HOMEWORK#1

문제

StudentNum=1:10
English=c(70,NA,80,85,90,90,60,55,NA,90)
Math=c(80,73,84,90,95,85,60,50,NA,100)
data=data.frame(StudentNum,English,Math)
data

##    StudentNum English Math
## 1           1      70   80
## 2           2      NA   73
## 3           3      80   84
## 4           4      85   90
## 5           5      90   95
## 6           6      90   85
## 7           7      60   60
## 8           8      55   50
## 9           9      NA   NA
## 10         10      90  100

위의 성적 data를 사용하여 젠제누락된 값을 각 과목의 평균치로 채워 넣으세요.

apply(data,2,function(x){ifelse(is.na(x),mean(x,na.rm=TRUE),x)})

##       StudentNum English      Math
##  [1,]          1    70.0  80.00000
##  [2,]          2    77.5  73.00000
##  [3,]          3    80.0  84.00000
##  [4,]          4    85.0  90.00000
##  [5,]          5    90.0  95.00000
##  [6,]          6    90.0  85.00000
##  [7,]          7    60.0  60.00000
##  [8,]          8    55.0  50.00000
##  [9,]          9    77.5  79.66667
## [10,]         10    90.0 100.00000