Legend control in R Programming - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to add a legend to the plot.

R Programming

plot(x, y, type = 'l')
legend('topright', legend = [1], col = 'blue', lty = 1)

Drag options to blanks, or click blank then click option'

Ac('Data Line')

B'Data Line'

CData Line

D['Data Line']

Attempts:

3 left

💡 Hint

Common Mistakes

Using an unquoted string causes an error.

Using square brackets is not valid in R for vectors.

The legend function expects the legend argument as a character vector, so c('Data Line') is correct.

2fill in blank

medium

Complete the code to set the legend title.

R Programming

plot(x, y, type = 'l')
legend('topright', legend = c('Data'), title = [1], col = 'red', lty = 1)

Drag options to blanks, or click blank then click option'

Ac('Data Title')

Bc(Data Title)

C'Data Title'

DData Title

Attempts:

3 left

💡 Hint

Common Mistakes

Not using quotes causes an error.

Using c() creates a vector, but title expects a single string.

The title argument expects a string, so it must be in quotes like 'Data Title'.

3fill in blank

hard

Fix the error in the legend position argument.

R Programming

plot(x, y, type = 'l')
legend([1], legend = c('Line'), col = 'green', lty = 1)

Drag options to blanks, or click blank then click option'

A'topright'

Btop right

Ctopright

Drighttop

Attempts:

3 left

💡 Hint

Common Mistakes

Using unquoted position names causes errors.

Using invalid position names causes the legend not to appear.

The position argument must be a string in quotes, so 'topright' is correct.

4fill in blank

hard

Fill both blanks to create a legend with two items and different colors.

R Programming

plot(x, y, type = 'l')
legend('bottomleft', legend = [1], col = [2], lty = 1)

Drag options to blanks, or click blank then click option'

Ac('Line1', 'Line2')

Bc('Line1')

Cc('red', 'blue')

Dc('green', 'yellow')

Attempts:

3 left

💡 Hint

Common Mistakes

Using only one label or one color causes mismatch errors.

Not using c() creates invalid arguments.

The legend needs two labels and two colors, so c('Line1', 'Line2') and c('red', 'blue') are correct.

5fill in blank

hard

Fill all three blanks to customize the legend with line types and a title.

R Programming

plot(x, y, type = 'l')
legend('top', legend = [1], col = [2], lty = [3], title = 'Legend')

Drag options to blanks, or click blank then click option'

Ac('A', 'B')

Bc('black', 'orange')

Cc(1, 2)

Dc('red', 'blue')

Attempts:

3 left

💡 Hint

Common Mistakes

Mismatched vector lengths cause errors.

Using color names not recognized by R causes warnings.

The legend labels are c('A', 'B'), colors c('black', 'orange'), and line types c(1, 2) for solid and dashed lines.