R Programming Language Certification Data Visualization & Graphics in R 3

Question 1

Which base R function produces a histogram of a numeric vector?

Accepted Answer

hist()

Answer

barplot()

Answer

plot()

Answer

density()

Question 2

What does the labs() function do in ggplot2?

Accepted Answer

Sets axis labels, title, and legend titles

Answer

Creates color palettes

Answer

Adjusts plot dimensions

Answer

Adds data labels to points

Question 3

Which ggplot2 geom is used to create a box plot?

Accepted Answer

geom_boxplot()

Answer

geom_box()

Answer

geom_whisker()

Answer

geom_iqr()

Question 4

Which R package provides the ColorBrewer palettes commonly used for categorical and sequential color scales in maps and charts?

Accepted Answer

RColorBrewer

Answer

colorspace

Answer

viridis

Answer

scales

Question 5

In ggplot2, which function sets fixed x and y axis limits on a plot?

Accepted Answer

xlim() and ylim()

Answer

set_limits()

Answer

axis_range()

Answer

coord_range()

Question 6

Which ggplot2 function allows you to arrange multiple separate plots in a grid layout?

Accepted Answer

patchwork or gridExtra

Answer

facet_grid()

Answer

layout()

Answer

par(mfrow=)