85 + Interview Questions in Profiling in R Programming Page 2 InterviewSolution

51.	How many methods exist for normalizing the data?(a) one(b) two(c) three(d) profilerThe question was asked during an online exam.My question comes from R Profiler topic in section Profiling, Simulation and Data Analysis of R Programming
Answer» Right answer is (b) TWO The explanation is: There are two methods for NORMALIZING the DATA.

Discussion

52.	Parallel processing is done via __________ package can make the elapsed time smaller than the user time.(a) parallel(b) statistics(c) distributed(d) symmetryThe question was asked at a job interview.Origin of the question is R Profiler topic in section Profiling, Simulation and Data Analysis of R Programming
Answer» RIGHT choice is (a) parallel Best explanation: When you have MULTIPLE processors/- cores/machines working in parallel, the amount of time that the collection of CPUs SPENDS working on a problem is the same as with a single CPU, but because they are OPERATING in parallel, there is a savings in ELAPSED time.

Discussion

53.	_________ generate aesthetic mappings that describe how variables in the data.(a) aes_all(b) aes_auto(c) aes(d) aes_stringThis question was addressed to me in an interview.Origin of the question is ggplot2 in division Profiling, Simulation and Data Analysis of R Programming
Answer» Right OPTION is (c) aes Easiest explanation: aes generate AESTHETIC MAPPINGS that describe how variables in the DATA. aes_auto is used for AUTOMATIC aesthetic mapping.

Discussion

54.	Which of the following draws plot on current graphics device?(a) ggmissplot(b) printplot(c) print.ggplot(d) ggfluctuationThe question was asked in my homework.Asked question is from ggplot2 in chapter Profiling, Simulation and Data Analysis of R Programming
Answer» CORRECT OPTION is (c) print.ggplot The best I can explain: print.ggplot is ALSO known as plot.ggplot.

Discussion

55.	The final bit of output that summaryRprof() provides is the ______ interval and the total runtime.(a) response(b) sampling(c) processing(d) retrieveI have been asked this question in examination.My doubt stems from R Profiler in chapter Profiling, Simulation and Data Analysis of R Programming
Answer» Correct CHOICE is (b) sampling The BEST explanation: You’re going to be spending a LOT of time in preprocessing and CHECKING.

Discussion

56.	Point out the wrong statement?(a) mean_se is used to calculate mean and standard errors on either side(b) hmisc wraps up a selection of summary functions from Hmisc to make it easy to use(c) plot is used to create a scatterplot matrix (experimental)(d) translate_qplot_base is used for translating between qplot and base graphicsThis question was addressed to me by my school principal while I was bunking the class.My question is from ggplot2 in division Profiling, Simulation and Data Analysis of R Programming
Answer» Correct choice is (c) PLOT is used to create a SCATTERPLOT matrix (EXPERIMENTAL) EASY EXPLANATION: plotmatrix is used to create a scatterplot matrix (experimental).

Discussion

57.	________ is a systematic way to examine how much time is spent in different parts of a program.(a) Profiling(b) Monitoring(c) Logging(d) DebuggingThe question was posed to me in a national level competition.Query is from R Profiler topic in section Profiling, Simulation and Data Analysis of R Programming
Answer» The correct OPTION is (a) Profiling To elaborate: Sometimes profiling BECOMES necessary as a project grows and layers of CODE are placed on TOP of each other.

Discussion

58.	The _______ function computes the time (in seconds) needed to execute an expression.(a) system.timedeb()(b) system.time()(c) system.datetime()(d) system.deb()This question was posed to me in an online interview.My doubt is from R Profiler in division Profiling, Simulation and Data Analysis of R Programming
Answer» CORRECT choice is (B) system.time() Explanation: They system.time() function takes an ARBITRARY R expression as input and returns the amount of time taken to evaluate the expression.

Discussion

59.	________ generate random Normal variates with a given mean and standard deviation.(a) dnorm(b) rnorm(c) pnorm(d) rpoisThe question was posed to me by my college director while I was bunking the class.I would like to ask this question from Simulation topic in section Profiling, Simulation and Data Analysis of R Programming
Answer» The correct choice is (b) rnorm Easy explanation: The “R” FUNCTION is the ONE that ACTUALLY SIMULATES random numbers from that distribution.

