       hii         ri       Di
## 15  15 KABUPATEN KARAWANG 0.8151566 -1.9185287 1.475642
## 27  27        KOTA BANJAR 0.9630320  0.3837571 0.348767
library(dplyr)
## 
## Attaching package: 'dplyr'
## The following object is masked from 'package:car':
## 
##     recode
## The following objects are masked from 'package:stats':
## 
##     filter, lag
## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union
summ_leverage_sorted <- summ_leverage %>% 
  arrange(desc(hii))

summ_leverage_sorted
##    Obs      Nama Kab/Kota       hii         ri       Di
## 27  27        KOTA BANJAR 0.9630320  0.3837571 0.348767
## 15  15 KABUPATEN KARAWANG 0.8151566 -1.9185287 1.475642

Pendeteksian Pencilan

for (i in 1:dim(summ)[1]){
  absri <- abs(summ$ri)
  pencilan <- which(absri > 2)
}
pencilan
## [1] 16
summ_pencilan <- subset(summ, Obs %in% pencilan)
summ_pencilan <- subset(summ, Obs %in% pencilan, select = c("Obs","Nama Kab/Kota", "hii", "ri", "Di"))
summ_pencilan
##    Obs    Nama Kab/Kota       hii       ri        Di
## 16  16 KABUPATEN BEKASI 0.4945943 2.369059 0.4993073
library(dplyr)

summ_pencilan_sorted <- summ_pencilan %>% 
  arrange(desc(hii))

summ_pencilan_sorted
##    Obs    Nama Kab/Kota       hii       ri        Di
## 16  16 KABUPATEN BEKASI 0.4945943 2.369059 0.4993073

Pendeteksian Amatan Berpengaruh (Jarak COOK)

for (i in 1:dim(summ)[1]){
  fcrit = qf(p=0.95, df1=p, df2=n-p)
  amatan_berpengaruh <- which(Di > fcrit)
}
amatan_berpengaruh
## named integer(0)
summ_sorted <- summ %>% 
  arrange(desc(Di))

