Tentang data

Dimensi data

dim(df)
## [1] 284807     31

Variable

str(df)
## Classes 'spec_tbl_df', 'tbl_df', 'tbl' and 'data.frame': 284807 obs. of  31 variables:
##  $ Time  : num  0 0 1 1 2 2 4 7 7 9 ...
##  $ V1    : num  -1.36 1.192 -1.358 -0.966 -1.158 ...
##  $ V2    : num  -0.0728 0.2662 -1.3402 -0.1852 0.8777 ...
##  $ V3    : num  2.536 0.166 1.773 1.793 1.549 ...
##  $ V4    : num  1.378 0.448 0.38 -0.863 0.403 ...
##  $ V5    : num  -0.3383 0.06 -0.5032 -0.0103 -0.4072 ...
##  $ V6    : num  0.4624 -0.0824 1.8005 1.2472 0.0959 ...
##  $ V7    : num  0.2396 -0.0788 0.7915 0.2376 0.5929 ...
##  $ V8    : num  0.0987 0.0851 0.2477 0.3774 -0.2705 ...
##  $ V9    : num  0.364 -0.255 -1.515 -1.387 0.818 ...
##  $ V10   : num  0.0908 -0.167 0.2076 -0.055 0.7531 ...
##  $ V11   : num  -0.552 1.613 0.625 -0.226 -0.823 ...
##  $ V12   : num  -0.6178 1.0652 0.0661 0.1782 0.5382 ...
##  $ V13   : num  -0.991 0.489 0.717 0.508 1.346 ...
##  $ V14   : num  -0.311 -0.144 -0.166 -0.288 -1.12 ...
##  $ V15   : num  1.468 0.636 2.346 -0.631 0.175 ...
##  $ V16   : num  -0.47 0.464 -2.89 -1.06 -0.451 ...
##  $ V17   : num  0.208 -0.115 1.11 -0.684 -0.237 ...
##  $ V18   : num  0.0258 -0.1834 -0.1214 1.9658 -0.0382 ...
##  $ V19   : num  0.404 -0.146 -2.262 -1.233 0.803 ...
##  $ V20   : num  0.2514 -0.0691 0.525 -0.208 0.4085 ...
##  $ V21   : num  -0.01831 -0.22578 0.248 -0.1083 -0.00943 ...
##  $ V22   : num  0.27784 -0.63867 0.77168 0.00527 0.79828 ...
##  $ V23   : num  -0.11 0.101 0.909 -0.19 -0.137 ...
##  $ V24   : num  0.0669 -0.3398 -0.6893 -1.1756 0.1413 ...
##  $ V25   : num  0.129 0.167 -0.328 0.647 -0.206 ...
##  $ V26   : num  -0.189 0.126 -0.139 -0.222 0.502 ...
##  $ V27   : num  0.13356 -0.00898 -0.05535 0.06272 0.21942 ...
##  $ V28   : num  -0.0211 0.0147 -0.0598 0.0615 0.2152 ...
##  $ Amount: num  149.62 2.69 378.66 123.5 69.99 ...
##  $ Class : num  0 0 0 0 0 0 0 0 0 0 ...
##  - attr(*, "spec")=
##   .. cols(
##   ..   Time = col_double(),
##   ..   V1 = col_double(),
##   ..   V2 = col_double(),
##   ..   V3 = col_double(),
##   ..   V4 = col_double(),
##   ..   V5 = col_double(),
##   ..   V6 = col_double(),
##   ..   V7 = col_double(),
##   ..   V8 = col_double(),
##   ..   V9 = col_double(),
##   ..   V10 = col_double(),
##   ..   V11 = col_double(),
##   ..   V12 = col_double(),
##   ..   V13 = col_double(),
##   ..   V14 = col_double(),
##   ..   V15 = col_double(),
##   ..   V16 = col_double(),
##   ..   V17 = col_double(),
##   ..   V18 = col_double(),
##   ..   V19 = col_double(),
##   ..   V20 = col_double(),
##   ..   V21 = col_double(),
##   ..   V22 = col_double(),
##   ..   V23 = col_double(),
##   ..   V24 = col_double(),
##   ..   V25 = col_double(),
##   ..   V26 = col_double(),
##   ..   V27 = col_double(),
##   ..   V28 = col_double(),
##   ..   Amount = col_double(),
##   ..   Class = col_double()
##   .. )

