#Question #1
stdMark <- read.csv(file='C:\\Users\\aziah\\Documents\\RProject\\Week5\\marks1.csv')
print(stdMark)
## X 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 #2
(stdMark1 <- stdMark[, c(1, 2, 6)])
## X X.1 Final
## 1 60001 Ahmad 13
## 2 60003 Abu 22
## 3 60006 Samy 25
## 4 60008 Chong 14
## 5 60009 Paul 20
## 6 60011 John 22
## 7 60014 Devi 28
## 8 60015 Pillip 20
## 9 60023 Meilin 22
## 10 60025 Lily 24
## 11 60026 Jamil 12
(stdMark2 <- stdMark[, 2:5])
## X.1 test asgn Prsnt
## 1 Ahmad 15 14 17
## 2 Abu 26 13 18
## 3 Samy 21 15 19
## 4 Chong 25 10 17
## 5 Paul 25 15 16
## 6 John 18 15 19
## 7 Devi 30 15 19
## 8 Pillip 16 15 19
## 9 Meilin 18 13 18
## 10 Lily 30 14 18
## 11 Jamil 12 10 12
(stdMark3 <- stdMark[stdMark$asgn == 15, ])
## X X.1 test asgn Prsnt Final q1 q2 q3 q4
## 3 60006 Samy 21 15 19 25 6 7 4 8
## 5 60009 Paul 25 15 16 20 3 7 6 4
## 6 60011 John 18 15 19 22 4 7 4 7
## 7 60014 Devi 30 15 19 28 4 5 9 10
## 8 60015 Pillip 16 15 19 20 4 5 6 5
(stdMark4 <- stdMark[stdMark$X %in% c(60003, 60008, 60015, 60026), ] )
## X X.1 test asgn Prsnt Final q1 q2 q3 q4
## 2 60003 Abu 26 13 18 22 3 5 8 6
## 4 60008 Chong 25 10 17 14 2 3 4 5
## 8 60015 Pillip 16 15 19 20 4 5 6 5
## 11 60026 Jamil 12 10 12 12 1 5 1 6
(stdMark5 <- stdMark[with(stdMark, asgn == 15 & Final == 20), ])
## X X.1 test asgn Prsnt Final q1 q2 q3 q4
## 5 60009 Paul 25 15 16 20 3 7 6 4
## 8 60015 Pillip 16 15 19 20 4 5 6 5
#Question #3
names(stdMark)
## [1] "X" "X.1" "test" "asgn" "Prsnt" "Final" "q1" "q2" "q3"
## [10] "q4"
#Question #4
names(stdMark) <- c("ID", "X.1", "test", "asgn", "Prsnt", "Final", "q1", "q2", "q3", "q4")
print(stdMark)
## 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
names(stdMark) <- c("ID", "StuName", "test", "asgn", "Prsnt", "Final", "q1", "q2", "q3", "q4")
print(stdMark)
## 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
stdMark6 <- stdMark[c(-1,-2)]
print(stdMark6)
## test asgn Prsnt Final q1 q2 q3 q4
## 1 15 14 17 13 0.0 9 2 4.0
## 2 26 13 18 22 3.0 5 8 6.0
## 3 21 15 19 25 6.0 7 4 8.0
## 4 25 10 17 14 2.0 3 4 5.0
## 5 25 15 16 20 3.0 7 6 4.0
## 6 18 15 19 22 4.0 7 4 7.0
## 7 30 15 19 28 4.0 5 9 10.0
## 8 16 15 19 20 4.0 5 6 5.0
## 9 18 13 18 22 2.0 5 7 8.0
## 10 30 14 18 24 5.5 6 5 7.5
## 11 12 10 12 12 1.0 5 1 6.0
#Question #7
stdMark$total <- apply(stdMark[,c('test', 'asgn', 'Prsnt', 'Final', 'q1', 'q2', 'q3', 'q4')], 1, function(x) sum(x))
print(stdMark)
## ID StuName test asgn Prsnt Final q1 q2 q3 q4 total
## 1 60001 Ahmad 15 14 17 13 0.0 9 2 4.0 74
## 2 60003 Abu 26 13 18 22 3.0 5 8 6.0 101
## 3 60006 Samy 21 15 19 25 6.0 7 4 8.0 105
## 4 60008 Chong 25 10 17 14 2.0 3 4 5.0 80
## 5 60009 Paul 25 15 16 20 3.0 7 6 4.0 96
## 6 60011 John 18 15 19 22 4.0 7 4 7.0 96
## 7 60014 Devi 30 15 19 28 4.0 5 9 10.0 120
## 8 60015 Pillip 16 15 19 20 4.0 5 6 5.0 90
## 9 60023 Meilin 18 13 18 22 2.0 5 7 8.0 93
## 10 60025 Lily 30 14 18 24 5.5 6 5 7.5 110
## 11 60026 Jamil 12 10 12 12 1.0 5 1 6.0 59
#Question #8
stdMark$cw <- apply(stdMark[,c('test', 'asgn', 'Prsnt')], 1, function(x) {x[1]+x[2]+x[3]})
print(stdMark)
## ID StuName test asgn Prsnt Final q1 q2 q3 q4 total cw
## 1 60001 Ahmad 15 14 17 13 0.0 9 2 4.0 74 46
## 2 60003 Abu 26 13 18 22 3.0 5 8 6.0 101 57
## 3 60006 Samy 21 15 19 25 6.0 7 4 8.0 105 55
## 4 60008 Chong 25 10 17 14 2.0 3 4 5.0 80 52
## 5 60009 Paul 25 15 16 20 3.0 7 6 4.0 96 56
## 6 60011 John 18 15 19 22 4.0 7 4 7.0 96 52
## 7 60014 Devi 30 15 19 28 4.0 5 9 10.0 120 64
## 8 60015 Pillip 16 15 19 20 4.0 5 6 5.0 90 50
## 9 60023 Meilin 18 13 18 22 2.0 5 7 8.0 93 49
## 10 60025 Lily 30 14 18 24 5.5 6 5 7.5 110 62
## 11 60026 Jamil 12 10 12 12 1.0 5 1 6.0 59 34