summ_sorted
##    Obs     Y           Nama Kab/Kota   X1   X2     X3    X4      X5     X6
## 15  15  2914      KABUPATEN KARAWANG 1595  2.8  78.47 13938 4798312 326480
## 1    1 16821         KABUPATEN BOGOR 2585  1.3  52.95 59040 4217206 573352
## 16  16  7548        KABUPATEN BEKASI 1752  0.5  88.85 17141 4791844 554077
## 27  27   727             KOTA BANJAR  200 21.0  84.59  1826 1831885  46517
## 9    9  7876       KABUPATEN CIREBON 1791  3.6  81.43 23029 2269557 189083
## 12  12  5973     KABUPATEN INDRAMAYU 1985  3.4  85.94  3656 2373073  45951
## 14  14  1228    KABUPATEN PURWAKARTA  704  2.3  78.68  7157 4173569 178321
## 23  23  7343             KOTA BEKASI 1357  1.9  78.99 13228 4782936  40596
## 3    3  5146       KABUPATEN CIANJUR 2929  2.4  87.23 35113 2534799 442503
## 5    5  5150         KABUPATEN GARUT 4194  3.0  89.12 19828 1961086 282908
## 6    6  4606   KABUPATEN TASIKMALAYA 1641  4.2  90.46  6815 2251788 206987
## 4    4  9596       KABUPATEN BANDUNG 4238  2.3  95.44 40368 3241930 367264
## 24  24  2397              KOTA DEPOK 1022  0.7  96.15 12379 4339515 347237
## 2    2  6543      KABUPATEN SUKABUMI 1650  4.9  82.26 32883 3125445 362219
## 26  26  2477        KOTA TASIKMALAYA  639  3.4  85.00  2628 2264093  73447
## 18  18   347   KABUPATEN PANGANDARAN  531  5.4  84.27  5120 1860591  94504
## 21  21  3941            KOTA BANDUNG 1423  1.6  78.84  4081 3742276  97979
## 25  25  1221             KOTA CIMAHI  391  2.4  85.18  3173 3241929  65195
## 20  20   621           KOTA SUKABUMI  378  3.8 100.00  1788 2530183  54842
## 13  13  2390        KABUPATEN SUBANG 1372  1.4  82.10  9488 3064218 266437
## 19  19  2824              KOTA BOGOR  203  1.7  95.85  7431 4169807 145792
## 17  17  5164 KABUPATEN BANDUNG BARAT 1858  1.8  78.46  8412 3248283 363351
## 8    8  2461      KABUPATEN KUNINGAN 1346  5.5  77.00 11602 1882642 187029
## 11  11  2381      KABUPATEN SUMEDANG 1264  2.5  88.11  9791 3241930 193165
## 10  10  2471    KABUPATEN MAJALENGKA  716  3.8  92.88 15717 2009000 211474
## 22  22  1108            KOTA CIREBON  264  4.9  81.69  2267 2271202  46322
## 7    7  1977        KABUPATEN CIAMIS 1515  4.0  93.79  6602 1880655  96743
##       X7     X8     X9   X10        hii          ri           Di
## 15 59.54  43.90  39.11 58.25 0.81515661 -1.91852868 1.475642e+00
## 1  62.39  74.45  87.52 23.76 0.77766868  1.50869238 7.237735e-01
## 16 67.39  91.33  95.49 66.35 0.49459430  2.36905861 4.993073e-01
## 27 66.01  97.97  86.40 54.78 0.96303205  0.38375708 3.487670e-01
## 9  57.75  91.32  23.89 62.75 0.47452090  1.86709469 2.861804e-01
## 12 55.79  82.06  74.30 33.36 0.35030627  1.95820886 1.879596e-01
## 14 60.67  94.45  48.58 49.34 0.36071511 -1.52478312 1.192596e-01
## 23 76.87  99.30  90.72 46.04 0.56496438  0.90440801 9.656781e-02
## 3  57.30  92.89 100.00 60.26 0.25620507 -1.41302478 6.252323e-02
## 5  58.52  96.65  81.47 55.12 0.50942403 -0.68807807 4.469469e-02
## 6  59.77  79.26  84.64 37.97 0.19209598  1.23649624 3.304848e-02
## 4  65.51  90.30  74.60 30.49 0.55611699 -0.53763262 3.292124e-02
## 24 76.89  90.29  59.31 56.69 0.39500031 -0.65524511 2.548339e-02
## 2  57.67  99.72 100.00 39.61 0.36884373 -0.65999434 2.314159e-02
## 26 69.12  57.86  22.91  9.17 0.62915620 -0.38053678 2.233408e-02
## 18 59.72  88.34  96.55 52.17 0.25054290 -0.74521605 1.687746e-02
## 21 76.11  78.49  96.36 24.45 0.36653852 -0.55872280 1.642100e-02
## 25 75.29  80.91  63.57 43.87 0.18155486 -0.78784080 1.251707e-02
## 20 70.42  83.20  72.17 72.89 0.26166010  0.56476172 1.027588e-02
## 13 56.23 100.00  72.17 51.79 0.22970855 -0.58737206 9.353108e-03
## 19 72.38  76.33  47.40 53.04 0.28328953  0.50812220 9.277489e-03
## 17 60.33 100.00  88.17 20.82 0.47709354  0.21443490 3.813974e-03
## 8  59.97  90.11  80.30 77.00 0.31516923 -0.28759930 3.460537e-03
## 11 64.46  95.84  78.98 51.82 0.08274138 -0.49903223 2.042187e-03
## 10 58.34  88.84  53.75 62.10 0.27533971  0.12905062 5.752570e-04
## 22 70.21  97.49  80.47 80.79 0.35560901  0.10066383 5.083672e-04
## 7  65.78  85.51  95.36 55.57 0.21295206  0.03629982 3.241134e-05
library(openxlsx)

# Tulis data frame ke file Excel
write.xlsx(summ_leverage_sorted, "summ_leverage_sorted.xlsx", rowNames = FALSE)
write.xlsx(summ_pencilan_sorted, "summ_pencilan_sorted.xlsx", rowNames = FALSE)
write.xlsx(amatan_berpengaruh, "amatan_berpengaruh.xlsx", rowNames = FALSE)
write.xlsx(summ_sorted, "summ_sorted.xlsx", rowNames = FALSE)

