R Programming Mock Test 8

10%

Question 1 of 10

1. Which of the following will reverse the order of values in x?

rev(x)

max(x, na.rm=TRUE)

all(x)

x%in%y

Question 1 of 10

Question 2 of 10

2. Which of the following code drop the ith and jth column?

new <- old[,-n]

new <- old[,-c(i,j)]

new <- old[-n,]

new <- subset(old,logical)

Question 2 of 10

Question 3 of 10

3. Which of the following create a set of identity mappings?

aes_all

aes

ggorder

ggplot

Question 3 of 10

Question 4 of 10

4. _____ list the variables in the workspace.

rm(list=ls())

attach(mat)

rm(x)

ls()

Question 4 of 10

Question 5 of 10

5. Which of the following sets the size of the outer margins for the graph?

par(ask=TRUE)

par(mfrow=c(nrow,mcol))

par(ask=False)

par(omi=c(0,0,1,0) )

Question 5 of 10

Question 6 of 10

6. For barchart and _________ non-trivial methods exist for tables and arrays, documented at barchart.table.

xyplot

scatterplot

scatterplot & xyplot

dotplot

Question 6 of 10

Question 7 of 10

7. Point out the correct statement?

spread() function takes multiple columns

separate() makes “wide” data longer

Two functions are present for tidy data

gather() makes “wide” data longer

Question 7 of 10

Question 8 of 10

8. __________ produces bivariate scatterplots or time-series plots.

dotplot

bwplot

xyplot

barchart

Question 8 of 10

Question 9 of 10

9. Which of the following produces the variance covariance matrix?

mad(x, na.rm=TRUE)

sd(x, na.rm=TRUE)

fivenum(x, na.rm=TRUE)

var(x, na.rm=TRUE)

Question 9 of 10

Question 10 of 10

10. Which of the following is Mac menu command?

browser.workspace

a statistical transformation

browse.workspace

browse.works

Question 10 of 10