Cek data yang kosong

any(is.na(df))
## [1] FALSE
summary(df)
##       Time              V1                  V2                  V3          
##  Min.   :     0   Min.   :-56.40751   Min.   :-72.71573   Min.   :-48.3256  
##  1st Qu.: 54202   1st Qu.: -0.92037   1st Qu.: -0.59855   1st Qu.: -0.8904  
##  Median : 84692   Median :  0.01811   Median :  0.06549   Median :  0.1799  
##  Mean   : 94814   Mean   :  0.00000   Mean   :  0.00000   Mean   :  0.0000  
##  3rd Qu.:139321   3rd Qu.:  1.31564   3rd Qu.:  0.80372   3rd Qu.:  1.0272  
##  Max.   :172792   Max.   :  2.45493   Max.   : 22.05773   Max.   :  9.3826  
##        V4                 V5                   V6                 V7          
##  Min.   :-5.68317   Min.   :-113.74331   Min.   :-26.1605   Min.   :-43.5572  
##  1st Qu.:-0.84864   1st Qu.:  -0.69160   1st Qu.: -0.7683   1st Qu.: -0.5541  
##  Median :-0.01985   Median :  -0.05434   Median : -0.2742   Median :  0.0401  
##  Mean   : 0.00000   Mean   :   0.00000   Mean   :  0.0000   Mean   :  0.0000  
##  3rd Qu.: 0.74334   3rd Qu.:   0.61193   3rd Qu.:  0.3986   3rd Qu.:  0.5704  
##  Max.   :16.87534   Max.   :  34.80167   Max.   : 73.3016   Max.   :120.5895  
##        V8                  V9                 V10                 V11          
##  Min.   :-73.21672   Min.   :-13.43407   Min.   :-24.58826   Min.   :-4.79747  
##  1st Qu.: -0.20863   1st Qu.: -0.64310   1st Qu.: -0.53543   1st Qu.:-0.76249  
##  Median :  0.02236   Median : -0.05143   Median : -0.09292   Median :-0.03276  
##  Mean   :  0.00000   Mean   :  0.00000   Mean   :  0.00000   Mean   : 0.00000  
##  3rd Qu.:  0.32735   3rd Qu.:  0.59714   3rd Qu.:  0.45392   3rd Qu.: 0.73959  
##  Max.   : 20.00721   Max.   : 15.59500   Max.   : 23.74514   Max.   :12.01891  
##       V12                V13                V14                V15          
##  Min.   :-18.6837   Min.   :-5.79188   Min.   :-19.2143   Min.   :-4.49894  
##  1st Qu.: -0.4056   1st Qu.:-0.64854   1st Qu.: -0.4256   1st Qu.:-0.58288  
##  Median :  0.1400   Median :-0.01357   Median :  0.0506   Median : 0.04807  
##  Mean   :  0.0000   Mean   : 0.00000   Mean   :  0.0000   Mean   : 0.00000  
##  3rd Qu.:  0.6182   3rd Qu.: 0.66251   3rd Qu.:  0.4931   3rd Qu.: 0.64882  
##  Max.   :  7.8484   Max.   : 7.12688   Max.   : 10.5268   Max.   : 8.87774  
##       V16                 V17                 V18           
##  Min.   :-14.12985   Min.   :-25.16280   Min.   :-9.498746  
##  1st Qu.: -0.46804   1st Qu.: -0.48375   1st Qu.:-0.498850  
##  Median :  0.06641   Median : -0.06568   Median :-0.003636  
##  Mean   :  0.00000   Mean   :  0.00000   Mean   : 0.000000  
##  3rd Qu.:  0.52330   3rd Qu.:  0.39968   3rd Qu.: 0.500807  
##  Max.   : 17.31511   Max.   :  9.25353   Max.   : 5.041069  
##       V19                 V20                 V21           
##  Min.   :-7.213527   Min.   :-54.49772   Min.   :-34.83038  
##  1st Qu.:-0.456299   1st Qu.: -0.21172   1st Qu.: -0.22839  
##  Median : 0.003735   Median : -0.06248   Median : -0.02945  
##  Mean   : 0.000000   Mean   :  0.00000   Mean   :  0.00000  
##  3rd Qu.: 0.458949   3rd Qu.:  0.13304   3rd Qu.:  0.18638  
##  Max.   : 5.591971   Max.   : 39.42090   Max.   : 27.20284  
##       V22                  V23                 V24          
##  Min.   :-10.933144   Min.   :-44.80774   Min.   :-2.83663  
##  1st Qu.: -0.542350   1st Qu.: -0.16185   1st Qu.:-0.35459  
##  Median :  0.006782   Median : -0.01119   Median : 0.04098  
##  Mean   :  0.000000   Mean   :  0.00000   Mean   : 0.00000  
##  3rd Qu.:  0.528554   3rd Qu.:  0.14764   3rd Qu.: 0.43953  
##  Max.   : 10.503090   Max.   : 22.52841   Max.   : 4.58455  
##       V25                 V26                V27            
##  Min.   :-10.29540   Min.   :-2.60455   Min.   :-22.565679  
##  1st Qu.: -0.31715   1st Qu.:-0.32698   1st Qu.: -0.070840  
##  Median :  0.01659   Median :-0.05214   Median :  0.001342  
##  Mean   :  0.00000   Mean   : 0.00000   Mean   :  0.000000  
##  3rd Qu.:  0.35072   3rd Qu.: 0.24095   3rd Qu.:  0.091045  
##  Max.   :  7.51959   Max.   : 3.51735   Max.   : 31.612198  
##       V28                Amount             Class         
##  Min.   :-15.43008   Min.   :    0.00   Min.   :0.000000  
##  1st Qu.: -0.05296   1st Qu.:    5.60   1st Qu.:0.000000  
##  Median :  0.01124   Median :   22.00   Median :0.000000  
##  Mean   :  0.00000   Mean   :   88.35   Mean   :0.001728  
##  3rd Qu.:  0.07828   3rd Qu.:   77.17   3rd Qu.:0.000000  
##  Max.   : 33.84781   Max.   :25691.16   Max.   :1.000000

