MATLAB 2D and 3D Plotting Questions and Answers

Question 1

A data analyst wants to display four different 2D plots in a single figure window, arranged in a 2x2 grid.
After creating the first plot in the top-left position, which command should they use to select the bottom-right position for the fourth plot?

Accepted Answer

subplot(2,2,4)

Answer

subplot(4,4,4)

Answer

subplot(2,2,1)

Answer

axes(2,2,4)

Question 2

Which of the following commands is used to create a 3D line plot (a helix, for example) from vectors `x`, `y`, and `z`?

Accepted Answer

plot3(x,y,z)

Answer

plot(x,y,z)

Answer

mesh(x,y,z)

Answer

surf(x,y,z)

Question 3

A user has generated a 2D plot and wants to ensure that any subsequent plotting commands add new lines to the same plot instead of replacing it. They also want to add a descriptive legend. Which sequence of commands is appropriate?

Accepted Answer

plot(x1,y1);
hold on;
plot(x2,y2);
legend('Data 1', 'Data 2');

Answer

figure;
plot(x1,y1);
plot(x2,y2);
legend('Data 1', 'Data 2');

Answer

subplot(1,2,1); plot(x1,y1);
subplot(1,2,2); plot(x2,y2);
legend('Data 1', 'Data 2');

Answer

plot(x1,y1,x2,y2);
label('Data 1', 'Data 2');

Question 4

What is the primary difference between the `surf(X,Y,Z)` and `mesh(X,Y,Z)` functions when visualizing a 3D dataset?

Accepted Answer

`mesh` creates a wireframe with colored edges, while `surf` creates a solid surface with colored faces.

Answer

`surf` is used for 2D data, while `mesh` is used for 3D data.

Answer

`mesh` connects data points with straight lines, while `surf` uses a polynomial interpolation.

Answer

There is no functional difference; they are aliases for the same plotting function.

Question 5

After creating a line plot with the command `p = plot(x, y);`, how can you change the color of the line to red using the plot handle `p`?

Accepted Answer

set(p, 'Color', 'red');

Answer

p.LineColor = 'red';

Answer

change(p, 'color', 'r');

Answer

color(p, 'red');

Question 6

A user wants to create a 2D plot of `sin(x)` and `cos(x)` on the same axes and label them appropriately in a legend. Which of the following code snippets will achieve this correctly?

Accepted Answer

x = 0:0.1:2*pi;
plot(x, sin(x), x, cos(x));
legend('sin(x)', 'cos(x)');

Answer

x = 0:0.1:2*pi;
plot(x, sin(x));
plot(x, cos(x));
legend('sin', 'cos');

Answer

x = 0:0.1:2*pi;
plot(x, sin(x));
legend('sin(x)');
hold on;
plot(x, cos(x));
legend('cos(x)');

Answer

x = 0:0.1:2*pi;
plot(x, sin(x) + cos(x));
legend('sin(x) and cos(x)');

A data analyst wants to display four different 2D plots in a single figure window, arranged in a 2x2 grid.After creating the first plot in the top-left position, which command should they use to select the bottom-right position for the fourth plot?

A data analyst wants to display four different 2D plots in a single figure window, arranged in a 2x2 grid.
After creating the first plot in the top-left position, which command should they use to select the bottom-right position for the fourth plot?