What function is commonly used to calculate the mean in R?
- mean()
- median()
- sum()
- mode()
The mean() function is commonly used to calculate the mean in R. The mean() function calculates the arithmetic average of a numeric vector.
An else statement in R can only be used after an ________ statement.
- if
- for
- while
- repeat
An else statement in R can only be used after an if statement. It provides an alternative code block to execute when the condition of the if statement is false. The else statement is optional and allows for branching based on the outcome of the if condition.
In R, to match a literal period in a regular expression, you would use the escape sequence ________.
- .
- *
- /
- ?
In R, to match a literal period (dot) in a regular expression, you would use the escape sequence . . For example, "abc.def" would match the string "abc.def".
How do you convert a numeric variable to a string in R?
- as.character()
- convert_to_string()
- str()
- to_string()
In R, the as.character() function is used to convert a numeric variable to a string. For example, as.character(123) would return "123".
Can variables in R hold more than one data type at a time?
- No, variables in R can hold only one data type at a time
- None of the above
- Yes, if the variable is a list
- Yes, if the variable is a vector
In R, a variable can hold more than one data type at a time if it is a list. Lists in R can contain elements of different types (e.g., numbers, strings, vectors, and other lists). However, other common R data structures, such as vectors and matrices, can hold only one data type at a time.
The ________ function in R helps to print a more human-readable version of complex objects.
- cat()
- print()
- str()
- summary()
The str() function in R provides a compact, human-readable description of any R object, making it easier to understand the structure and content of complex objects.
In R, a function that calls itself within its own definition is known as a ________ function.
- Recursive
- Nested
- Iterative
- Repeating
In R, a function that calls itself within its own definition is known as a recursive function. Recursive functions are defined in a way that allows them to break down a complex problem into smaller sub-problems of the same type, eventually reaching a base case where the recursion stops. This self-referential behavior is a key characteristic of recursive functions.
Imagine you want to concatenate a vector of numbers into a single string. What steps would you take?
- None of the above
- Use the as.character() function then the paste() function
- Use the paste() function with collapse argument
- Use the str() function then the paste() function
To concatenate a vector of numbers into a single string, you would first need to convert the numbers into characters using the 'as.character()' function. Then, you can use the 'paste()' function with the 'collapse' argument to concatenate all the elements into a single string.
The ______ function in R can be used to explode segments in a pie chart.
- explode()
- pull()
- detach()
- All of the above
The explode() function in R can be used to explode segments in a pie chart. By specifying a vector of values, the explode() function moves specific segments away from the center of the pie chart, highlighting or separating them for emphasis.
How do you perform a logical 'AND' operation in R?
- Using the '&' operator
- Using the '&&' operator
- Using the 'AND' keyword
- All of the above
In R, you can perform a logical 'AND' operation using the '&' operator. The '&' operator returns 'TRUE' if both operands are 'TRUE', and 'FALSE' otherwise. For example, 'TRUE & FALSE' would evaluate to 'FALSE'.