R Language Interview Questions and Answers
Intermediate / 1 to 5 years experienced level questions & answers
Ques 1. Explain the use of the 'apply()' function in R.
The apply() function is used to apply a function to the rows or columns of a matrix or array.
Example:
apply(matrix, 1, sum)
Ques 2. What is the purpose of the 'merge()' function in R?
The merge() function is used to merge two or more data frames based on a common column.
Example:
merged_data <- merge(df1, df2, by='common_column')
Ques 3. Explain the concept of factor variables in R.
Factor variables are used to represent categorical data in R. They can have levels, which represent the categories.
Example:
gender <- factor(c('Male', 'Female', 'Male'), levels=c('Male', 'Female'))
Ques 4. How do you handle missing values in a data frame in R?
You can use the na.omit() function to remove rows with missing values, or use functions like is.na() to identify missing values.
Example:
cleaned_data <- na.omit(df)
Ques 5. Explain the purpose of the 'dplyr' package in R.
The 'dplyr' package provides a grammar of data manipulation, with functions like filter(), select(), and mutate(), making data manipulation tasks more intuitive.
Example:
library(dplyr)
filtered_data <- filter(df, Age > 25)
Ques 6. Explain the purpose of the 'purrr' package in R.
'purrr' is a package in R that enhances functional programming with a consistent and concise syntax, making it easier to work with lists and vectors.
Example:
library(purrr)
map(my_list, my_function)
Ques 7. What is the purpose of the 'reshape2' package in R?
'reshape2' is a package used for reshaping data frames. It provides functions like melt() and cast() for converting between wide and long formats.
Example:
library(reshape2)
melted_data <- melt(my_data, id.vars=c('id', 'name'))
Ques 8. How do you handle exceptions in R?
You can use the 'tryCatch()' function to handle exceptions in R. It allows you to define code to be executed in case an error occurs.
Example:
tryCatch({
# code that might cause an error
}, error = function(e) {
# code to handle the error
})
Ques 9. Explain the purpose of the 'caret' package in R.
'caret' is a package in R used for streamlining the process of applying machine learning models. It provides a unified interface for various modeling techniques.
Example:
library(caret)
model <- train(y ~ ., data = my_data, method = 'lm')
Most helpful rated by users:
Related interview subjects
| Golang interview questions and answers - Total 30 questions |
| Embedded C interview questions and answers - Total 30 questions |
| C++ interview questions and answers - Total 142 questions |
| VBA interview questions and answers - Total 30 questions |
| COBOL interview questions and answers - Total 50 questions |
| R Language interview questions and answers - Total 30 questions |
| Python Coding interview questions and answers - Total 20 questions |
| Scala interview questions and answers - Total 48 questions |
| Swift interview questions and answers - Total 49 questions |