v1 = c(49, 80, 79, 41, 41, 52, 28, 8, 76, 8)
v2 = c(95, 46, 3, 100, 1, 59, 65, 82, 17, 20)
v3 = c(32, 96, 48, 96, 61, 54, 36, 18, 73, 67)
v4 = c(11, 56, 96, 48, 47, 84, 5, 84, 47, 16)
v5 = c(21, 41, 73, 47, 6, 20, 69, 77, 26, 79)
v6 = c(3, 46, 90, 42, 89, 48, 78, 82, 16, 65)
gender = c('F', 'F', 'M', 'F', 'M', 'M', 'F', 'M', 'M', 'F')
age = c(82, 2, 64, 93, 28, 28, 71, 68, 46, 1)
mydata <- data.frame(v1, v2, v3, v4, v5, v6, gender, age)
| v1 | v2 | v3 | v4 | v5 | v6 | gender | age |
|---|---|---|---|---|---|---|---|
| 49 | 95 | 32 | 11 | 21 | 3 | F | 82 |
| 80 | 46 | 96 | 56 | 41 | 46 | F | 2 |
| 79 | 3 | 48 | 96 | 73 | 90 | M | 64 |
| 41 | 100 | 96 | 48 | 47 | 42 | F | 93 |
| 41 | 1 | 61 | 47 | 6 | 89 | M | 28 |
| 52 | 59 | 54 | 84 | 20 | 48 | M | 28 |
| 28 | 65 | 36 | 5 | 69 | 78 | F | 71 |
| 8 | 82 | 18 | 84 | 77 | 82 | M | 68 |
| 76 | 17 | 73 | 47 | 26 | 16 | M | 46 |
| 8 | 20 | 67 | 16 | 79 | 65 | F | 1 |
myvars <- c("v1", "v2", "v3")
newdata <- mydata[myvars]
datakeep <- mydata
| v1 | v2 | v3 |
|---|---|---|
| 49 | 95 | 32 |
| 80 | 46 | 96 |
| 79 | 3 | 48 |
| 41 | 100 | 96 |
| 41 | 1 | 61 |
| 52 | 59 | 54 |
| 28 | 65 | 36 |
| 8 | 82 | 18 |
| 76 | 17 | 73 |
| 8 | 20 | 67 |
newdata1 <- mydata[!names(mydata) %in% myvars]
| v4 | v5 | v6 | gender | age |
|---|---|---|---|---|
| 11 | 21 | 3 | F | 82 |
| 56 | 41 | 46 | F | 2 |
| 96 | 73 | 90 | M | 64 |
| 48 | 47 | 42 | F | 93 |
| 47 | 6 | 89 | M | 28 |
| 84 | 20 | 48 | M | 28 |
| 5 | 69 | 78 | F | 71 |
| 84 | 77 | 82 | M | 68 |
| 47 | 26 | 16 | M | 46 |
| 16 | 79 | 65 | F | 1 |
newdata2 <- mydata[c(-3, -5)]
| v1 | v2 | v4 | v6 | gender | age |
|---|---|---|---|---|---|
| 49 | 95 | 11 | 3 | F | 82 |
| 80 | 46 | 56 | 46 | F | 2 |
| 79 | 3 | 96 | 90 | M | 64 |
| 41 | 100 | 48 | 42 | F | 93 |
| 41 | 1 | 47 | 89 | M | 28 |
| 52 | 59 | 84 | 48 | M | 28 |
| 28 | 65 | 5 | 78 | F | 71 |
| 8 | 82 | 84 | 82 | M | 68 |
| 76 | 17 | 47 | 16 | M | 46 |
| 8 | 20 | 16 | 65 | F | 1 |
mydata[3] <- mydata[5]<- NULL
| v1 | v2 | v4 | v6 | gender | age |
|---|---|---|---|---|---|
| 49 | 95 | 11 | 3 | F | 82 |
| 80 | 46 | 56 | 46 | F | 2 |
| 79 | 3 | 96 | 90 | M | 64 |
| 41 | 100 | 48 | 42 | F | 93 |
| 41 | 1 | 47 | 89 | M | 28 |
| 52 | 59 | 84 | 48 | M | 28 |
| 28 | 65 | 5 | 78 | F | 71 |
| 8 | 82 | 84 | 82 | M | 68 |
| 76 | 17 | 47 | 16 | M | 46 |
| 8 | 20 | 16 | 65 | F | 1 |
| v1 | v2 | v4 | v6 | gender | age |
|---|---|---|---|---|---|
| 49 | 95 | 11 | 3 | F | 82 |
| 80 | 46 | 56 | 46 | F | 2 |
| 79 | 3 | 96 | 90 | M | 64 |
| 41 | 100 | 48 | 42 | F | 93 |
| 41 | 1 | 47 | 89 | M | 28 |
| v1 | v2 | v4 | v6 | gender | age | |
|---|---|---|---|---|---|---|
| 1 | 49 | 95 | 11 | 3 | F | 82 |
| 4 | 41 | 100 | 48 | 42 | F | 93 |
| 7 | 28 | 65 | 5 | 78 | F | 71 |
df <- read.csv(file="marks1.csv", head=TRUE, sep=",")
| X | X.1 | test | asgn | Prsnt | Final | q1 | q2 | q3 | q4 |
|---|---|---|---|---|---|---|---|---|---|
| 60001 | Ahmad | 15 | 14 | 17 | 13 | 0.0 | 9 | 2 | 4.0 |
| 60003 | Abu | 26 | 13 | 18 | 22 | 3.0 | 5 | 8 | 6.0 |
| 60006 | Samy | 21 | 15 | 19 | 25 | 6.0 | 7 | 4 | 8.0 |
| 60008 | Chong | 25 | 10 | 17 | 14 | 2.0 | 3 | 4 | 5.0 |
| 60009 | Paul | 25 | 15 | 16 | 20 | 3.0 | 7 | 6 | 4.0 |
| 60011 | John | 18 | 15 | 19 | 22 | 4.0 | 7 | 4 | 7.0 |
| 60014 | Devi | 30 | 15 | 19 | 28 | 4.0 | 5 | 9 | 10.0 |
| 60015 | Pillip | 16 | 15 | 19 | 20 | 4.0 | 5 | 6 | 5.0 |
| 60023 | Meilin | 18 | 13 | 18 | 22 | 2.0 | 5 | 7 | 8.0 |
| 60025 | Lily | 30 | 14 | 18 | 24 | 5.5 | 6 | 5 | 7.5 |
| 60026 | Jamil | 12 | 10 | 12 | 12 | 1.0 | 5 | 1 | 6.0 |
dim(df)
## [1] 11 10
str(df)
