R Programming: Count the Number of NA values in a Data Frame column

R programming: Data frame Exercise-23 with Solution

Write a R program to count the number of NA values in a data frame column.

Sample Solution:

R Programming Code:

# Create a data frame named 'exam_data' with columns 'name', 'score', 'attempts', and 'qualify'
exam_data = data.frame(
  name = c('Anastasia', 'Dima', 'Katherine', 'James', 'Emily', 'Michael', 'Matthew', 'Laura', 'Kevin', 'Jonas'),  # Column with names
  score = c(12.5, 9, 16.5, 12, 9, 20, 14.5, 13.5, 8, 19),  # Column with scores
  attempts = c(1, NA, 2, NA, 2, NA, 1, NA, 2, 1),  # Column with attempts, including some NA values
  qualify = c('yes', 'no', 'yes', 'no', 'no', 'yes', 'yes', 'no', 'no', 'yes')  # Column with qualification status
)

# Print the message indicating that the following output is the original dataframe
print("Original dataframe:")

# Print the content of the 'exam_data' data frame
print(exam_data)

# Print the message indicating that the following output shows the number of NA values in the 'attempts' column
print("The number of NA values in attempts column:")

# Calculate and print the number of NA values in the 'attempts' column of the 'exam_data' data frame
print(sum(is.na(exam_data$attempts)))

Output:

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

Explanation:

• Create a Data Frame:
• exam_data = data.frame(...)
• Creates a data frame named exam_data with four columns: name, score, attempts, and qualify.
• The name column contains names of individuals.
• The score column contains numerical scores.
• The attempts column contains numerical values and some NA (missing values).
• The qualify column contains qualification status as 'yes' or 'no'.
• Print Original Data Frame:
• print("Original dataframe:")
• Prints the message "Original dataframe:" to indicate that the following output is the original data frame.
• print(exam_data)
• Prints the exam_data data frame to the console.
• Print Number of NA Values:
• print("The number of NA values in attempts column:")
• Prints the message "The number of NA values in attempts column:" to indicate that the following output is the count of NA values in the attempts column.
• print(sum(is.na(exam_data$attempts)))
• is.na(exam_data$attempts) creates a logical vector identifying NA values in the attempts column.
• sum(...) calculates the total number of NA values.
• print(...) prints the count of NA values to the console.

R Programming Code Editor:





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