Page 248 - Data Science class 11
P. 248
18. Which of the following is an example of a vectorized operation as far as subtraction is concerned?
> x <- 1:4
> y <- 6:9
a. x+y b. x-y
c. x/y d. x*y
19. What would be the output of the following code?
> x <- 1:4
> y <- 6:9
> z <- x + y
> z
a. 7 9 11 13 b. 7 9 11 13 14
c. 9 11 13 d. Null
20. What would be the output of the following code?
> x <- 1:4
> x > 2
a. FALSE FALSE TRUE TRUE b. 1 2 3 4
c. 1 2 3 4 5 d. None of these
21. What would be the value of the following expression?
log(-1)
a. Warning in log(-1): NaNs produced b. 1
c. Null d. 1/10
22. What will be the output of the following code?
> g <- function(x) {
+ a <- 3
+ x+a+y
+ ## ‘y’ is a free variable
+ }
> g(2)
a. 8 b. 9
c. 42 d. Error
B. Fill in the blanks.
1. A ________________ data type is the most common type in R, and contains any number with or without a decimal.
2. ________________ vectors are sometimes called recursive vectors because they can contain other lists.
3. When a person writes more than one value in R, it is called a ________________ vector.
4. The return type is determined by the highest type of the components in the hierarchy expression: > list > ________________
> ________________ > double > integer > logical > raw > NULL.
5. A ________________ is a table or a two-dimensional array-like structure in which each column contains values of one
variable and each row contains one set of values from each column.
246 Touchpad Data Science-XI

