R interview questions part 15
R interview questions part 15
Take as many assements as you can to improve your validate your skill rating
Total Questions: 20
1. Which of the following functions is typically used to add elements to a plot in the base graphics system?
Correct Answer is : boxplot()
2. Which function opens the screen graphics device for the Mac ?
Correct Answer is : quartz()
3. What does the ‘pch’ option to par() control?
Correct Answer is : the plotting symbol/character in the base graphics system
4. If I want to save a plot to a PDF file, which of the following is a correct way of doing that?
Correct Answer is : Construct the plot on the screen device and then copy it to a PDF file with dev.copy2pdf()
5. __________ produces box-and-whisker plots.
Correct Answer is : bwplot
6. __________ produces bivariate scatterplots or time-series plots.
Correct Answer is : xyplot
7. Annotation of plots in any plotting system involves adding points, lines, or text to the plot, in addition to customizing axis labels or adding titles. Different plotting systems have different sets of functions for annotating plots in this way. Which of the following functions can be used to annotate the panels in a multi-panel lattice plot?
Correct Answer is : panel.abline()
8. ____________ produces one-dimensional scatterplots.
Correct Answer is : stripplot
9. which of the following functions can be used to finely control the appearance of all lattice plots ?
Correct Answer is : trellis.par.set()
10. What is ggplot2 an implementation of ?
Correct Answer is : the Grammar of Graphics developed by Leland Wilkinson
11. For barchart and _________, non-trivial methods exist for tables and arrays, documented at barchart.table.
Correct Answer is : dotplot
12. What is a geom in the ggplot2 system ?
Correct Answer is : a plotting object like point, line, or other shape
13. Logical flag is applicable to which of the following plots ?
Correct Answer is : dotplot
14. ___________ is used to determine what is plotted for each group.
Correct Answer is : panel.superpose
15. Which of the following is apply function in R ?
Correct Answer is : tapply()
16. Point out the correct statement :
Correct Answer is : All of the mentioned
17. Functions are defined using the _________ directive and are stored as R objects
Correct Answer is : function()
18. What will be the output of the following code ? > f <- function() { + ## This is an empty function + } > f()
Correct Answer is :
19. Point out the wrong statement :
Correct Answer is : Functions in R are “second class objects”
20. What will be the output of the following code ? > f <- function() { + ## This is an empty function + } > class(f)
Correct Answer is : “function”