Discussion

60.	_________ display contours of a 3d surface in 2d.(a) aes_contour(b) geom_contour(c) aes_gem(d) aes_autoThe question was asked at a job interview.The question is from ggplot2 topic in portion Profiling, Simulation and Data Analysis of R Programming
Answer» Correct answer is (b) geom_contour Easy explanation: A LAYER specific dataset – only NEEDED if you want to override the PLOT defaults.

Discussion

61.	__________ create a complete ggplot appropriate to a particular data type.(a) autoplot(b) is.ggplot(c) printplot(d) qplot_ggplotThis question was posed to me during an online exam.This question is from ggplot2 in portion Profiling, Simulation and Data Analysis of R Programming
Answer» Correct answer is (a) autoplot The explanation: autoplot uses ggplot2 to DRAW a particular PLOT for an object of a particular class in a SINGLE command.

Discussion

62.	The profiler can be turned off by passing _________ to Rprof().(a) 0(b) 1(c) 2(d) NULLThe question was asked during an internship interview.Enquiry is from R Profiler topic in section Profiling, Simulation and Data Analysis of R Programming
Answer» RIGHT answer is (d) NULL Explanation: RPROF(NULL) is used to turn off the profiler.

Discussion

63.	Which of the following creates fluctuation plot?(a) ggmissplot(b) ggmissing(c) ggfluctuation(d) ggpcpThe question was posed to me during an online exam.Asked question is from ggplot2 topic in portion Profiling, Simulation and Data Analysis of R Programming
Answer» Right option is (b) ggmissing To ELABORATE: FLUCTUATIONS are used to DETECT OUTLIERS.

Discussion

64.	_______ divides the time spend in each function by the total run time(a) “by.sum”(b) “by.total”(c) “by.self”(d) “by.del”This question was posed to me at a job interview.My doubt stems from R Profiler in portion Profiling, Simulation and Data Analysis of R Programming
Answer» CORRECT ANSWER is (B) “by.total” To ELABORATE: “by.self” does the same as “by.total”.

Discussion

65.	Which of the following code is not profiled?(a) C(b) C++(c) Java(d) PHPThis question was addressed to me by my school principal while I was bunking the class.Question is from R Profiler topic in portion Profiling, Simulation and Data Analysis of R Programming
Answer» RIGHT answer is (a) C Explanation: C or FORTRAN CODE is not profiled.

Discussion

66.	Which of the following function actually fits the linear model?(a) lm.time()(b) lm.date()(c) lm.fit()(d) lm.interval()This question was posed to me during an interview.I would like to ask this question from R Profiler topic in portion Profiling, Simulation and Data Analysis of R Programming
Answer» Correct option is (c) lm.fit() The best explanation: lm() function does a BIT of pre-processing and CHECKING before it ACTUALLY FITS the model.

Discussion

67.	Point out the wrong statement?(a) is.rel reports whether x is a theme object(b) is.theme reports whether x is a theme object(c) opts build a theme (or partial theme) from theme elements(d) theme_bw is theme with grey background and white gridlinesThe question was asked in an interview for internship.My doubt stems from ggplot2 topic in section Profiling, Simulation and Data Analysis of R Programming
Answer» The correct OPTION is (a) is.rel reports WHETHER X is a theme object Explanation: is.rel reports whether x is a real object.

Discussion

68.	_______ grammar makes a clear distinction between your data and what gets displayed on the screen or page.(a) ggplot1(b) ggplot2(c) d3.js(d) ggplot3I have been asked this question in homework.I'm obligated to ask this question of ggplot2 in section Profiling, Simulation and Data Analysis of R Programming
Answer» The correct answer is (b) ggplot2 For explanation I would SAY: The emphasis in ggplot2 is reducing the amount of THINKING time by MAKING it easier to GO from the plot in your brain to the plot on the PAGE.

Discussion

69.	Which of the following creates a new ggplot plot from a data frame?(a) qplot_ggplot(b) ggplot.data.frame(c) ggfluctuation(d) ggmissplotI have been asked this question in final exam.This key question is from ggplot2 topic in portion Profiling, Simulation and Data Analysis of R Programming
Answer» CORRECT ANSWER is (b) ggplot.data.frame To ELABORATE: Default list of aesthetic mappings are displayed.