Plot Titik leverage dan pencilan

library(olsrr)
## 
## Attaching package: 'olsrr'
## The following object is masked from 'package:datasets':
## 
##     rivers
ols_plot_resid_lev(model)

hapus titik leverage dan pencilan

# Mendeteksi titik leverage, pencilan, dan amatan berpengaruh
cutoff <- 2*p/n
titik_leverage <- which(hii > cutoff)
absri <- abs(summ$ri)
pencilan <- which(absri > 2)
fcrit = qf(p=0.95, df1=p, df2=n-p)
amatan_berpengaruh <- which(Di > fcrit)

# Menggabungkan indeks titik leverage dan pencilan
observasi_kecuali_leverage_pencilan <- setdiff(1:n, c(titik_leverage, pencilan))

# Membuat data baru dengan menghapus titik leverage dan pencilan
data_regresi_no_leverage_pencilan <- data.projek[observasi_kecuali_leverage_pencilan,]

# Membuat model
model2 <- lm(Y ~ X1+X2+X3+X4+X5+X6+X7+X8+X9+X10 ,data= data_regresi_no_leverage_pencilan)
model2
## 
## Call:
## lm(formula = Y ~ X1 + X2 + X3 + X4 + X5 + X6 + X7 + X8 + X9 + 
##     X10, data = data_regresi_no_leverage_pencilan)
## 
## Coefficients:
## (Intercept)           X1           X2           X3           X4           X5  
##   1.395e+04    9.696e-01   -2.967e+01   -9.073e+01    1.913e-01    7.378e-04  
##          X6           X7           X8           X9          X10  
##  -8.149e-03   -3.271e+01   -3.340e+01   -4.460e+00   -2.461e+01
summary(model2)
## 
## Call:
## lm(formula = Y ~ X1 + X2 + X3 + X4 + X5 + X6 + X7 + X8 + X9 + 
##     X10, data = data_regresi_no_leverage_pencilan)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -2618.7  -766.3  -136.3   934.2  2037.2 
## 
## Coefficients:
##               Estimate Std. Error t value Pr(>|t|)  
## (Intercept)  1.395e+04  7.857e+03   1.775   0.0993 .
## X1           9.696e-01  6.561e-01   1.478   0.1633  
## X2          -2.967e+01  5.728e+02  -0.052   0.9595  
## X3          -9.073e+01  4.738e+01  -1.915   0.0778 .
## X4           1.913e-01  6.681e-02   2.864   0.0133 *
## X5           7.378e-04  9.896e-04   0.746   0.4692  
## X6          -8.149e-03  5.747e-03  -1.418   0.1798  
## X7          -3.271e+01  8.621e+01  -0.379   0.7105  
## X8          -3.340e+01  5.858e+01  -0.570   0.5783  
## X9          -4.460e+00  1.990e+01  -0.224   0.8261  
## X10         -2.461e+01  3.098e+01  -0.794   0.4413  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 1621 on 13 degrees of freedom
## Multiple R-squared:  0.8876, Adjusted R-squared:  0.8011 
## F-statistic: 10.26 on 10 and 13 DF,  p-value: 0.0001193