Konversi variabel Class ke factor

df$Class <- as.factor(df$Class)

Splitting data and training and testing

sample <- sample.split(df$Class, SplitRatio = 0.7)
train <- subset(df, sample == T)
test <- subset(df, sample == F)

Model logistic

model <- glm(Class ~ . , family = binomial(link='logit'),data = train)

Prediksi model

predicted.values <- predict(model,newdata=test,type='response')

Cek Akurasi model

results <- ifelse(predicted.values > 0.5,1,0)
# artinya jika hasil prediksi > 0.5 adalah 1(fraud), 0(normal)

c <- table(test$Class,results)#membuat table matrik untuk akurasi
c
##    results
##         0     1
##   0 85285    10
##   1    48   100

Hasil akurasi

library(caret)#regressing and accuracy  
## Warning: package 'caret' was built under R version 3.5.3
## Loading required package: lattice
## Loading required package: ggplot2
## Warning: package 'ggplot2' was built under R version 3.5.3
confusionMatrix(c)
## Confusion Matrix and Statistics
## 
##    results
##         0     1
##   0 85285    10
##   1    48   100
##                                           
##                Accuracy : 0.9993          
##                  95% CI : (0.9991, 0.9995)
##     No Information Rate : 0.9987          
##     P-Value [Acc > NIR] : 3.690e-08       
##                                           
##                   Kappa : 0.7749          
##                                           
##  Mcnemar's Test P-Value : 1.184e-06       
##                                           
##             Sensitivity : 0.9994          
##             Specificity : 0.9091          
##          Pos Pred Value : 0.9999          
##          Neg Pred Value : 0.6757          
##              Prevalence : 0.9987          
##          Detection Rate : 0.9982          
##    Detection Prevalence : 0.9983          
##       Balanced Accuracy : 0.9543          
##                                           
##        'Positive' Class : 0               
## 

Visualisasi

p <- ggplot(df,aes(x = df$Class, fill="red")) + 
  geom_bar(position = "dodge", alpha = 0.5, col ="black") +
  scale_x_discrete( name = "Is it Fraud?") +
  scale_y_continuous() + 
  ggtitle("Fraud Case Classes, 1=Fraud,0=Normal") +
  theme(plot.title = element_text(hjust = 0.5))
p