getwd()
## [1] "C:/Users/Dell/Downloads/BigDiamonds.csv"
setwd("C:/Users/Dell/Downloads/")
dir(pattern='csv')
##  [1] "AirPassengers.csv"                   
##  [2] "BigDiamonds.csv"                     
##  [3] "BigDiamonds.csv (1).zip"             
##  [4] "BigDiamonds.csv (2)"                 
##  [5] "BigDiamonds.csv (2).zip"             
##  [6] "BigDiamonds.csv (3).zip"             
##  [7] "BigDiamonds.csv.zip"                 
##  [8] "Boston (1).csv"                      
##  [9] "Boston.csv"                          
## [10] "ccFraud.csv"                         
## [11] "class2.csv"                          
## [12] "data1.csv"                           
## [13] "datasets.csv"                        
## [14] "Diamond (1).csv"                     
## [15] "Diamond (2).csv"                     
## [16] "Diamond (3).csv"                     
## [17] "Diamond (4).csv"                     
## [18] "Diamond (5).csv"                     
## [19] "Diamond (6).csv"                     
## [20] "Diamond (7).csv"                     
## [21] "Diamond (8).csv"                     
## [22] "Diamond.csv"                         
## [23] "Hdma.csv"                            
## [24] "Hedonic.csv"                         
## [25] "pgd.csv"                             
## [26] "protein.csv"                         
## [27] "RidingMowers.csv"                    
## [28] "sales-of-shampoo-over-a-three-ye.csv"
## [29] "telecom.csv"
library(data.table)

fraud=fread("ccFraud.csv")
## 
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Read 98.4% of 10000000 rows
Read 10000000 rows and 9 (of 9) columns from 0.272 GB file in 00:00:16
attach(fraud)

table(gender,fraudRisk)
##       fraudRisk
## gender       0       1
##      1 5853053  325178
##      2 3550933  270836
fraud[,sum(fraudRisk),gender]
##    gender     V1
## 1:      1 325178
## 2:      2 270836