Alternatif Pemilihan Model Terbaik (OLS): Pemilihan Model Terbaik - Forward

library(olsrr)
##== Forward selection 
fw.hc <- ols_step_forward_p(model2)
fw.hc
## 
## 
##                              Stepwise Summary                              
## -------------------------------------------------------------------------
## Step    Variable        AIC        SBC       SBIC        R2       Adj. R2 
## -------------------------------------------------------------------------
##  0      Base Model    464.609    466.965    393.659    0.00000    0.00000 
##  1      X4            435.964    439.498    366.701    0.72109    0.70842 
##  2      X10           429.459    434.172    361.707    0.80431    0.78567 
##  3      X6            427.831    433.721    361.483    0.83177    0.80653 
##  4      X3            426.193    433.261    362.062    0.85543    0.82500 
##  5      X1            425.470    433.717    363.921    0.87093    0.83508 
##  6      X2            425.391    434.815    366.699    0.88165    0.83987 
## -------------------------------------------------------------------------
## 
## Final Model Output 
## ------------------
## 
##                             Model Summary                              
## ----------------------------------------------------------------------
## R                          0.939       RMSE                  1224.198 
## R-Squared                  0.882       MSE                2115757.867 
## Adj. R-Squared             0.840       Coef. Var               34.204 
## Pred R-Squared             0.737       AIC                    425.391 
## MAE                     1048.809       SBC                    434.815 
## ----------------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
##  AIC: Akaike Information Criteria 
##  SBC: Schwarz Bayesian Criteria 
## 
##                                   ANOVA                                    
## --------------------------------------------------------------------------
##                      Sum of                                               
##                     Squares        DF     Mean Square      F         Sig. 
## --------------------------------------------------------------------------
## Regression    267931050.094         6    44655175.016    21.106    0.0000 
## Residual       35967883.739        17     2115757.867                     
## Total         303898933.833        23                                     
## --------------------------------------------------------------------------
## 
##                                       Parameter Estimates                                        
## ------------------------------------------------------------------------------------------------
##       model         Beta    Std. Error    Std. Beta      t        Sig        lower        upper 
## ------------------------------------------------------------------------------------------------
## (Intercept)    12591.068      3358.965                  3.748    0.002    5504.270    19677.865 
##          X4        0.222         0.046        0.874     4.863    0.000       0.125        0.318 
##         X10      -38.296        19.859       -0.190    -1.928    0.071     -80.196        3.603 
##          X6       -0.009         0.004       -0.372    -2.266    0.037      -0.018       -0.001 
##          X3      -90.296        39.104       -0.235    -2.309    0.034    -172.798       -7.793 
##          X1        0.624         0.401        0.187     1.554    0.139      -0.223        1.470 
##          X2     -324.317       261.468       -0.121    -1.240    0.232    -875.966      227.332 
## ------------------------------------------------------------------------------------------------

Pemilihan Model Terbaik - Backward

##== Backward selection 
bw.hc <- ols_step_backward_p(model2)
bw.hc
## 
## 
##                              Stepwise Summary                              
## -------------------------------------------------------------------------
## Step    Variable        AIC        SBC       SBIC        R2       Adj. R2 
## -------------------------------------------------------------------------
##  0      Full Model    432.160    446.297    381.235    0.88756    0.80107 
##  1      X2            430.165    443.124    377.541    0.88754    0.81524 
##  2      X9            428.287    440.067    373.835    0.88697    0.82668 
##  3      X7            426.712    437.314    370.177    0.88495    0.83461 
##  4      X8            425.403    434.828    366.702    0.88159    0.83979 
## -------------------------------------------------------------------------
## 
## Final Model Output 
## ------------------
## 
##                             Model Summary                              
## ----------------------------------------------------------------------
## R                          0.939       RMSE                  1224.507 
## R-Squared                  0.882       MSE                2116825.919 
## Adj. R-Squared             0.840       Coef. Var               34.213 
## Pred R-Squared             0.723       AIC                    425.403 
## MAE                     1052.349       SBC                    434.828 
## ----------------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
##  AIC: Akaike Information Criteria 
##  SBC: Schwarz Bayesian Criteria 
## 
##                                   ANOVA                                    
## --------------------------------------------------------------------------
##                      Sum of                                               
##                     Squares        DF     Mean Square      F         Sig. 
## --------------------------------------------------------------------------
## Regression    267912893.204         6    44652148.867    21.094    0.0000 
## Residual       35986040.629        17     2116825.919                     
## Total         303898933.833        23                                     
## --------------------------------------------------------------------------
## 
##                                       Parameter Estimates                                       
## -----------------------------------------------------------------------------------------------
##       model        Beta    Std. Error    Std. Beta      t        Sig        lower        upper 
## -----------------------------------------------------------------------------------------------
## (Intercept)    9644.555      3601.144                  2.678    0.016    2046.806    17242.304 
##          X1       0.782         0.428        0.235     1.829    0.085      -0.120        1.684 
##          X3     -85.934        39.032       -0.224    -2.202    0.042    -168.283       -3.585 
##          X4       0.205         0.046        0.809     4.489    0.000       0.109        0.301 
##          X5       0.000         0.000        0.119     1.237    0.233       0.000        0.001 
##          X6      -0.008         0.004       -0.327    -2.097    0.051      -0.017        0.000 
##         X10     -39.282        19.599       -0.195    -2.004    0.061     -80.631        2.068 
## -----------------------------------------------------------------------------------------------