Discussion

70.	You can time ________ expressions by wrapping them in curly braces within the call to system.time().(a) smaller(b) longer(c) error(d) graterThis question was addressed to me by my college director while I was bunking the class.I want to ask this question from R Profiler in section Profiling, Simulation and Data Analysis of R Programming
Answer» CORRECT option is (b) longer Explanation: If your EXPRESSION is GETTING pretty long (more than 2 or 3 lines), it might be BETTER to either break it into smaller PIECES or to use the profiler.

Discussion

71.	Point out the correct statement?(a) Rprof() is used to turn off the profiler(b) At each line of the output, the profiler writes out the function call stack(c) The summaryprof() function tabulates the R profiler output(d) The Rprofiler() function starts the profiler in RI have been asked this question in my homework.The question is from R Profiler in section Profiling, Simulation and Data Analysis of R Programming
Answer» CORRECT option is (b) At each line of the OUTPUT, the profiler writes out the function CALL stack Easiest explanation: The RPROFILER() function starts the profiler in R.

Discussion

72.	Point out the correct statement?(a) Rprofiler() tabulates how much time is spent inside each function(b) Rprof() keeps track of the function call stack at regularly sampled intervals(c) By default, the profiler samples the function call stack every 2 seconds(d) R must not be compiled with profiler supportThis question was posed to me in an interview for internship.This intriguing question comes from R Profiler topic in division Profiling, Simulation and Data Analysis of R Programming
Answer» The CORRECT answer is (b) Rprof() keeps TRACK of the FUNCTION CALL stack at regularly sampled intervals Easy explanation: The profiler is started by CALLING the Rprof() function.

Discussion

73.	Point out the correct statement?(a) autoplotgraph is used to complete ggplot appropriate to a particular data type(b) auto_element wraps up a projection of summary functions(c) ggplot.data create a new ggplot plot from a data frame(d) aes_sdensity display a smooth density estimateThis question was addressed to me in my homework.This question is from ggplot2 in chapter Profiling, Simulation and Data Analysis of R Programming
Answer» The CORRECT ANSWER is (c) ggplot.data create a new ggplot plot from a data frame Explanation: is.ggplot reports WHETHER x is a ggplot OBJECT.

Discussion

74.	__________ modifies geom/stat aesthetic defaults for future plots.(a) translate_qplot_base(b) translate_qplot_gpl(c) translate_qplot_defaults(d) translate_qplot_ggplotI got this question during an online interview.Query is from ggplot2 in division Profiling, Simulation and Data Analysis of R Programming
Answer» Correct choice is (C) translate_qplot_defaults Easy explanation: translate_qplot_gpl is used for TRANSLATING between qplot and Graphics PRODUCTION Library (GPL).

Discussion

75.	Point out the wrong statement?(a) theme_minimal is minimalistic theme with no background annotations(b) theme_color is classic-looking theme, with x and y axis lines and no gridlines(c) theme_classic is a classic-looking theme(d) translate_qplot_base is used for translating between qplot and base graphicsI have been asked this question during an internship interview.My enquiry is from ggplot2 topic in division Profiling, Simulation and Data Analysis of R Programming
Answer» RIGHT ANSWER is (b) theme_color is classic-looking THEME, with x and y AXIS LINES and no gridlines The explanation: theme_classic is a classic-looking theme, with x and y axis lines and no gridlines.

Discussion

76.	Which of the following cuts numeric vector into intervals of equal length?(a) cut_interval(b) cut_time(c) cut_number(d) cut_dateThe question was asked in an international level competition.The query is from ggplot2 in section Profiling, Simulation and Data Analysis of R Programming
Answer» Right answer is (a) cut_interval Explanation: cut_number CUTS numeric vector into INTERVALS CONTAINING EQUAL number of POINTS.

