Labels, title, and legend in MATLAB - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this MATLAB plot labeling code?

Consider the following MATLAB code that plots a simple line and adds labels and a title. What text will appear as the x-axis label?

MATLAB

x = 1:5;
y = x.^2;
plot(x, y);
xlabel('Time (s)');
ylabel('Distance (m)');
title('Distance vs Time');

A Time (s)

B Distance (m)

C Distance vs Time

D x-axis

💡 Hint

Look for the function that sets the label for the x-axis.

The function xlabel('Time (s)') sets the label for the x-axis to 'Time (s)'.

❓ Predict Output

intermediate

What legend text appears in this MATLAB plot?

Given this MATLAB code, what text will appear in the legend?

MATLAB

x = 0:0.1:2*pi;
y1 = sin(x);
y2 = cos(x);
plot(x, y1, '-r', x, y2, '-b');
legend('Sine Wave', 'Cosine Wave');

A sin and cos

B Sine Wave and Cosine Wave

C Red and Blue lines

D Sine and Cosine

💡 Hint

Check the legend function arguments.

The legend function is called with 'Sine Wave' and 'Cosine Wave', so these exact texts appear in the legend.

🔧 Debug

advanced

Why does this MATLAB code not display the title?

This MATLAB code plots data and tries to add a title, but the title does not appear. What is the problem?

MATLAB

x = 1:10;
y = rand(1,10);
plot(x,y)
title = 'Random Data Plot';

A The plot command is missing a semicolon

B The x and y vectors have different lengths

C The y data is not sorted

D The title is assigned to a variable instead of calling the title() function

💡 Hint

Check how the title is set in MATLAB.

The code assigns a string to a variable named title instead of calling the title() function, so no title is displayed.

🧠 Conceptual

advanced

What happens if you call legend without arguments after plotting multiple lines?

In MATLAB, after plotting multiple lines, what does calling legend() with no arguments do?

A It automatically creates a legend using the DisplayName properties of plotted lines

B It clears any existing legend from the plot

C It creates an empty legend box

D It causes a syntax error

💡 Hint

Think about how MATLAB uses DisplayName properties in plots.

Calling legend() without arguments uses the DisplayName properties of plotted lines to create a legend automatically.

❓ Predict Output

expert

What is the output of this MATLAB code with multiple labels and legend?

Analyze this MATLAB code and determine what text appears as the y-axis label and what the legend shows.

MATLAB

x = linspace(0,1,5);
y1 = x;
y2 = x.^2;
plot(x,y1,'-o', x,y2,'-s');
ylabel('Value');
legend({'Linear','Quadratic'});
title('Comparison Plot');

A y-axis label: 'Comparison Plot'; legend: 'Linear' and 'Quadratic'

B y-axis label: 'Value'; legend: 'y1' and 'y2'

C y-axis label: 'Value'; legend: 'Linear' and 'Quadratic'

D y-axis label: 'Value'; legend: 'o' and 's'

💡 Hint

Check the ylabel and legend function arguments carefully.

ylabel('Value') sets the y-axis label to 'Value'. legend({'Linear','Quadratic'}) sets the legend text accordingly.