Pemilihan Model Terbaik - Stepwise

##== Stepwise
sw.hc <- ols_step_both_p(model2, details = T)
## Stepwise Selection Method 
## -------------------------
## 
## Candidate Terms: 
## 
## 1. X1 
## 2. X2 
## 3. X3 
## 4. X4 
## 5. X5 
## 6. X6 
## 7. X7 
## 8. X8 
## 9. X9 
## 10. X10 
## 
## 
## Step   => 0 
## Model  => Y ~ 1 
## R2     => 0 
## 
## Initiating stepwise selection... 
## 
## Step      => 1 
## Selected  => X4 
## Model     => Y ~ X4 
## R2        => 0.721 
## 
## Step      => 2 
## Selected  => X10 
## Model     => Y ~ X4 + X10 
## R2        => 0.804 
## 
## Step      => 3 
## Selected  => X6 
## Model     => Y ~ X4 + X10 + X6 
## R2        => 0.832 
## 
## Step      => 4 
## Selected  => X3 
## Model     => Y ~ X4 + X10 + X6 + X3 
## R2        => 0.855 
## 
## 
## No more variables to be added or removed.
sw.hc
## 
## 
##                              Stepwise Summary                              
## -------------------------------------------------------------------------
## Step    Variable        AIC        SBC       SBIC        R2       Adj. R2 
## -------------------------------------------------------------------------
##  0      Base Model    464.609    466.965    393.659    0.00000    0.00000 
##  1      X4 (+)        435.964    439.498    366.701    0.72109    0.70842 
##  2      X10 (+)       429.459    434.172    361.707    0.80431    0.78567 
##  3      X6 (+)        427.831    433.721    361.483    0.83177    0.80653 
##  4      X3 (+)        426.193    433.261    362.062    0.85543    0.82500 
## -------------------------------------------------------------------------
## 
## Final Model Output 
## ------------------
## 
##                             Model Summary                              
## ----------------------------------------------------------------------
## R                          0.925       RMSE                  1352.994 
## R-Squared                  0.855       MSE                2312328.588 
## Adj. R-Squared             0.825       Coef. Var               35.758 
## Pred R-Squared             0.757       AIC                    426.193 
## MAE                     1130.762       SBC                    433.261 
## ----------------------------------------------------------------------
##  RMSE: Root Mean Square Error 
##  MSE: Mean Square Error 
##  MAE: Mean Absolute Error 
##  AIC: Akaike Information Criteria 
##  SBC: Schwarz Bayesian Criteria 
## 
##                                   ANOVA                                    
## --------------------------------------------------------------------------
##                      Sum of                                               
##                     Squares        DF     Mean Square      F         Sig. 
## --------------------------------------------------------------------------
## Regression    259964690.668         4    64991172.667    28.106    0.0000 
## Residual       43934243.165        19     2312328.588                     
## Total         303898933.833        23                                     
## --------------------------------------------------------------------------
## 
##                                       Parameter Estimates                                        
## ------------------------------------------------------------------------------------------------
##       model         Beta    Std. Error    Std. Beta      t        Sig        lower        upper 
## ------------------------------------------------------------------------------------------------
## (Intercept)    10645.648      3340.833                  3.187    0.005    3653.205    17638.092 
##          X4        0.244         0.042        0.962     5.763    0.000       0.155        0.332 
##         X10      -54.169        18.741       -0.268    -2.890    0.009     -93.394      -14.945 
##          X6       -0.007         0.004       -0.285    -1.766    0.093      -0.016        0.001 
##          X3      -67.988        38.554       -0.177    -1.763    0.094    -148.682       12.706 
## ------------------------------------------------------------------------------------------------