Discussion

77.	________ is used to create a plot to illustrate patterns of missing values.(a) ggmissplot(b) ggmissing(c) ggfluctuation(d) ggpcpThe question was posed to me in an interview.I'm obligated to ask this question of ggplot2 topic in chapter Profiling, Simulation and Data Analysis of R Programming
Answer» Correct answer is (B) ggmissing The best explanation: The missing values PLOT is a useful tool to GET a rapid OVERVIEW of the number and pattern of missing values in a dataset.

Discussion

78.	_________ time is time charged to the CPU(s) for the R expression.(a) elapsed(b) user(c) response(d) monitorI have been asked this question in an interview for job.I'd like to ask this question from R Profiler in division Profiling, Simulation and Data Analysis of R Programming
Answer» RIGHT option is (a) elapsed Easiest EXPLANATION: Usually, the user time and elapsed time are relatively close, for STRAIGHT COMPUTING tasks.

Discussion

79.	R comes with a ________ to help you optimize your code and improve its performance.(a) debugger(b) monitor(c) browser(d) profilerI got this question in an internship interview.I'd like to ask this question from R Profiler in division Profiling, Simulation and Data Analysis of R Programming
Answer» Right option is (a) debugger The explanation: In general, it’s usually a BAD idea to FOCUS on OPTIMIZING your CODE at the very beginning of development.

Discussion

80.	Which of the following statement gives sampling interval?(a) $sampling.interval(b) $sampling.time(c) $sampling.date(d) $sampling.datetimeI had been asked this question by my school principal while I was bunking the class.This is a very interesting question from R Profiler topic in division Profiling, Simulation and Data Analysis of R Programming
Answer» The correct ANSWER is (B) $sampling.TIME Easy explanation: Sampling time is EXPRESSED in secs.

Discussion

81.	Which of the following is a differentiation related aesthetic?(a) aes_position(b) aes_group_order(c) aes_linetype_size_shape(d) ggorderI have been asked this question in an international level competition.I need to ask this question from ggplot2 topic in portion Profiling, Simulation and Data Analysis of R Programming
Answer» RIGHT choice is (C) aes_linetype_size_shape The BEST I can explain: aes_position is POSITION related AESTHETICS.

Discussion

82.	________ is used for translating between qplot and base graphics.(a) translate_qplot_base(b) translate_qplot_gpl(c) translate_qplot_lattice(d) translate_qplot_ggplotThe question was posed to me by my school teacher while I was bunking the class.This interesting question is from ggplot2 topic in chapter Profiling, Simulation and Data Analysis of R Programming
Answer» Correct OPTION is (a) translate_qplot_base The best I can EXPLAIN: translate_qplot_gpl is used for translating between qplot and GRAPHICS PRODUCTION Library (GPL).

Discussion

83.	Point out the correct statement?(a) “by.total” first subtracts out time spent in functions above the current function in the call stack(b) The summaryRprof() function calculates how much time is spend in which function(c) By default, the profiler samples the function call stack every 0.02 seconds(d) The Rprofiler() function starts the profiler in RThis question was posed to me during an interview.This key question is from R Profiler topic in section Profiling, Simulation and Data Analysis of R Programming
Answer» The correct OPTION is (c) By default, the profiler SAMPLES the FUNCTION call STACK every 0.02 seconds For explanation I would say: Output of by.self is more USEFUL than by.total for interpreting the data.

Discussion

84.	system.time function returns an object of class _______ which contains two useful bits of information.(a) debug_time(b) proc_time(c) procedure_time(d) date.time_timeI got this question by my school principal while I was bunking the class.This intriguing question comes from R Profiler topic in division Profiling, Simulation and Data Analysis of R Programming
Answer» CORRECT option is (B) proc_time For EXPLANATION: if there’s an error, gives the TIME until the error occurred.

Discussion

85.	________ modify a ggplot or theme object by adding on new components.(a) +.gg(b) -.gg(c) /.gg(d) .ggI have been asked this question in unit test.I would like to ask this question from ggplot2 topic in chapter Profiling, Simulation and Data Analysis of R Programming
Answer» The correct answer is (a) +.gg To explain: This OPERATOR ALLOWS you to add OBJECTS to a ggplot or THEME OBJECT.

Discussion

Explore topic-wise InterviewSolutions in .

