R Programming: Drop column(s) by Name from a Given Data Frame

R Programming: Data frame Exercise-10 with Solution

Write a R program to drop column(s) by name from a given data frame.

Sample Solution :

R Programming Code :

# Create a data frame named 'exam_data' with columns: name, score, attempts, qualify
exam_data = data.frame(
  name = c('Anastasia', 'Dima', 'Katherine', 'James', 'Emily', 'Michael', 'Matthew', 'Laura', 'Kevin', 'Jonas'), # Names of students
  score = c(12.5, 9, 16.5, 12, 9, 20, 14.5, 13.5, 8, 19), # Scores obtained by students
  attempts = c(1, 3, 2, 3, 2, 3, 1, 1, 2, 1), # Number of attempts made by students
  qualify = c('yes', 'no', 'yes', 'no', 'no', 'yes', 'yes', 'no', 'no', 'yes') # Qualification status of students
)

# Print the message "Original dataframe:"
print("Original dataframe:")

# Print the original data frame 'exam_data'
print(exam_data)

# Remove the columns 'name' and 'qualify' from 'exam_data' using subset function
exam_data = subset(exam_data, select = -c(name, qualify))

# Print the modified data frame after removing specified columns
print(exam_data)

Output:

[1] "Original dataframe:"
        name score attempts qualify
1  Anastasia  12.5        1     yes
2       Dima   9.0        3      no
3  Katherine  16.5        2     yes
4      James  12.0        3      no
5      Emily   9.0        2      no
6    Michael  20.0        3     yes
7    Matthew  14.5        1     yes
8      Laura  13.5        1      no
9      Kevin   8.0        2      no
10     Jonas  19.0        1     yes
   score attempts
1   12.5        1
2    9.0        3
3   16.5        2
4   12.0        3
5    9.0        2
6   20.0        3
7   14.5        1
8   13.5        1
9    8.0        2
10  19.0        1                      

Explanation:

• Create a data frame: A data frame named exam_data is created with four columns: name, score, attempts, and qualify.
• name: A vector of student names.
• score: A vector of scores obtained by the students.
• attempts: A vector indicating the number of attempts made by the students.
• qualify: A vector indicating the qualification status of the students (yes or no).
• Print message: Prints the message "Original dataframe:" to indicate that the original data frame will be displayed.
• Print the original data frame: Prints the exam_data data frame showing all columns (name, score, attempts, and qualify).
• Drop columns by name: Uses the subset() function to create a modified version of the exam_data data frame by removing the name and qualify columns.
• Print the modified data frame: Prints the modified exam_data data frame, which now only contains the score and attempts columns.

R Programming Code Editor:

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