Best Subset Regression # Hald Cement data

bs.hc <- ols_step_best_subset(model2)
bs.hc
##            Best Subsets Regression           
## ---------------------------------------------
## Model Index    Predictors
## ---------------------------------------------
##      1         X4                             
##      2         X4 X10                         
##      3         X4 X6 X10                      
##      4         X3 X4 X6 X10                   
##      5         X1 X3 X4 X6 X10                
##      6         X1 X2 X3 X4 X6 X10             
##      7         X1 X3 X4 X5 X6 X8 X10          
##      8         X1 X3 X4 X5 X6 X7 X8 X10       
##      9         X1 X3 X4 X5 X6 X7 X8 X9 X10    
##     10         X1 X2 X3 X4 X5 X6 X7 X8 X9 X10 
## ---------------------------------------------
## 
##                                                             Subsets Regression Summary                                                            
## --------------------------------------------------------------------------------------------------------------------------------------------------
##                        Adj.        Pred                                                                                                            
## Model    R-Square    R-Square    R-Square     C(p)        AIC         SBIC        SBC           MSEP             FPE             HSP         APC  
## --------------------------------------------------------------------------------------------------------------------------------------------------
##   1        0.7211      0.7084        0.61    12.2468    435.9635    366.7007    439.4977    92495138.1121    4173747.5545    183461.4310    0.3296 
##   2        0.8043      0.7857      0.7109     4.6255    429.4593    361.7074    434.1716    68142700.1078    3185892.4726    141595.2210    0.2516 
##   3        0.8318      0.8065      0.7019     3.4507    427.8306    361.4833    433.7209    61664068.5078    2982298.5860    134539.7858    0.2355 
##   4        0.8554      0.8250      0.7569     2.7149    426.1927    362.0622    433.2610    55934800.3260    2794063.7101    128462.6993    0.2207 
##   5        0.8709      0.8351      0.7213     2.9225    425.4703    363.9209    433.7167    52874162.0640    2723820.4700    128179.7868    0.2151 
##   6        0.8816      0.8399      0.7372     3.6841    425.3910    366.6995    434.8155    51516500.1468    2732853.9115    132234.8667    0.2158 
##   7        0.8849      0.8346      0.6484     5.3022    426.7118    370.1766    437.3143    53417565.5674    2913685.3946    145684.2697    0.2301 
##   8        0.8870      0.8267       0.586     7.0687    428.2867    373.8345    440.0672    56228185.5918    3148778.3931    163572.9035    0.2487 
##   9        0.8875      0.8152      0.4643     9.0027    430.1652    377.5410    443.1238    60247762.4880    3458378.0545    187785.2337    0.2731 
##  10        0.8876      0.8011      0.3962    11.0000    432.1603    381.2346    446.2969    65254944.3940    3833157.5728    219037.5756    0.3027 
## --------------------------------------------------------------------------------------------------------------------------------------------------
## AIC: Akaike Information Criteria 
##  SBIC: Sawa's Bayesian Information Criteria 
##  SBC: Schwarz Bayesian Criteria 
##  MSEP: Estimated error of prediction, assuming multivariate normality 
##  FPE: Final Prediction Error 
##  HSP: Hocking's Sp 
##  APC: Amemiya Prediction Criteria
best_model <- lm(Y~ X3 + X4+ X6 + X10 , data = data_regresi_no_leverage_pencilan)
best_model
## 
## Call:
## lm(formula = Y ~ X3 + X4 + X6 + X10, data = data_regresi_no_leverage_pencilan)
## 
## Coefficients:
## (Intercept)           X3           X4           X6          X10  
##   1.065e+04   -6.799e+01    2.436e-01   -7.196e-03   -5.417e+01
summary(best_model)
## 
## Call:
## lm(formula = Y ~ X3 + X4 + X6 + X10, data = data_regresi_no_leverage_pencilan)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -2310.6  -992.8  -147.7   815.6  2417.3 
## 
## Coefficients:
##               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  1.065e+04  3.341e+03   3.187  0.00486 ** 
## X3          -6.799e+01  3.855e+01  -1.763  0.09390 .  
## X4           2.436e-01  4.227e-02   5.763 1.49e-05 ***
## X6          -7.196e-03  4.074e-03  -1.766  0.09345 .  
## X10         -5.417e+01  1.874e+01  -2.890  0.00937 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 1521 on 19 degrees of freedom
## Multiple R-squared:  0.8554, Adjusted R-squared:  0.825 
## F-statistic: 28.11 on 4 and 19 DF,  p-value: 9.572e-08