## 'data.frame': 11 obs. of 10 variables:
## $ X : int 60001 60003 60006 60008 60009 60011 60014 60015 60023 60025 ...
## $ X.1 : chr "Ahmad" "Abu" "Samy" "Chong" ...
## $ test : int 15 26 21 25 25 18 30 16 18 30 ...
## $ asgn : int 14 13 15 10 15 15 15 15 13 14 ...
## $ Prsnt: int 17 18 19 17 16 19 19 19 18 18 ...
## $ Final: int 13 22 25 14 20 22 28 20 22 24 ...
## $ q1 : num 0 3 6 2 3 4 4 4 2 5.5 ...
## $ q2 : int 9 5 7 3 7 7 5 5 5 6 ...
## $ q3 : int 2 8 4 4 6 4 9 6 7 5 ...
## $ q4 : num 4 6 8 5 4 7 10 5 8 7.5 ...
summary(df)
## 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
colnames(df)
## [1] "X" "X.1" "test" "asgn" "Prsnt" "Final" "q1" "q2" "q3"
## [10] "q4"
names(df)[1] <- "ID"
names(df)[2] <- "StuName"
| ID | StuName | test | asgn | Prsnt | Final | q1 | q2 | q3 | q4 |
|---|---|---|---|---|---|---|---|---|---|
| 60001 | Ahmad | 15 | 14 | 17 | 13 | 0.0 | 9 | 2 | 4.0 |
| 60003 | Abu | 26 | 13 | 18 | 22 | 3.0 | 5 | 8 | 6.0 |
| 60006 | Samy | 21 | 15 | 19 | 25 | 6.0 | 7 | 4 | 8.0 |
| 60008 | Chong | 25 | 10 | 17 | 14 | 2.0 | 3 | 4 | 5.0 |
| 60009 | Paul | 25 | 15 | 16 | 20 | 3.0 | 7 | 6 | 4.0 |
| 60011 | John | 18 | 15 | 19 | 22 | 4.0 | 7 | 4 | 7.0 |
| 60014 | Devi | 30 | 15 | 19 | 28 | 4.0 | 5 | 9 | 10.0 |
| 60015 | Pillip | 16 | 15 | 19 | 20 | 4.0 | 5 | 6 | 5.0 |
| 60023 | Meilin | 18 | 13 | 18 | 22 | 2.0 | 5 | 7 | 8.0 |
| 60025 | Lily | 30 | 14 | 18 | 24 | 5.5 | 6 | 5 | 7.5 |
| 60026 | Jamil | 12 | 10 | 12 | 12 | 1.0 | 5 | 1 | 6.0 |
df[1] <- df[2] <- NULL
Total <- apply(df, 1, sum)
df<-cbind(df, Total)
| test | asgn | Prsnt | Final | q1 | q2 | q3 | q4 | Total |
|---|---|---|---|---|---|---|---|---|
| 15 | 14 | 17 | 13 | 0.0 | 9 | 2 | 4.0 | 74 |
| 26 | 13 | 18 | 22 | 3.0 | 5 | 8 | 6.0 | 101 |
| 21 | 15 | 19 | 25 | 6.0 | 7 | 4 | 8.0 | 105 |
| 25 | 10 | 17 | 14 | 2.0 | 3 | 4 | 5.0 | 80 |
| 25 | 15 | 16 | 20 | 3.0 | 7 | 6 | 4.0 | 96 |
| 18 | 15 | 19 | 22 | 4.0 | 7 | 4 | 7.0 | 96 |
| 30 | 15 | 19 | 28 | 4.0 | 5 | 9 | 10.0 | 120 |
| 16 | 15 | 19 | 20 | 4.0 | 5 | 6 | 5.0 | 90 |
| 18 | 13 | 18 | 22 | 2.0 | 5 | 7 | 8.0 | 93 |
| 30 | 14 | 18 | 24 | 5.5 | 6 | 5 | 7.5 | 110 |
| 12 | 10 | 12 | 12 | 1.0 | 5 | 1 | 6.0 | 59 |