R Programming: Extract first two Rows from a Data Frame
Write a R program to extract first two rows from a given data frame.
Sample Solution :
R Programming Code :
# Create a data frame named 'exam_data' with columns 'name', 'score', 'attempts', and 'qualify'
exam_data = data.frame(
# Define the 'name' column with a vector of student names
name = c('Anastasia', 'Dima', 'Katherine', 'James', 'Emily', 'Michael', 'Matthew', 'Laura', 'Kevin', 'Jonas'),
# Define the 'score' column with a vector of scores corresponding to the names
score = c(12.5, 9, 16.5, 12, 9, 20, 14.5, 13.5, 8, 19),
# Define the 'attempts' column with a vector of the number of attempts each student made
attempts = c(1, 3, 2, 3, 2, 3, 1, 1, 2, 1),
# Define the 'qualify' column with a vector indicating whether each student qualified
qualify = c('yes', 'no', 'yes', 'no', 'no', 'yes', 'yes', 'no', 'no', 'yes')
)
# Print a message indicating that the following output is the original data frame
print("Original dataframe:")
# Print the 'exam_data' data frame to display its contents
print(exam_data)
# Print a message indicating that the following output will show the first two rows
print("Extract first two rows:")
# Extract the first two rows of the 'exam_data' data frame and store them in a new data frame named 'result'
result = exam_data[1:2,]
# Print the 'result' data frame to display the extracted rows
print(result)
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 [1] "Extract first two rows:" name score attempts qualify 1 Anastasia 12.5 1 yes 2 Dima 9.0 3 no
Explanation:
- Creates a data frame named exam_data with four columns: name, score, attempts, and qualify. Each column contains a vector of values corresponding to students' names, their scores, the number of attempts, and whether they qualified, respectively.
- Prints the message "Original dataframe:" to indicate the following output. Then prints the exam_data data frame to display its content.
- Extracts the first two rows of the exam_data data frame and stores them in a new data frame named result. Prints the message "Extract first two rows:" followed by the result data frame to show only the first two rows of the original data frame.
R Programming Code Editor:
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