Uji Asumsi Model Terbaik

#  ===== Eksplorasi asumsi =====
plot(best_model,1)                # plot sisaan vs yduga

plot(best_model,2)                # qq-plot

plot(x = 1:dim(data_regresi_no_leverage_pencilan)[1],
     y = best_model$residuals,
     type = 'b', 
     ylab = "Residuals",
     xlab = "Observation")       # plot sisaan vs urutan

Regresi Gulud

Uji Asumsi: Metode Formal

# Asumsi Gauss-Markov: Nilai harapan sisaan sama dengan nol
t.test(best_model$residuals,
       mu = 0,
       conf.level = 0.95)
## 
##  One Sample t-test
## 
## data:  best_model$residuals
## t = 1.805e-16, df = 23, p-value = 1
## alternative hypothesis: true mean is not equal to 0
## 95 percent confidence interval:
##  -583.6072  583.6072
## sample estimates:
##    mean of x 
## 5.092223e-14
# Asumsi Gauss-Markov: Sisaan saling bebas
library(randtests)
runs.test(best_model$residuals)
## 
##  Runs Test
## 
## data:  best_model$residuals
## statistic = 0.41742, runs = 14, n1 = 12, n2 = 12, n = 24, p-value =
## 0.6764
## alternative hypothesis: nonrandomness
# Asumsi Gauss-Markov: Ragam Sisaan Homogen
ncvTest(best_model)
## Non-constant Variance Score Test 
## Variance formula: ~ fitted.values 
## Chisquare = 0.008171531, Df = 1, p = 0.92797
# Asumsi Normalitas Sisaan
shapiro.test(best_model$residuals)
## 
##  Shapiro-Wilk normality test
## 
## data:  best_model$residuals
## W = 0.95503, p-value = 0.3469

H0: miu = 0

Interpretasi : p-value > \(\alpha\), maka tak Tolak H0, nilai harapan sisaan sama dengan nol.

H0: Saling bebas

Interpretasi : p-value > \(\alpha\), tak tolak H0, maka sisaan saling bebas.

H0: homogen

Interpretasi : p-value > \(\alpha\), maka tak tolak H0. Ragam sisaan homogen.

H0: Menyebar normal

Interpratsi : p-value > \(\alpha\), maka tak tolak Ho. Sisaan menyebar normal.

Pengujian Kelayakan Model

summary.lm(best_model)
## 
## Call:
## lm(formula = Y ~ X3 + X4 + X6 + X10, data = data_regresi_no_leverage_pencilan)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -2310.6  -992.8  -147.7   815.6  2417.3 
## 
## Coefficients:
##               Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  1.065e+04  3.341e+03   3.187  0.00486 ** 
## X3          -6.799e+01  3.855e+01  -1.763  0.09390 .  
## X4           2.436e-01  4.227e-02   5.763 1.49e-05 ***
## X6          -7.196e-03  4.074e-03  -1.766  0.09345 .  
## X10         -5.417e+01  1.874e+01  -2.890  0.00937 ** 
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 1521 on 19 degrees of freedom
## Multiple R-squared:  0.8554, Adjusted R-squared:  0.825 
## F-statistic: 28.11 on 4 and 19 DF,  p-value: 9.572e-08
anova(best_model)
## Analysis of Variance Table
## 
## Response: Y
##           Df    Sum Sq   Mean Sq F value    Pr(>F)    
## X3         1 101803395 101803395 44.0264 2.393e-06 ***
## X4         1 134295208 134295208 58.0779 3.421e-07 ***
## X6         1   4546766   4546766  1.9663  0.176967    
## X10        1  19319322  19319322  8.3549  0.009372 ** 
## Residuals 19  43934243   2312329                      
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
aov(best_model)
## Call:
##    aov(formula = best_model)
## 
## Terms:
##                        X3        X4        X6       X10 Residuals
## Sum of Squares  101803395 134295208   4546766  19319322  43934243
## Deg. of Freedom         1         1         1         1        19
## 
## Residual standard error: 1520.634
## Estimated effects may be unbalanced