R Language Interview Questions and Answers
Ques 16. How can you check if a variable is defined in R?
You can use the 'exists()' function to check if a variable exists in the specified environment.
Example:
exists('my_variable')
Ques 17. Explain the purpose of the 'ggplot2' package in R.
'ggplot2' is a popular data visualization package in R that allows users to create complex and customized plots with a grammar of graphics approach.
Example:
library(ggplot2)
ggplot(data = my_data, aes(x = variable1, y = variable2)) + geom_point()
Ques 18. What is the difference between 'ls()' and 'objects()' functions in R?
'ls()' and 'objects()' both list objects in the current environment, but 'ls()' is a shorthand form of 'objects()' and has additional options.
Example:
ls()
# or
objects()
Ques 19. 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 20. 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'))
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