1 Delete or Remove Columns in R

Using the dataframe below:

dtf = data.frame(Player = c("Dave", "Yiv", "Rao", "Tio"),
                 Group = c("A", "A", "B", "C"),
                 Status = c("Y", "Y", "N", "Y"),
                 Age = c(18, 19, 17, 19),
                 Score = c(15, 18, 14, 16))
dtf

  Player Group Status Age Score
1   Dave     A      Y  18    15
2    Yiv     A      Y  19    18
3    Rao     B      N  17    14
4    Tio     C      Y  19    16

Delete or remove columns by name:

# Remove the Age column
dtf1 = subset(dtf, select = - Age)
dtf1

  Player Group Status Score
1   Dave     A      Y    15
2    Yiv     A      Y    18
3    Rao     B      N    14
4    Tio     C      Y    16

# Remove the Status and Age columns
dtf2 = subset(dtf, select = - c(Status, Age))
dtf2

  Player Group Score
1   Dave     A    15
2    Yiv     A    18
3    Rao     B    14
4    Tio     C    16

Or alternatively, delete or remove columns by column numbers:

# Remove the Age column
dtf1 = dtf[, -4]
dtf1

  Player Group Status Score
1   Dave     A      Y    15
2    Yiv     A      Y    18
3    Rao     B      N    14
4    Tio     C      Y    16

# Remove the Status and Age columns
dtf2 = dtf[, - c(3, 4)] # or dtf2 = dtf[, -3:4]
dtf2

  Player Group Score
1   Dave     A    15
2    Yiv     A    18
3    Rao     B    14
4    Tio     C    16

2 Delete or Remove Rows in R

See dtf above.

Delete some rows by value:

# Remove "Status = N" row
dtf1 = subset(dtf, Status != "N") # != means "not equal to"
dtf1

  Player Group Status Age Score
1   Dave     A      Y  18    15
2    Yiv     A      Y  19    18
4    Tio     C      Y  19    16

# Remove "Status = N" or "Group = C" rows
dtf2 = subset(dtf, Status != "N" & Group != "C")
dtf2

  Player Group Status Age Score
1   Dave     A      Y  18    15
2    Yiv     A      Y  19    18

Or alternatively, delete or remove rows by row numbers:

# Remove "Status = N" row
dtf1 = dtf[-3, ]
dtf1

  Player Group Status Age Score
1   Dave     A      Y  18    15
2    Yiv     A      Y  19    18
4    Tio     C      Y  19    16

# Remove "Status = N" or "Group = C" rows
dtf2 = dtf[-3:-4, ] # or dtf2 = dtf[-c(3, 4), ]
dtf2

  Player Group Status Age Score
1   Dave     A      Y  18    15
2    Yiv     A      Y  19    18

3 Set or Reset Columns and Row Names in R

See dtf above.

dtf1 = dtf
dtf1

  Player Group Status Age Score
1   Dave     A      Y  18    15
2    Yiv     A      Y  19    18
3    Rao     B      N  17    14
4    Tio     C      Y  19    16

Set or reset column names:

colnames(dtf1) = c("Name", "Class", "New?", "Age", "Points")
dtf1

  Name Class New? Age Points
1 Dave     A    Y  18     15
2  Yiv     A    Y  19     18
3  Rao     B    N  17     14
4  Tio     C    Y  19     16

Set or reset row names:

rownames(dtf1) = c("Player 1", "Player 2", "Player 3", "Player 4")
dtf1

         Name Class New? Age Points
Player 1 Dave     A    Y  18     15
Player 2  Yiv     A    Y  19     18
Player 3  Rao     B    N  17     14
Player 4  Tio     C    Y  19     16