1. The elapsed time may be ________ than the user time if your machine has multiple cores/processors
Correct Answer is : Error
2. Parallel processing is done via __________ package can make the elapsed time smaller than the user time.
Correct Answer is : Error
3. You can time ________ expressions by wrapping them in curly braces within the call to system.time().
Correct Answer is : Error
4. The profiler can be turned off by passing _________ to Rprof().
Correct Answer is : Hello World
5. How many methods exist for normalizing the data ?
Correct Answer is : Nothing
6. _______ divides the time spend in each function by the total run time
7. Which of the following function actually fits the linear model ?
8. The final bit of output that summaryRprof() provides is the ______ interval and the total runtime.
Correct Answer is : Nothing
9. Which of the following statement gives sampling interval ?
10. Which of the following code is not profiled ?
11. The ________ function takes an arbitrary number of arguments and concatenates them one by one into character strings.
12. What would be the result of following code ?
> x <- 1:3
> y <- 10:12
> rbind(x, y)
13. What would the following code print ?
> x <- list(1, "a", TRUE, 1 + 4i)
> x
Correct Answer is : Error
14. Which of the following is valid assignment?
15. What would be the output of the following code ?
> x <- vector("list", length = 5)
> x
16. What would be the output of the following code ?
> x <- factor(c("yes", "yes", "no", "yes", "no"))
> table(x)
Correct Answer is : $looser
17. Which of the following code snippet will create a vector with NAs in it ?
18. .What would the following code print ?
> x <- c(1, 2, NaN, NA, 4)
> is.na(x)
19. Which of the following would print the following output ?
foo bar
1 1 TRUE
2 2 TRUE
3 3 FALSE
4 4 FALSE
20. Data frames can be converted to a matrix by calling data._______