Menghitung Means, Varian-Covarian, Korelasi Beserta Visualisasi Data

Penerima Beasiswa

x1 <- c(3.75,3.69,3.78,2.83,3.85,2.92,3.85,3.88,3.89,3.86) # Buat vektor x1 dalam hal ini Indeks Prestasi (IP)
x2 <- c(450,2200,1300,2200,450,2200,1300,450,450,1300) # Buat vektor x2 dalam hal ini Daya listrik (VA)
x3 <- c(825882,538182,679670,942130,616478,284606,710103,983355,893746,327686) # Buat vektor x3 dalam hal ini Jumlah tagihan listrik (Rp)
data1.1 <- data.frame(x1,x2,x3)

library(scatterplot3d)
scatterplot3d(data1.1, main="3D Scatterplot", pch=20) 

Melakukan penghitungan rata-rata pada tiap kolom di data1.1

xbar1.1 <- colMeans(data1.1) 
print("Vector Means : ")

## [1] "Vector Means : "

print(xbar1.1)

##        x1        x2        x3 
##      3.63   1230.00 680183.80

Melakukan penghitungan matriks varian-kovarian

variance <- function(x){
  x = as.numeric(x)
  x = na.omit(x)
  m = mean(x)
  return(
    sum((x-m)^2, na.rm = TRUE)/(length(x) - 1)
  )
}

matriks1.1 <- cov(data1.1) 
print("Matriks varians-kovarians : ")

## [1] "Matriks varians-kovarians : "

print(matriks1.1) # Matriks varians-kovarians

##               x1            x2            x3
## x1     0.1627111 -2.252778e+02  1.366681e+04
## x2  -225.2777778  5.856667e+05 -8.410967e+07
## x3 13666.8122222 -8.410967e+07  5.924669e+10

Melakukan penghitungan matriks korelasi

print("Matriks korelasi : ")

## [1] "Matriks korelasi : "

korelasi <- cov2cor(matriks1.1)
korelasi # Matriks korelasi

##            x1         x2         x3
## x1  1.0000000 -0.7297675  0.1391959
## x2 -0.7297675  1.0000000 -0.4515321
## x3  0.1391959 -0.4515321  1.0000000

Visualisasi Data Means

print("Visualisasi data Means : ")

## [1] "Visualisasi data Means : "

plot(xbar1.1)

pie(table(xbar1.1))

Visualisasi data Varian-Covarian

print("Visualisasi data Varian-Covarian : ")

## [1] "Visualisasi data Varian-Covarian : "

scatterplot3d(matriks1.1, main="3D Scatterplot", pch=20) 

Visualisasi data Korelasi

print("Visualisasi data Korelasi : ")

## [1] "Visualisasi data Korelasi : "

scatterplot3d(korelasi, main="3D Scatterplot", pch=20)