Top 30 R Programming Practice Exercises for Beginners with Solutions

21. Create a matrix and calculate the row-wise and column-wise sums.

Required Input:

Matrix: 
 [,1] [,2]
[1,] 1 2
[2,] 3 4
[3,] 5 6

Expected Output:

Row-wise sums: 3 7 11 
Column-wise sums: 9 12

Code In R

# Predefined structure matrix <- matrix(c(1, 2, 3, 4, 5, 6), nrow = 3, byrow = TRUE) row_sums <- rowSums(matrix) col_sums <- colSums(matrix) print(paste("Row-wise sums:", paste(row_sums, collapse = " "))) print(paste("Column-wise sums:", paste(col_sums, collapse = " ")))

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22. Write an R program to check if a given vector contains a specific element.

Required Input:

Vector: c(1, 2, 3, 4, 5)
Element: 3

Expected Output:

Element 3 is present in the vector

Code In R

# Predefined structure vector <- c(1, 2, 3, 4, 5) element <- 3 if (element %in% vector) { print(paste("Element", element, "is present in the vector"))} else { print(paste("Element", element, "is not present in the vector"))}

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23. Create a vector and calculate the standard deviation of its elements.

Required Input:

Vector: [10, 20, 30, 40, 50]

Expected Output:

Standard Deviation: 15.81

Code In R

# Predefined structure vector <- c(10, 20, 30, 40, 50) std_dev <- sd(vector) print(paste("Standard Deviation:", round(std_dev, 2)))

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24. Write an R program to merge two data frames by a common column.

Required Input:

Data Frame 1: 
 ID Name
1 1 John
2 2 Alice
3 3 Bob
Data Frame 2: 
 ID Age
1 1 25
2 2 30
3 3 22

Expected Output:

  ID  Name Age
1  1  John  25
2  2 Alice  30
3  3   Bob  22

Code In R

# Predefined structure df1 <- data.frame(ID = c(1, 2, 3), Name = c("John", "Alice", "Bob")) df2 <- data.frame(ID = c(1, 2, 3), Age = c(25, 30, 22)) merged_df <- merge(df1, df2, by = "ID") print(merged_df)

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25. Write an R program to replace all negative numbers in a vector with zeros.

Required Input:

Vector: c(-5, 3, -2, 7, -1)

Expected Output:

[1] 0 3 0 7 0

Code In R

# Predefined structure vector <- c(-5, 3, -2, 7, -1) vector[vector < 0] <- 0 print(vector)

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26. Create a named list with three elements: a vector, a matrix, and a data frame. Access one element by its name.

Required Input:

None

Expected Output:

$vector
[1] 1 2 3

Accessed element: 
[1] 1 2 3

Code In R

# Predefined structure named_list <- list(vector = c(1, 2, 3), matrix = matrix(1:4, nrow = 2), data_frame = data.frame(Name = c("Alice", "Bob"), Age = c(25, 30))) print(named_list$vector)

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27. Write an R program to find the correlation between two numeric vectors.

Required Input:

Vector 1: c(1, 2, 3, 4, 5)
Vector 2: c(2, 4, 6, 8, 10)

Expected Output:

Correlation: 1

Code In R

# Predefined structure vector1 <- c(1, 2, 3, 4, 5) vector2 <- c(2, 4, 6, 8, 10) correlation <- cor(vector1, vector2) print(paste("Correlation:", correlation))

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