#Question 1
dataframe<-read.csv(file='marks1.csv', header = TRUE, sep=',')
#Question 2
typeof(dataframe)
## [1] "list"
class(dataframe)
## [1] "data.frame"
View(dataframe)
summary(dataframe)
## X X.1 test asgn
## Min. :60001 Length:11 Min. :12.00 Min. :10.00
## 1st Qu.:60007 Class :character 1st Qu.:17.00 1st Qu.:13.00
## Median :60011 Mode :character Median :21.00 Median :14.00
## Mean :60013 Mean :21.45 Mean :13.55
## 3rd Qu.:60019 3rd Qu.:25.50 3rd Qu.:15.00
## Max. :60026 Max. :30.00 Max. :15.00
## Prsnt Final q1 q2
## Min. :12.00 Min. :12.00 Min. :0.000 Min. :3.000
## 1st Qu.:17.00 1st Qu.:17.00 1st Qu.:2.000 1st Qu.:5.000
## Median :18.00 Median :22.00 Median :3.000 Median :5.000
## Mean :17.45 Mean :20.18 Mean :3.136 Mean :5.818
## 3rd Qu.:19.00 3rd Qu.:23.00 3rd Qu.:4.000 3rd Qu.:7.000
## Max. :19.00 Max. :28.00 Max. :6.000 Max. :9.000
## q3 q4
## Min. :1.000 Min. : 4.000
## 1st Qu.:4.000 1st Qu.: 5.000
## Median :5.000 Median : 6.000
## Mean :5.091 Mean : 6.409
## 3rd Qu.:6.500 3rd Qu.: 7.750
## Max. :9.000 Max. :10.000
#Question 3
names(dataframe)
## [1] "X" "X.1" "test" "asgn" "Prsnt" "Final" "q1" "q2" "q3"
## [10] "q4"
#Question 4
names(dataframe)[names(dataframe)=='X']<-'Id'
dataframe
## Id X.1 test asgn Prsnt Final q1 q2 q3 q4
## 1 60001 Ahmad 15 14 17 13 0.0 9 2 4.0
## 2 60003 Abu 26 13 18 22 3.0 5 8 6.0
## 3 60006 Samy 21 15 19 25 6.0 7 4 8.0
## 4 60008 Chong 25 10 17 14 2.0 3 4 5.0
## 5 60009 Paul 25 15 16 20 3.0 7 6 4.0
## 6 60011 John 18 15 19 22 4.0 7 4 7.0
## 7 60014 Devi 30 15 19 28 4.0 5 9 10.0
## 8 60015 Pillip 16 15 19 20 4.0 5 6 5.0
## 9 60023 Meilin 18 13 18 22 2.0 5 7 8.0
## 10 60025 Lily 30 14 18 24 5.5 6 5 7.5
## 11 60026 Jamil 12 10 12 12 1.0 5 1 6.0
#Question 5
colnames(dataframe)[2]<-'StuName'
dataframe
## Id StuName test asgn Prsnt Final q1 q2 q3 q4
## 1 60001 Ahmad 15 14 17 13 0.0 9 2 4.0
## 2 60003 Abu 26 13 18 22 3.0 5 8 6.0
## 3 60006 Samy 21 15 19 25 6.0 7 4 8.0
## 4 60008 Chong 25 10 17 14 2.0 3 4 5.0
## 5 60009 Paul 25 15 16 20 3.0 7 6 4.0
## 6 60011 John 18 15 19 22 4.0 7 4 7.0
## 7 60014 Devi 30 15 19 28 4.0 5 9 10.0
## 8 60015 Pillip 16 15 19 20 4.0 5 6 5.0
## 9 60023 Meilin 18 13 18 22 2.0 5 7 8.0
## 10 60025 Lily 30 14 18 24 5.5 6 5 7.5
## 11 60026 Jamil 12 10 12 12 1.0 5 1 6.0
#Question 6
dataframe$id<-dataframe$StuName<-NULL
dataframe
## Id test asgn Prsnt Final q1 q2 q3 q4
## 1 60001 15 14 17 13 0.0 9 2 4.0
## 2 60003 26 13 18 22 3.0 5 8 6.0
## 3 60006 21 15 19 25 6.0 7 4 8.0
## 4 60008 25 10 17 14 2.0 3 4 5.0
## 5 60009 25 15 16 20 3.0 7 6 4.0
## 6 60011 18 15 19 22 4.0 7 4 7.0
## 7 60014 30 15 19 28 4.0 5 9 10.0
## 8 60015 16 15 19 20 4.0 5 6 5.0
## 9 60023 18 13 18 22 2.0 5 7 8.0
## 10 60025 30 14 18 24 5.5 6 5 7.5
## 11 60026 12 10 12 12 1.0 5 1 6.0
#Question 7
dataframe$Total<-apply(dataframe[,c(3:8)],1, function(x) sum(x))
dataframe
## Id test asgn Prsnt Final q1 q2 q3 q4 Total
## 1 60001 15 14 17 13 0.0 9 2 4.0 55.0
## 2 60003 26 13 18 22 3.0 5 8 6.0 69.0
## 3 60006 21 15 19 25 6.0 7 4 8.0 76.0
## 4 60008 25 10 17 14 2.0 3 4 5.0 50.0
## 5 60009 25 15 16 20 3.0 7 6 4.0 67.0
## 6 60011 18 15 19 22 4.0 7 4 7.0 71.0
## 7 60014 30 15 19 28 4.0 5 9 10.0 80.0
## 8 60015 16 15 19 20 4.0 5 6 5.0 69.0
## 9 60023 18 13 18 22 2.0 5 7 8.0 67.0
## 10 60025 30 14 18 24 5.5 6 5 7.5 72.5
## 11 60026 12 10 12 12 1.0 5 1 6.0 41.0
#Qustion 8
dataframe$cw<-apply(dataframe[, c(3:9)], 1, function(x) {x[1]+x[2]+x[3]})
dataframe
## Id test asgn Prsnt Final q1 q2 q3 q4 Total cw
## 1 60001 15 14 17 13 0.0 9 2 4.0 55.0 44
## 2 60003 26 13 18 22 3.0 5 8 6.0 69.0 53
## 3 60006 21 15 19 25 6.0 7 4 8.0 76.0 59
## 4 60008 25 10 17 14 2.0 3 4 5.0 50.0 41
## 5 60009 25 15 16 20 3.0 7 6 4.0 67.0 51
## 6 60011 18 15 19 22 4.0 7 4 7.0 71.0 56
## 7 60014 30 15 19 28 4.0 5 9 10.0 80.0 62
## 8 60015 16 15 19 20 4.0 5 6 5.0 69.0 54
## 9 60023 18 13 18 22 2.0 5 7 8.0 67.0 53
## 10 60025 30 14 18 24 5.5 6 5 7.5 72.5 56
## 11 60026 12 10 12 12 1.0 5 1 6.0 41.0 34