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Interview question based on skill :

Take as many assements as you can to improve your validate your skill rating

Total Questions: 20

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

Correct Answer is : 1010

7. Which of the following function actually fits the linear model ?

Correct Answer is : 5

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 ?

Correct Answer is : 105

10. Which of the following code is not profiled ?

Correct Answer is : 439

11. The ________ function takes an arbitrary number of arguments and concatenates them one by one into character strings.

Correct Answer is : 437

12. What would be the result of following code ? > x <- 1:3 > y <- 10:12 > rbind(x, y)

Correct Answer is : 9

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?

Correct Answer is : 1400

15. What would be the output of the following code ? > x <- vector("list", length = 5) > x

Correct Answer is : /

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 ?

Correct Answer is : \

18. .What would the following code print ? > x <- c(1, 2, NaN, NA, 4) > is.na(x)

Correct Answer is : 15

19. Which of the following would print the following output ? foo bar 1 1 TRUE 2 2 TRUE 3 3 FALSE 4 4 FALSE

Correct Answer is : 10

20. Data frames can be converted to a matrix by calling data._______

Correct Answer is : 0