How many methods exist for normalizing the data?(a) one(b) two(c) three(d) profilerThe question was asked during an online exam.My question comes from R Profiler topic in section Profiling, Simulation and Data Analysis of R Programming

_________ generate aesthetic mappings that describe how variables in the data.(a) aes_all(b) aes_auto(c) aes(d) aes_stringThis question was addressed to me in an interview.Origin of the question is ggplot2 in division Profiling, Simulation and Data Analysis of R Programming

Which of the following draws plot on current graphics device?(a) ggmissplot(b) printplot(c) print.ggplot(d) ggfluctuationThe question was asked in my homework.Asked question is from ggplot2 in chapter Profiling, Simulation and Data Analysis of R Programming

The final bit of output that summaryRprof() provides is the ______ interval and the total runtime.(a) response(b) sampling(c) processing(d) retrieveI have been asked this question in examination.My doubt stems from R Profiler in chapter Profiling, Simulation and Data Analysis of R Programming

_________ display contours of a 3d surface in 2d.(a) aes_contour(b) geom_contour(c) aes_gem(d) aes_autoThe question was asked at a job interview.The question is from ggplot2 topic in portion Profiling, Simulation and Data Analysis of R Programming

__________ create a complete ggplot appropriate to a particular data type.(a) autoplot(b) is.ggplot(c) printplot(d) qplot_ggplotThis question was posed to me during an online exam.This question is from ggplot2 in portion Profiling, Simulation and Data Analysis of R Programming

The profiler can be turned off by passing _________ to Rprof().(a) 0(b) 1(c) 2(d) NULLThe question was asked during an internship interview.Enquiry is from R Profiler topic in section Profiling, Simulation and Data Analysis of R Programming

Which of the following creates fluctuation plot?(a) ggmissplot(b) ggmissing(c) ggfluctuation(d) ggpcpThe question was posed to me during an online exam.Asked question is from ggplot2 topic in portion Profiling, Simulation and Data Analysis of R Programming

_______ divides the time spend in each function by the total run time(a) “by.sum”(b) “by.total”(c) “by.self”(d) “by.del”This question was posed to me at a job interview.My doubt stems from R Profiler in portion Profiling, Simulation and Data Analysis of R Programming

Which of the following code is not profiled?(a) C(b) C++(c) Java(d) PHPThis question was addressed to me by my school principal while I was bunking the class.Question is from R Profiler topic in portion Profiling, Simulation and Data Analysis of R Programming

Which of the following function actually fits the linear model?(a) lm.time()(b) lm.date()(c) lm.fit()(d) lm.interval()This question was posed to me during an interview.I would like to ask this question from R Profiler topic in portion Profiling, Simulation and Data Analysis of R Programming

Which of the following creates a new ggplot plot from a data frame?(a) qplot_ggplot(b) ggplot.data.frame(c) ggfluctuation(d) ggmissplotI have been asked this question in final exam.This key question is from ggplot2 topic in portion Profiling, Simulation and Data Analysis of R Programming

Which of the following cuts numeric vector into intervals of equal length?(a) cut_interval(b) cut_time(c) cut_number(d) cut_dateThe question was asked in an international level competition.The query is from ggplot2 in section Profiling, Simulation and Data Analysis of R Programming

________ is used to create a plot to illustrate patterns of missing values.(a) ggmissplot(b) ggmissing(c) ggfluctuation(d) ggpcpThe question was posed to me in an interview.I'm obligated to ask this question of ggplot2 topic in chapter Profiling, Simulation and Data Analysis of R Programming

_________ time is time charged to the CPU(s) for the R expression.(a) elapsed(b) user(c) response(d) monitorI have been asked this question in an interview for job.I'd like to ask this question from R Profiler in division Profiling, Simulation and Data Analysis of R Programming

R comes with a ________ to help you optimize your code and improve its performance.(a) debugger(b) monitor(c) browser(d) profilerI got this question in an internship interview.I'd like to ask this question from R Profiler in division Profiling, Simulation and Data Analysis of R Programming

________ modify a ggplot or theme object by adding on new components.(a) +.gg(b) -.gg(c) /.gg(d) .ggI have been asked this question in unit test.I would like to ask this question from ggplot2 topic in chapter Profiling, Simulation and Data Analysis of R Programming